Uncovering Your Roses and When to Prune

When to uncover your roses in the Spring is really quite easy to determine if you remember the reason for covering them in the first place.  That is, to keep them from freezing and thawing repeatedly over the winter months, which is what kills them.  In the Upper Midwest, where I live, we finish covering our roses at the point when the ground freezes and it is our objective to keep them frozen all winter.  Let me repeat that: In the Upper Midwest, we don't cover our roses to stop them from freezing; we cover them to keep them frozen.  Every method of winter protection in this climate, including the Minnesota Tip, has that same objective, and I am always surprised when people don't understand that.  Our ground freezes generally at least two feet down and sometimes, as in the winter of 2013-14, it freezes down as much as four feet.  So it shouldn't be hard to understand that everything planted at the surface freezes, regardless of how you insulate.

For folks in warmer areas, like the warmer parts of zone 6 and throughout zone 7, where the ground freezes down a few inches and then repeatedly thaws and refreezes throughout the winter, the purpose of winter cover would be the same, i.e. to keep the roses from repeatedly freezing and thawing, but in this case it would be to insulate them to prevent them from freezing in the first place.  It really amounts to the same thing,  however.

Given these principles, when to uncover your roses should be obvious, wherever you live.  It is simply when the danger of freezing and thawing has passed.  Around here, that usually occurs sometime in the first two weeks of April but virtually never in March, regardless how warm it might get for a few days.  Let me give you a recent example.  In the spring of 2012 we had 70 and 80 degree weather in mid-March causing fruit trees to blossom etc., but in the next week we had 10 degree weather followed by at least two weeks of below freezing weather.  This caused the loss of almost the entire apple crop in Minnesota and Wisconsin and virtually the entire cherry crop in western Michigan.  If you had uncovered your roses in March 2012, thereby allowing them to thaw out, you would have suffered severe damage when they froze again.

I realize that it is very tempting to uncover your roses when it first warms up in the spring.  If you use the leaf bag method, which I have advocated in my blogs, you can choose to partially uncover your roses by rolling the leaf bags back but leaving them ready to replace, if the weather turns cