How Winter Affects Roses

This is a revision of my 12/27/2013 post, based on several good comments I have received from Dr. Gary Ritchie and a number of other readers.  Thanks for the enthusiastic responses from so many rosarians, whom I hold in high esteem.
 JRF 12/29/2013

At the peak of winter here in the cold zones, our roses are "winter protected" to help them survive the sub-zero temperatures of USDA zones 4, 5, and 6.  Most folks look out at their roses covered (hopefully) with a nice layer of snow and believe their roses are dormant; just waiting to thaw out, break dormancy and start growing again.  But wait....  Did you know that only species roses, such as Rosa Rugosa, Rosa Glauca, Rosa Gallica etc. go through a dormancy cycle and that all modern, repeat-blooming, "remontant" roses do not?  So what's going on here with modern roses in winter?

Before I try to answer that question, I want to say that I recently learned much of this from "Dormancy in Roses", an excellent four-part series in the American Rose, during 2013 and early 2014, by Dr. Gary Ritchie of Olympia, Washington (see footnote below).  I will quote Gary several times in this post and want to give him full credit for his research and opinions.  However, I also want to note that Gary's articles have raised some important issues for me, based on my many years of successfully growing modern roses in Minnesota; in particular, why keeping modern roses frozen hard in the winter is what keeps them alive, rather than killing them outright. This seems somewhat contrary to the conclusion of Part 4 of Gary's article, where he says:

"I've not seen data on specific cold hardiness of modern roses but experience indicates that it is modest at best. So, while we enjoy continuous bloom throughout the summer, we face the annual chore of winter protecting our roses.  Here in the moderate coastal Northwest, this requires no more than mounding up our plants in fall.  But in more extreme climates winter protection can be much more difficult and problematic -- sometimes even requiring burying the plants underground to assure their over-winter survival." 

Here is how I would re-phrase Gary’s quote (above) from my perspective in zone 4/5:

"I've not seen data on specific cold hardiness of modern roses, but experience indicates that, with good winter protection, most modern roses, including budded hybrid-teas, are very cold-hardy, as long as they are allowed to freeze solid and stay frozen all winter.  Here in Minnesota (zones 3, 4, and 5), winter protection begins with planting bud unions four to six inches deep, mounding with dirt or compost in the fall, and subsequently winter-protecting with leaves or hay after the ground freezes in late fall or early winter. Another alternative is the Minnesota Tip method of burying plants underground.  Both methods have as their objective keeping roses frozen throughout the winter; not to keep them from freezing, which is virtually impossible in our zone 4/5 winters."  (JRF Quote)

In other words, the whole purpose of winter-protecting roses in the cold zones, where the ground freezes from several inches to more than a foot down, is to keep roses from repeatedly freezing and thawing. The only exception to this might be the use of insulated R7.5 construction blankets, which are gaining popularity in Minnesota.  My friend and TCRC mainstay, Deb Keiser, who manages the Virginia Clemens Rose Garden in St. Cloud, believes that putting construction blankets down before the ground freezes keeps her roses from freezing in the first place (which is quite an achievement in St. Cloud!). But the principle is the same, whether the ground freezes under the blankets or not:  i.e., to keep your roses from repeatedly freezing and thawing.  This can be problematic here in the Twin Cities (now in zone 5) and even more so in zones 6 and 7, where mid-winter thaws are more frequent.  Take a look at my recent article on winter protection:

http://jack-rosarian.blogspot.com/2013/09/winter-protecting-your-roses.html


Here is how two of my rose beds looked on Christmas Day 2013:

Buck Earth Songs under a foot of snow insulation

Terraced Canadians and Bucks

Now, just in case I have given the impression that I'm not growing hybrid teas in Minnesota winters, here is my winter-protected Elina on a -2 F. afternoon in Edina.  The reason the leaf bag is showing under the snow is that we had a record-breaking 48 F. the day before I took this picture; a 50 degree swing!  And that's what winter protection is all about in zone 4/5: to keep the roses from thawing and re-freezing in these crazy temperature swings!

Above: Elina in a Minnesota Winter

Dr. Gary Ritchie's point about modern roses not going into dormancy is obviously correct. Unlike woody perennials like Rhododendron or lilacs, roses apparently do not have a dormancy "chilling requirement"  in order to generate next season's bloom cycle. Rather, as Gary says, modern roses, as remontant, repeat-blooming  plants, "by their very nature, fail to go dormant in winter. So they have a much-reduced ability to cold harden."  In other words, rose canes die back in winter because they do not sufficiently "cold harden" and this die-back can only be controlled at the crown or bud union levels by proper winter-protection, as described above.  This affirms something that I have advocated for many years, i.e., repeated applications of potassium in the fall to "cold-harden" rose canes before the first hard freeze. My experience, over more than 20 years, is that hardening rose canes off with a potassium feast has the effect of significantly reducing cane die back in the winter.  Please see my several articles about the "potassium feast":
http://jack-rosarian.blogspot.com/2012/08/potassium-special-k-ration-feast-for.html

http://jack-rosarian.blogspot.com/2013/10/rose-potassium-feast-application-6.html


But something else seems to be happening here

Over the last several years, as the Twin Cities metro has moved solidly into zone 5, my observations indicate that modern roses may exhibit a characteristic, which may be related to the chilling requirement inherent in plants that experience dormancy in winter.

Even though our winters are warmer, in terms of extreme minimum temperatures (EMT), they seem to be just as long, or perhaps even longer in certain years, thereby keeping our roses frozen for a longer period of time. For example, our ground (and therefore our roses) stayed frozen into late April or early May in 2013, and we had snow on the ground into early May.  This is 2-4 weeks later than normal. What happened in May, once the ground thawed out, was that the roses had a very hard time getting started and there seemed to be more die-back than usual, even with shrubs that are zone 3 and 4 hardy. One of our husband-wife TCRC members,who have had good success over the years planting their hybrid tea and shrub roses with bud-unions and root crowns six inches below ground level, and using minimal winter protection above ground, lost a number of roses in 2013, even though the same method had worked perfectly in colder EMT winters.

In other words, with a 2013 EMT of -13 (well above the median for zone 5), our roses actually seemed like they had been through a much harder winter.  So it would appear that the length of time roses are frozen, not just the low temperature in a given year, impacts survivability.  After all, if you think about it, frozen is frozen; the only thing that happens with a lower temperature is that the ground freezes deeper and the roses take longer to thaw out and start growing in the new season.  But what happens to them when the winter is so long that they can't start growing again in a timely way?  To my knowledge there is no scientific reasoning for this phenomenon.  However, I found a clue in Part III of Gary Ritchie's series, where he speaks of cold weather breaking dormancy in plants.  Speaking of dormant plants in the first person, he says:

 "...One way would be somehow to keep track of the amount of cold weather to which you had been exposed during winter.  After a certain number of hours or days of cold exposure had occurred you would have a clear indication that winter was finally over and it was safe to resume growth.  This is exactly what plants do...."

What he is saying is that dormant plants apparently have an internal clock mechanism buried deep in their DNA that tells them it's time to start growing again, after they have been exposed to a certain number of hours or days of cold weather.  However, what happens if that internal clock tells them it's time to grow and they're still frozen solid?

Now, this is pure conjecture on my part but, based on my observations in the past year, I would theorize that (1) modern roses, although they do not experience dormancy, might share a similar DNA clock mechanism with plants that do, such as their first-cousins, the species roses; and (2) the growth signal coming from within the plant might be distorted by longer than historically normal periods of remaining frozen, such that the plant's internal growth pattern is interrupted, or even curtailed altogether, thereby causing much slower growth or even plant death.  This could account for what I and a number of Minnesota friends experienced in our warmer, but longer than normal, winter of 2013.  This was truly something I had never seen in my near-lifetime of growing roses in zones 4, 5 and 6.

I had been thinking about this since last spring and Gary Ritchie's four-part series in the American Rose was such an “a-ha” moment for me, that I couldn't wait for the next installment to come.  Gary might not agree, but it seems logical to me that, while modern (non-species) roses do not experience dormancy, per se, they might share some form of the so called "chilling requirement" of species roses.  There is much we don't know about the effects of winter on roses but, by observing the effects of the weather anomalies we are currently experiencing, we can learn a lot about what makes our roses tick and how we can better protect them in winter.  Unfortunately, we can't do much about the undue length of some winters, except to realize that not all winter effects on roses are related to extreme low temperatures.

I would be very interested in the reactions of readers to the theories I have set forth in this article.  My findings are 100% empirical and can be enhanced by the observations of others growing roses in cold zones. As always, please let me know what you think.

Jack Falker
jack@falkerinvestments.com
December 27, 2013

Note:  Dr. Gary Ritchie's four articles on Dormancy appeared in the May/June, July/August, and September/October, 2013, and the January/February 2014 issues of the American Rose.  By the way, articles like these, written by outstanding rose-scientists like Gary Ritchie, are one more reason that all rosarians should be members of the American Rose Society!

Rose Potassium Feast: Application #6

I put down the sixth and final liquid potassium application on my roses yesterday, getting them ready for winter.  In case you haven't been following my blog posts on this subject, here is a synopsis:

In the six weeks before the first hard freeze (i.e., down to about 25 F. at night), give your roses a weekly "potassium feast" in each of those six weeks.  Potassium blocks the growth-promoting effects of nitrogen and phosphorous, thereby hardening the canes in time for winter.  I've been doing this for more than 20 years and I honestly can't remember the last time I lost a rose to winter weather here in Minnesota. Of course, I do other things to protect my roses from the Minnesota winter, as well.  Here is my recent article on winter protecting your roses:  http://jack-rosarian.blogspot.com/2013/09/winter-protecting-your-roses.html

Here is a quote from Burpee’s American Gardening Series book Roses, by Suzanne Frutig Bales:

“Potassium is an important mineral for sturdy stems and foliage.  Weekly feeds of a gallon of liquid potassium (1 tablespoon of muriate of potash (0-0-62), dissolved in 3 gallons of water) per bush, or a granulated feeding of potash magnesium (0-0-22), during the six weeks before the bushes go dormant, will give the bushes an additional boost for winter, extending their hardiness into another hardiness zone, perhaps two.  Excess potassium, when available in greater amounts than nitrogen and phosphorus, is known as the ‘potassium feast’.  It will block the growth-promoting effects of nitrogen and phosphorus, hardening the canes in time for winter.” 

To clarify:  The proportions are: 1 TBP Muriate of Potash per 3 gallons of water (or 1 TSP per gallon).  So mixing in a 30 gallon trash container, you would use 10 TBP.  Apply one gallon of this mixture on each rose every week.  That’s not very much, but remember you’re repeating it six times. 

I begin my roses’ potassium feast in the second or third week of September.  That takes me through the end of October or beginning of November, which is about as late as I want to go.  There have been years, perhaps when I started a little too late, that I’ve had to thaw out my hose or turn off my water and turn it back on again in order to complete the sixth treatment.  My advice is don’t wait too long, because it’s better to be too early than too late with this. 

Here are a few pictures of yesterday's application, taken by Mary Eileen (a.k.a "The Head Deadheader"):

Each rose gets one gallon of the mixture for six consecutive weeks.  It has the added advantage of hydrating the plants weekly as we head into winter.  Note that it was a very nice day yesterday; a lot nicer than it has been for many of my sixth applications.

I mix the potassium in 34 and 64 gallon trash containers and pump it out with an inexpensive sump pump, through a hose and watering wand (you can see the pump's electrical cord going into the container). This little trick of using a sump-pump for applying liquid fertilizers is a huge work-saver throughout the growing season. Muriate of Potash is a reddish, crystalline substance that doesn't dissolve as easy as most liquid fertilizers.  I use as much water pressure as I can muster, through a nozzle turned on all the way, to get it dissolved.  The sump-pump goes in after the tank is full.  Note how the potassium has red-stained the trash container in the picture below.  It will do that to your clothes too, but it washes out (eventually)  :)

Here I am with the 64 gallon container working on four of my Buck Earth Song plants.

I get Muriate of Potash (0-0-62) in 50-pound bags at Waconia Farm Supply, which is exactly 10 miles past the Minnesota Landscape Arboretum in Waconia.  A 50-pound bag of Muriate of Potash costs about $25 and lasts me five years or more.  For those of you outside of Minnesota, you will need to find a real farm supply store because it's pretty unlikely that you will find Muriate of Potash at your local nursery. 

  

After about the third-week’s application, you will begin to notice that the canes of your roses are turning a pretty shade of deep red, so you can actually see them hardening-off for the winter, which is fun to watch. 

 I believe that this method of winter protection is particularly interesting for northern gardeners, as we see the continuing effects of climate change in the rose garden. While putting on liquid-potassium for six weeks seems to be a lot of extra work, I think it can ultimately reduce the overall work of winter protection, once you gain confidence using it in your own garden. 

Here are two of my articles on the "potassium feast" from last year, as well as my recent article about winter protecting your roses:

http://jack-rosarian.blogspot.com/2012/08/potassium-special-k-ration-feast-for.html

http://jack-rosarian.blogspot.com/2012/10/potassium-follow-up.html

http://jack-rosarian.blogspot.com/2013/09/winter-protecting-your-roses.html

Vole Defense!

Considering a turn on an old saying, that a good defense begins with a good offense, I thought everyone would like to see our offensive effort to defend against voles this fall.  His name is Crackie, he's a six-year old Maine Coon and, needless to say, he's a mouser.

Voles are feisty; as Crackie toyed with it, it fought back aggressively but the cat flipped it upside down and then I went to get my shovel to finish it off.  Crackie didn't like me taking away his new play thing, so I had to give him some treats.

In case you missed it, here's my most recent post on vole control in the rose garden. It also

contains two other links to vole articles I wrote last year.

http://theminnesotarosegardener.blogspot.com/2013/09/voles-and-castor-oil.html

One of the things I mention is that, because cats go after voles, you should be very careful to use the right kind of mouse bait to kill them.  Here's a quote from my original article: 

Rodent Baits:  Killing voles is desirable, before they over-run you, but this is a touchy subject because rodent baits can also affect other animals, like neighborhood cats and dogs.  The common rodent bait that you find in most stores is an anti-coagulant poison, which, when eaten a couple of times, stays in the intestines, causes massive internal bleeding and kills the animal.  I used it in my rose beds for years, without thinking, until about five years ago when we got a new kitten and he managed to find a mouse or vole that had eaten it, in among the winter-protected roses.  I will save you the terrible details, but it resulted in a very large emergency veterinary bill to save this humane society kitty and, fortunately, he is still with us (but he used two or three of his nine lives on that one).

After that experience, I went to work researching what other non-coagulant rodent baits might be on the market, and I found one.  The brand name is "Eraze", made by Motomco, the same company that makes the anti-coagulant baits.  The active ingredient in this one is Zinc Phosphide, which is nonetheless a poison, but acts in a different way, killing small animals immediately after ingestion.  There are conflicting opinions on this, but an article by Michigan State University indicates that it is less lethal to larger animals, such as cats and dogs, because their normal reaction after ingesting it would be to regurgitate it rather than digest it.  There is no question that it would kill any animal if eaten in sufficient quantity, but it apparently is less dangerous because it kills the rodent and dissipates rather than staying in the animal as the anti-coagulant does, thus potentially transferring to another animal or predatory bird (owl or hawk) that might eat the dead or dying rodent, as we believe our kitten did.  Note that Motomco also makes a similar product labeled as mole bait that uses Zinc Phosphide, so if you can't find Eraze, you can use the mole bait (check the label to be sure).  Other companies also offer Zinc Phosphide under different brand names.

My first line of defense in controlling voles is castor oil (and Crackie).  My second line of defense is  zinc phosphide baits in small tin cans, carefully placed around the roses after my winter protection goes on the beds.  I'm pretty sure that Crackie can't get at the cans and that, if he does bite into a dead vole, he's not likely to die from residual Zinc Phosphide in the animal.

And we don't want to hurt Crackie.  He's a good kid!

Starbucks Coffee Grounds for your Roses

Starbucks doesn't like to throw their grounds in the trash, knowing that gardeners can use them organically.  At one time, they even had special bags labelled "Grounds for your Garden".  So don't be shy about going into your local Starbucks and asking for grounds.

I've said a lot about the benefits of using coffee grounds on your roses.  Here are my postings on the subject:

http://jack-rosarian.blogspot.com/2013/03/coffee-grounds-and-roses.html

http://jack-rosarian.blogspot.com/2013/05/gettin-wormy.html

Last Sunday morning, after finishing our coffee and reading the paper, Mary Eileen, my chief deadheader and best buddy of nearly 50 years, took my picture coming out of Starbucks with a 30 pound bag of grounds, destined for the compost pile that will be mounded around the roses  in preparation for winter, in a few weeks.

Here's how the bag looked when opened up.  A lot of expensive lattes went into that brown gold.

And here's how my compost  pile looks with all the grounds worked in.  It's amazing to see how many worms surface when you turn over the pile.  All of this will be going on the roses in a few weeks, when we do our winter protection.  That's Butternut and Zucchini squash at the back of the pile.  It flourishes there, as well. Yum!

Voles and Castor Oil

I was delighted to see Ted Mills' "Rose Doc" article "Voluminous Voles" in the September/October 2013 issue of American Rose.  Ted's articles are always great and are just one of the many benefits of belonging to the American Rose Society.

Ted does an excellent job of describing voles and why they are such a pain for all rosarians, especially those of us in the north who winter protect our beds and thereby inadvertently create winter habitats with unlimited tender food for these ravenous little creatures.  If you've ever had an entire rose bed destroyed by voles totally girdling the canes of every rose, right at ground level, you know exactly what I mean.

Ted gives some good suggestions and warnings about using rodent poison and mentions a product that I hadn't heard about and an am going to look for: Shake Away Rodent Repellent, but he apparently hasn't heard about the best repellent of all:  Castor Oil!

I published an article "Voles!" in October 2012, which mentions many of the same things Ted does and also provides some pictures in living color of these nasty little critters.  I also provided everything you need to know about using castor oil as a vole repellent, as well as a very good video on the subject from a New Hampshire hosta nurseryman.  Here is my article:
http://theminnesotarosegardener.blogspot.com/2012/10/voles-and-roses.html

I also published a follow-on article: "More About Voles and Castor Oil" in November 2012. And here is that article:
http://theminnesotarosegardener.blogspot.com/2012/11/more-about-voles-and-castor-oil.html

I have been using castor oil, mixed with soap and water, on my beds for the last few years, and I believe I can now say with certainty that it does repel voles.  Just be sure to use it liberally in all of your beds and the voles will go elsewhere. Remember, however, that "elsewhere" might be somewhere else in your garden; in my case last year they chewed almost all the way around the trunk of a new flowering crab tree, within about 30 feet of one of my rose beds.  Needless to say, I will be putting the castor oil mixture around a few other tasty plants this fall.

As always, feel free to comment below or send me an e-mail:  jack@falkerinvestments.com


Jack Falker
September 17, 2013

Winter Protecting Your Roses

Well it's 92 degrees in Minneapolis today;  so it's a great time to talk about winter protection!

What you do for winter in your rose garden depends a lot on where you live, of course, but one basic principle applies if you live in a cold zone, i.e. USDA Zones 3, 4, 5 and parts of 6.  Your objective is to keep your roses frozen; not to keep then from freezing!  There seems to be a lot of confusion about that and thus we have nurseries selling styrofoam rose cones, which serve as little ovens in the winter when the sun shines on them, causing plants to freeze and thaw repeatedly, thereby killing them.

But before we discuss actual protection methods, here's something everyone in the north should consider doing about six weeks before your first hard freeze (i.e., down to about 25 F. at night):  Give your roses a weekly "potassium feast" in each of those six weeks.  Potassium blocks the growth-promoting effects of nitrogen and phosphorous, thereby hardening the canes in time for winter.  I've been doing this for more than 20 years and I honestly can't remember the last time I lost a rose to winter weather here in Minnesota.  Take a look at my article: "Potassium: A Special K-Ration Feast For Your Roses", published in August 2012:

http://theminnesotarosegardener.blogspot.com/2012/08/potassium-special-k-ration-feast-for.html as well as my follow on article that shows the effect of the potassium on the plants: 

http://theminnesotarosegardener.blogspot.com/2012/10/follow-up-on-potassium-feast-and-air.html

So, after your roses are hardened off, what's next?  As those of you who have read my previous articles know, I am not a believer in the "Minnesota Tip".  I tipped my roses for many years but always felt that it was not a horticulturally sound practice to partially uproot your roses and cover them with dirt in mid to late October, when many of them were still in bloom, i.e. not even close to being naturally dormant.  The longer I did it, the more my gardening instincts (not to mention my back) kept telling me I should be doing something different.  Take a look at my August 2012 blog post:  "No Tipping Please!":

http://theminnesotarosegardener.blogspot.com/2012/08/no-tipping-please.html .

Besides being horticulturally unsound, the best reason I can think of for not tipping your roses is that it's simply unnecessary, unless you live well north of the Twin Cities, and even then I believe there are better methods (which I will discuss below). Take a look at the chart I developed, using Minnesota Climatology records, showing the progression of extreme minimum temperatures (EMT) in every winter since 1963.  As you can see, in the last 17 years there have been only four winters that have fallen in Zone 4 and, studying the climatology records more closely, those deep-freezes lasted only a couple of days, compared with winters in the 60s and 70s, when the deep-freezes lasted for weeks at a time, with daytime temperatures not rising above zero Fahrenheit. Now look at the slope of the trend line, moving steadily upward toward Zone 6, and note that nine of those 17 winters have actually been above the median of Zone 5, making them closer to Zone 6 than Zone 4.  So, why protect your roses for Zone 4 winters when our winters are approaching Zone 6, especially when you consider that your task is just to keep your roses frozen?

Many people, who have been tipping their roses for years, feel trapped in the procedure because the bud unions of their grafted hybrid teas are at or above the surface of the ground.  My advice to these folks is that, instead of tipping your roses this year, dig them out entirely, taking a good root ball, heel them into a trench, a foot or so deep, and cover them with a good layer of dirt and mulch (to keep them frozen).  Then in the spring replant them in the same place, except this time plant them with the bud unions five or six inches below the surface.  If your garden is large, you could do it in stages, some this year, some next year etc.  Another alternative might be to raise the level of soil in your beds so that your bud unions are at least slightly below grade.

Once your bud unions are at least somewhat below grade or, even better, if your roses are growing on their own roots, here is what I recommend for winter protection.  Year-round, mulch your beds with at least three inches of wood chips overall, and in the late fall pull more of those chips up around your plants from the area surrounding them, so you have five or six inches of chips around every plant (in the summer fewer chips are desirable around the plants, to work in fertilizer, coffee grounds etc.).  Next, mound a couple of shovels full of compost from your mulch pile around every plant.  My mulch pile is primarily shredded oak leaves from last fall and hundreds of pounds of composted Starbucks coffee grounds that I collect regularly.  See "Coffee Grounds and Roses":
http://theminnesotarosegardener.blogspot.com/2013/03/coffee-grounds-and-roses.html.
This compost is full of worms and worm castings, so it's just what the roses need in the spring when I spread out the wood chips and work the compost into the ground.  

Next, when it starts getting cold and your roses have stopped blooming, bind them into bundles and cut them down to about 12-18 inches. (Don't worry, you're not losing anything here; what you want is the strong new growth you will get in the spring.)  Here's what this looks like before I cut them back: 

Also, see "The Big Coverup":
 http://theminnesotarosegardener.blogspot.com/2012/11/the-big-coverup.html

The next step is to prepare a bunch of half-full, regular plastic leaf bags.  For heaven's sake, don't use the compostable leaf bags (as I did one winter, picking them up from neighbors' leaf bag piles).  They break down over the winter and leave you with piles of leaves to clean up!  When you put these bags on your roses will differ, depending on where you live.  In zones 3, 4, 5, and colder parts of 6 (like Chicago), wait until the ground freezes before putting them on.  Now, with the objective of keeping your roses frozen, one-by-one slit open the bottoms of your leaf bags and shove them down on each of your plants, flush with the mounds. In higher cold zones, i.e. warmer parts of zone 6 (like Detroit, Cleveland, Kansas City, Indianapolis, St. Louis, etc. you can probably just rely on the mounding and wait to see if you get snow cover to insulate your beds.  If not, I would put the leaf bags on the plants in the latter part of December, as a precaution against freezing and thawing.  

So, can you see how this approach will protect your roses just as well as the "Minnesota Tip"?  When you start to carefully roll the bags off your roses in the spring (to keep as many of the leaves in the bags as possible for disposal or mulching), you will find that many of the bags are still frozen to the mounds and that the roses are encased in blocks of ice; exactly as you wanted them to be.  In fact, depending on how quickly it warms up, it may take longer for these mounds to thaw than the tipped roses.  In March of 2012, we had a very early warm up into the 80s and the beds began to thaw, such that it appeared that it was time to take the bags off the plants.  I was suspicious that it could get cold again and, thankfully, I just rolled the bags back a little to allow the plants to start thawing.  Sure enough, in a few days, night-time temps dropped into the teens and I was able to push the bags back over all the plants to insulate them from the cold snap.  The apple trees all over southern Minnesota and the cherry trees in northwestern Michigan had all bloomed, and substantial parts of both crops were ruined.

Summarizing,

• Give your roses a six-week potassium feast to harden up their canes for winter.
• Use at least 3 inches of wood chips in your beds, year-round, and more around your roses in the fall.
• Mound with good compost, including lots of coffee grounds.
• Tie up your roses in bundles and cut them back to 12-18 inches when they stop blooming.
• Cover them with half-filled leaf bags after the ground has frozen.
• Keep your roses frozen until spring comes over your window sill!

Let me know if you have any questions.  I would love to hear from readers in the cold zones of Europe, especially in Siberia (where my Volga-Deutsch father was born in 1902).

Please comment in the space below or send an e-mail to:  jack@falkerinvestments.com .

Jack Falker

September 2013

Mistakes!

It's important for my readers to know that many of the things I talk about in these pages were learned by trial and error; a lot of errors!

For example, in a non-rosy matter this summer, I asked a commercial sprayer, who was spraying fungicide on my neighbor's flowering crabs, to also spray my Harrelson-Red apple tree.  He told me he was spraying a systemic and stated the chemical name which sounded vaguely familiar, but it didn't register with me and I didn't check it out.  Unfortunately, I later found out that what he sprayed was the systemic fungicide Banner-Maxx, which I use as a systemic blackspot inhibitor on my roses, along with Manzate.  Banner-Maxx is labeled only for fruit trees that will not be used for human consumption and there are now hundreds of beautiful apples on that tree that I will have to throw away this fall.  I really should have known better, but I won't make that mistake again, for sure.  To make matters worse, that boner cost me ten bucks!

I also just learned something else in the last week about my roses, which have been absolutely beautiful all summer.  I started seeing lots of shiny leaves, like something sticky had been sprayed on the plants.  After a little checking around, I discovered that what I was seeing was "honeydew", the sticky excretion of thousands of aphids that had infested several of my beds.  I  haven't seen aphids in any quantity in my beds for years and that really started me scratching my head.  I have always cultivated beneficial wasps and flies in my gardens that feast on a variety of insects, especially aphids, so what changed?  Where did the beneficials go and why this infestation?  I immediately water-washed the plants with my bug blaster and sprayed with insecticidal soap, and then with a combination of apple cider vinegar and Castile soap, which killed a bunch of aphids, but not nearly enough to keep up with the supply that was attacking my plants.  After a few days the plants were looking really stressed and today I cut off lots of new growth that was starting to die back.  Tomorrow, I will be spraying with imidacloprid, which I know will take them down immediately, but I really hadn't wanted to do that this year, because of its potential effect on bees

I immediately suspected that I had made another foolish mistake and I read everything I could find on the internet about aphid infestations.  What I discovered is that by over-spraying certain insecticides, such as acephates (like Orthene)and pyrethroids (like Demand CS) you can kill off all the beneficial insects, which then gives rise to aphid infestation.  And I really had no idea what aphids would do to the roses, once they are uncontrolled by beneficial insects.

Those of you who have followed my blogs for the last year or so know that I have been successfully experimenting with the pyrethroid Lambda Cyhalothrin (Demand CS) for controlling Japanese Beetles.  Since it is also labelled for spider mites, I thought that I could make it do double duty with both spider mites and JBs. Mistake! I ended up overusing it this summer and, to make matters worse, since it is labeled for aphids, I used it again to try and wipe out the aphid infestation, which failed completely and the infestation just got worse.

So by making this seemingly foolish mistake, I have learned the limitations of overusing a pyrethroid, which has a very important application in controlling JBs and which I want to be able to use in the future.  The lesson is to use it very sparingly and only when a true JB infestation occurs, which we really haven't seen this summer.  (Picking the beetles by hand and drowning them in soapy water is still the preferable way to control JBs and I must admit I just got lazy on that front this summer, in favor of spraying Demand CS, which works so well.

The other thing I learned is that the combination of Castile soap and apple cider Vinegar controls aphids, although not enough to forestall an infestation.  I had given up on it earlier this summer when it didn't work on thrips but, since I wasn't seeing aphids at that time, I didn't realize that it was working to hold them down.  I will definitely return to this very benign approach toward aphid control, as soon as I achieve a "knock-down" to save my beds.  Here's my post on Castile soap:
 http://jack-rosarian.blogspot.com/2013/03/got-castile-soap.html

So, another valuable lesson learned.  But remember that if you aren't trying new things and, yes, making a few mistakes, you will never learn how things should best be done.  In that regard, you can make an educated guess that many of the things I discuss in these pages have been learned and perfected by making mistakes.

Jack Falker
09-05-2013

The "Minnesota Rose Gardener's" Rose Gardens

I thought the "proof of the pudding" of the "Minnesota Rose Gardener" blog would be to show all of my rose gardens at their peak in mid-August.  So here they all are, with comments on each:

 This is my main Earth Song bed.  Earth Song is our favorite rose; very disease-resistant, winter-hardy, fragrant, and beautiful, and makes a long-lasting cut flower.  It's also one of Griffith Buck's only Grandifloras, so it's especially good as an exhibition rose.  Incidentally, I propagated all the roses in this bed from air layers and stem cuttings.

The bed in the background is temporary, for this summer only, and takes the place of a 5,000 gallon koi pond that we removed this spring.  I wanted to do something with the 14 cubic yards of good black dirt that we poured in the hole, so I bought about 10 packs of zinnia and cosmo seeds, plus the cleome aleady coming up in other parts of my garden, and spread them all around. It was a really big transplanting and thinning job, but it's really beautiful right now.  More on that bed later, because my Morden Centennials are hiding behind all of those annuals.

This bed is in the front of my house on the northeast corner and includes Buck Earth Songs in the foreground and Buck Carefree Beauties in the rest of the bed.  The Earth Song in the foreground (a very big plant) is the parent of most of the other Earth Songs in my garden.

This is the other end of the front Carefree Beauty/Earth Song Bed, with Carefree Beauty in the foreground. These roses are upwards of twenty years old.

These are four Earth Songs at the front, southeast corner of our house, right by the garage.  Did I mention that we love this rose?

These are the Morden Centennials behind the area where the koi pond was.  They have a few nice peony plants mixed-in for spring color.  To the left are the temporary cleome, zinnias and cosmos.  My mom called the cleome "spider plants".  As anyone who grows them knows, once you plant cleome/spider plants, they seed themselves exponentially every year.  If they weren't so pretty, we'd probably call them invasive weeds! I usually let them grow around my mulch pile as a barrier.  The down side of that is they pop up the next year everywhere you spread the mulch, including the rose beds.  Fortunately, they're easy to pull.  :)

Here's another view of our Morden Centennials, which shows the electric deer-fence behind the garden. The back of our yard is in the watershed of Nine Mile Creek, which flows into the Minnesota River and thence to the Mississippi (as does just about everything in Minneapolis).  Accordingly, we have a large herd of deer that lives along the creek wetlands behind us; and, of course, their favorite food is roses.  The electric fence is baited every night with aluminum-foil strips smeared with both peanut butter and a deer attractant. Licking the fence really gets their attention.  It uses a standard, farm, cattle/horse fence controller and is called the "Minnesota Deer Trick".

This bed is on the North end of our yard and features two Robustas and a big raspberry patch, which belongs to our granddaughter Cosette.  This is Japanese Beetle heaven at this time of year.  Here's a little picture of a pretty, single Robusta:

These are two terraced beds at the back of our house, behind our three-season porch/deck.  They include Buck Earth Song, Folksinger, Prairie Harvest, Honey Sweet, Paloma Blanca, Hawkeye Belle and Prairie Star, as well as Morden Blush, Winnipeg Parks and, last but not least, Dr. David Zlesak's gorgeous, yellow, "Number 7" (which we are very privileged to grow).

And now, finally, here's the old "Minnesota Rose Gardener" himself.  Photo credit to Mary Eileen, my sweet wife of 49 years, who puts up with a lot and is absolutely the best dead-header in all of Minnesota!
(Yes, I'm sitting on the sweet alyssum, but who cares!)    :)


Jack Falker
August 15, 2013

Mind Your pH!

Do you know the right pH for growing roses?  And do you know the pH of your soil right now?  If not, you're flying blind and you're eventually going to have problems; just like I did a few years ago, when virtually all of my roses in two beds stopped growing after their initial spring bloom.   I knew something was wrong when pouring on high-nitrogen Miracle-Gro had no effect. The roses acted like they didn't even know it was there; and that's about right because they couldn't "feel" its effect.  I found out later that the pH in those beds was way too high (about 7.5) and that I made it that way through an unfortunate series of organic gardening mistakes, the biggest of which was using way too much horse and cow manure; a condition I'm still trying to fully correct.  More about that later.

The measurement of relative acidity or alkalinity of soil is its pH, where neutral is a pH of 7.0, which is the pH of distilled water.  A pH below 7.0 means that soil is acidic and above 7.0 means it's alkaline.  Roses need a fairly acidic condition and if they don't have it they simply stop growing (just like mine did), because they can't absorb nutrients; plus they develop an iron deficiency, which I could definitely see in mine.

Consulting my collection of rose books on the subject of pH, they all say about the same thing:  that the ideal pH range for roses is between 6.0 and 6.8 (a mid-point of 6.4).  However, exchanging e-mails with Dr. Peter Bierman, retired Professor of Soil, Water and Climate at the University of Minnesota, after an excellent presentation he made to the Twin Cities Rose Club (TCRC) in February 2011, he concluded: "Because many roses are susceptible to iron deficiency at high pH, I think I'll stick with the range of 5.5 to 6.5." That's a mid-point of 6.0 and I like Dr. Bierman's slightly more acidic conclusion, based on my experience.  So,that's all you need to know about the right pH for growing roses; just memorize it and head out to recess!

Now, how do you find out the pH of your soil?  Well, one way to do it is to take a soil sample and send it to a soil measurement laboratory.  Around here, that would be the University of Minnesota Extension Service. The problem with that, however, is that you will only find out the pH of one or two spots in your garden.  What you really need to know is the pH of your soil in many spots in your garden, preferably at the bases of several roses in each bed.  The only way to do that is to own an inexpensive pH meter and make it one of the most important tools in your garden.  (Forget about using litmus paper pH measuring strips; they're not accurate enough and hard to use).   Rosemania.com offers several pH meters; I use their most inexpensive model and it works fine. Here's the address of that page on Rosemania’s website:

 http://rosemania.com/shopsite_sc/store/html/page17.html .

When using a pH meter you must first wet the soil you are measuring with distilled water, which has a neutral pH.  This is important, because you don't want your measurement of your soil to be influenced by the pH of the tap water.

Can you tell from the scratches on my Kelway pH meter, above, that it gets used a lot?

So, how do you control pH in your garden to keep it in that 6.0 range for your roses?  Well, the first thing is not to put alkaline composts, like animal manures, on your garden unless you supplement them with something acidic, like peat.  As mentioned above, I learned this the hard way.  I grew up in a rose garden and, whenever we visited my uncle's dairy farm, my dad always brought home a couple of 5 gallon buckets of rotted cow manure for his rose beds.  In retrospect, that small amount of manure would not have elevated his pH, but I thought that if my dad had beautiful roses using manure, more would be better for me.  So I set out to get trailer loads of horse and cow manure every year and I spread all that poop liberally on my beds, especially when I mounded my roses for winter.  Well, that, of course, was a mistake, as I mentioned above, when my pH went up to an unsustainable level of 7.5.  I subsequently learned from a very knowledgeable dairy farmer in Wisconsin, who sells composted cow manure (Cowsmo), that his pH is 7.3 and he advised me not to use it without peat to bring its pH down.  That's when the light went on.  My organic fertilizing was doing more harm than good!

In that regard, we recently had several organic fertilizer vendors come to a TCRC meeting to talk about their wares.  One of them was selling little bags of "Alpaca Pearls", i.e. alpaca poop, from their farm.  Knowing that animal fertilizers have high pH, I asked if they knew the pH of their product.  They did not but, to their credit, they subsequently had it measured and reported back that it is 8.3!  So Alpaca Pearls turns out to be the wrong thing to put on your roses, along with other animal manures.

I have learned from all this that green, organic manure, like coffee grounds, is the right thing to use on your roses.  Coffee has a perfect pH for roses of 6.2, has a decent nitrogen content, and is a perfect medium for nurturing worms and their castings (poop) around your roses.  See my two recent posts about using coffee grounds in the garden: http://jack-rosarian.blogspot.com/2013/03/coffee-grounds-and-roses.html and http://jack-rosarian.blogspot.com/2013/05/gettin-wormy.html

So what should you do if your roses won't grow and you find out, like I did, that your pH is too high?  Well, first, get started and be consistent with the coffee grounds, but that won't be enough to make a quick correction.  Here's a quote from a University of Minnesota paper on the subject by Dr. Bierman:  "Elemental sulfur is the most commonly used material to lower soil pH.... Iron sulfate also lowers soil pH and it acts much more rapidly than elemental sulfur (2 to 3 weeks vs. 3 to 4 months)."  Dr.  Bierman also points out that elevated pH drains roses of iron, so using iron sulfate to lower your pH also provides a needed dose of iron.

I use both elemental sulfur and iron sulfate in my garden.  Garden sulfur is available around here, inexpensively, in 25 pound bags, at Mills Fleet Farm, and iron sulfate is available in 50 pound bags at Waconia Farm Supply.  We have lots of farm stores in Minnesota, which is nice for serious gardeners, but you may have to look around a bit more in other areas.  Suburban garden centers sell these products in small containers at ridiculous prices, so I advise finding a farm store and doing the necessary driving to get there.

I have also found that using acidic Miracle-Gro or Schultz fertilizers, labeled for azaleas and rhododendrons, helps with the pH lowering process, in that, while you are treating the underlying problem with sulfur or iron sulfate, your roses will start absorbing nitrogen administered with a dose of acidity. As a matter of fact, unless your pH is under 6.0 already, a dose of acidic liquid fertilizer on your roses in the spring would be a good idea.  It's what I do with my beds.

I haven't mentioned the potential need to increase soil pH because it generally is not an issue with roses.  However, if for some reason your pH is below 5.5, repeated doses of limestone (lime) will increase pH back into the 6.0 range, over time.  But, be careful you don’t elevate it above 6.5 in the process.

Just before publishing this post, I measured the pH at the base of several plants in my Earth Song bed, which still had elevated pH last summer.  I had treated it with iron sulfate last year and put a good dose of elemental sulfur around each plant when I winter-protected the plants last fall.  To my pleasant surprise, the pH has dropped to 6.0 through the whole bed! And, of course, the roses are performing better than they have in quite some time.

Minding your pH is one of the most important things you can do to raise healthy roses.  I suggest that rose clubs should own a couple of pH meters and loan them out to members.  In addition, consulting rosarians should consider providing pH measurements to members, either with the club’s meters or their own.

Jack Falker

June 20, 2013

Gettin' Wormy

At the April meeting of the Twin Cities Rose Club,  we had a presentation by a local vermiculture farmer offering worm castings (worm poop) as rose fertilizer.  It was five bucks for a cute little five pound bag, which wouldn't seem to go too far in a garden with 100 plus roses.  So, it's pretty expensive fertilizer, especially given the fact you can make all the worm poop you'd ever need for free, if you work at it a little bit.  Nevertheless, folks walked out with multiple bags of worm castings in their arms.  It reminded me of the old saw: "Selling Ice to Eskimos".  Lots of Eskimo rosarians here in Minnesota!

If you have an active mulch pile, you have worms pooping for you every day.  All you have to do is put it on your roses (that's what the mulch is for).  And, if you follow the advice in my last blog, "Coffee Grounds and Roses" you'll have more worm poop than you'll know what to do with. In fact, at a buck a pound I may put some up in a cute little bag of my own for the next TCRC Eskimo meeting.

Here's a quote from that blog:

“What makes coffee grounds so wonderful in the garden anyway?  Earthworms love them.  They make a decent fertilizer.  You can use them as mulch or as a green ingredient in the compost pile….  Organic gardeners know that earthworms are essential to a healthy garden.  When it comes to improving soil structure and water-holding capacity, earthworms can’t be beat….  While earthworms will eat most any organic matter, coffee grounds are like earthworm candy.”
(From The American Rose “A Cuppa Joe”, by Paulette Mouchet)

And here's the address of that blog, in case you missed it:

http://jack-rosarian.blogspot.com/2013/03/coffee-grounds-and-roses.html

I compost with coffee grounds and shredded oak leaves, all of which goes on my roses over the summer and especially in the fall, when I mound my roses for the winter.  All of that works its way down in the ground in the spring, complete with worms to poop at will around every rose.  In economics and finance, we would call that the "multiplier effect".  Here's a recent picture of my mulch pile this spring with about 500 pounds of Starbucks' finest sitting right in the middle. (Can you just imagine the market value of all those lattes?)  After I took this picture, I took my rake and covered the grounds with shredded oak leaves that have been composting under the snow all winter, just before it started raining today.  That ought to get the worms pooping in style!  Little bag of worm poop anyone?

Coffee Grounds and Roses

One of the best kept secrets in rose gardening is coffee grounds.  Most people know they’re good compost, but have no idea of what they’ll do for the soil in your rose garden.

In the March/April 2011 issue of the American Rose there was an excellent article called “A Cuppa Joe”, by Paulette Mouchet of Acton, California, which was the best explanation of using grounds in the garden I've seen.  Here is an excerpt:

“What makes coffee grounds so wonderful in the garden anyway?  Earthworms love them.  They make a decent fertilizer.  You can use them as mulch or as a green ingredient in the compost pile….  Organic gardeners know that earthworms are essential to a healthy garden.  When it comes to improving soil structure and water-holding capacity, earthworms can’t be beat….  While earthworms will eat most any organic matter, coffee grounds are like earthworm candy.”

But here’s the best part for rosarians.  The article goes on to say that Sunset magazine sent a batch of Starbucks coffee grounds to a soil and plant laboratory in Washington State for analysis.  Turns out that the pH of Starbucks grounds is a slightly acidic 6.2, which is right in the middle of the pH range we’re shooting for in growing roses. And that’s not all: they’re also a slow-release fertilizer with 2.28% nitrogen, .06% phosphorus and .6% potassium.

The trick in using coffee grounds is getting hold of a lot of them.  Unless you only have one or two roses in your garden, the grounds from your home coffee maker just won’t cut it.  Fortunately, that’s not a problem.  Starbucks has a policy to recycle their coffee grounds, whenever they can.  So you can walk into any Starbucks, get a really good cup of Joe, ask whether they have any grounds available for your garden, and walk out with a 30-pound bag of fresh grounds.  I recommend going around mid-morning, because they’re just past their biggest rush of the day, have a lot of fresh grounds all bagged up, and aren’t too busy to pack them up for you.  Once the Starbucks folks know you want them, they’re happy to give them to you.  To put this in perspective, I have put several hundred pounds of grounds in my mulch pile over the winter.  That mulch will be going on my roses all summer and when I mound my roses for winter protection in the fall, a substantial proportion of the mulch I use will be composted coffee grounds.

I also use fresh grounds as part of my regular fertilizing regimen.  I mix the Twin Cities Rose Club's great organic “Bob’s Mix” fertilizer with wet, fresh grounds, right out of the bag, in a 50/50 ratio, putting about two or three big scoops of the fertilizer-grounds mixture on every plant.  One other benefit:  It makes “Bob’s Mix” smell better!  And the roses love it.

There’s more in the “American Rose” article, as well, such as how coffee grounds repel slugs.  I put them directly into my hosta bed last summer and didn't see any more slugs, so I think that works too.  In short, coffee grounds are an excellent all-around component in an organic gardening regimen and they are very available to all gardeners, so it’s a real shame to see them go into the trash.

Springtime is a great time to get started putting coffee grounds in your mulch pile and directly on your plants as they're getting started for the season.  So get on down to your local coffee shop, tell them you're a rose gardener and ask them for a big bag of grounds.  Your roses will act like they're highly caffeinated!

Jack Falker

March 17, 2013

Roses in Winter

The Lake Harriet Rose Garden is on the shore of one of our four beautiful lakes in Minneapolis (which means "City of Lakes").  Sunday, March 3rd was a beautiful sunny day, right at about 32 degrees Fahrenheit, so I put on my sunscreen and took a stroll through the rose garden and out onto the ice.  The lake and garden are about five miles from my house and about four miles from downtown Minneapolis in a very nice residential area known as South Minneapolis. Here's how it looks in Minneapolis at the beginning of March.

Here's the entrance to the garden.

Looking across the garden out toward the lake

The garden is using construction blankets to cover the beds for the first time this year.  They have always used mulch and leaves.

High Noon!

The garden sundial is one of my favorite places in the garden.  I take it's advice at this time of  year!

Out on the ice looking back at the bandshell and the Minneapolis skyline.  Downtown is about four miles to the northeast.

A family on the ice with their dogs.  The ice is about two feet thick and perfectly safe for walking around, fishing or whatever.

A nordic skier enjoying the sunshine.  The rose garden is on the far shore.

Here's the inside of the band-shell looking out at the lake.  We have great band concerts and lots of other interesting things here in the summer.

Hundreds of people were out running, walking, skiing, bike riding and generally enjoying themselves in the sun on this beautiful Sunday afternoon.

Got Castile Soap?

After publishing my last post on spraying non-toxic stuff, instead of the usual fungicides and pesticides, I was reminded by my good friends, Diane and Dick Lawson that they are spraying almost exclusively Castile soap on their garden (which is one of the nicest in the Twin Cities).
Here's the address of my last post:  http://theminnesotarosegardener.blogspot.com/2013/02/hazardous-roses-3-spray-nothing-toxic.html

I asked Diane, a recently retired high school physics teacher, to explain exactly what Castile soap is vs. the liquid dishwashing soap I've been using and was recommending in my article.  I was surprised when Diane told me that Castile soap is made primarily from olive and other vegetable oils, which presumably leave a beneficial coating on the plants, vs. detergent soap.  In other words, Castile soap is a natural surfactant that remains on the surface of the leaves, much as a surfactant fungicide might, as well as acting as a deterrent to insects.

I remember using Diane and Dick's Castile formula on my garden a few years ago and that was the summer I saw virtually no thrips or aphids.  Diane would contend that's the case in her garden every year.

Until now, my problem with using Castile soap has been the laborious preparation.  They use "Kirk's" Castile soap in bars, which has to be dissolved in water and then mixed into your sprayer.  Their procedure is to dissolve half a bar of Kirk's in a gallon of water and then mix one cup of that soap mixture into each gallon of spray mixture.  For example, for five gallons of soap spray, you would use five cups of the Kirk's/water mixture.

After talking to Diane the other night and remembering that I didn't enjoy dissolving bars of soap in water, I "Googled" Castile soap to better understand it and here is what I found:
http://en.wikipedia.org/wiki/Castile_soap (which includes a picture of a bar of Kirk's).

I also found this story about making your own Castile insecticidal soap: http://www.ehow.com/how_5791479_use-dr_-bronners-insecticidal-soap.html

If you Google: "Castile soap insecticide" you will find several other articles, as well

I also found that Target sells Dr. Bronner's Castile soap in liquid form, so that means you don't have to dissolve bars of soap in water to use it.  Here is the Target shopping site for Castile soap:
http://www.target.com/p/dr-bronner-s-pure-castile-soap-lavender-32-oz/-/A-10770138?reco=Rec|pdp|10770138|TargetClickEV|item_page.vertical_1&lnk=Rec|pdp|TargetClickEV|item_page.vertical_1

I enlarged the label of Dr. Bronner's Castile Soap and here are the ingredients: Organic coconut and olive oils, organic hemp oil, organic jojoba oil, lavandin extract, organic lavender oil, citric acid, and vitamin E.  Now that sounds like something I wouldn't mind spraying on my roses and, if I happen to get some on me, I'll just lather up and wash it off!

I believe that adding baking soda to the Castile soap mixture at a rate of 3 TBP per gallon would probably make it a better fungicide, as well.

You could also substitute 2 TBP of Castile soap for the dishwashing detergent in the cider vinegar/aspirin, soap mixture I recommended in my last post: http://jack-rosarian.blogspot.com/2013/02/hazardous-roses-3-spray-nothing-toxic.html .

As soon as this year's new growth starts around here, I plan on spraying a Castile soap mixture early-on, and I'll let you know how it works.

Jack Falker (jack@falkerinvestments.com)
03.01.2013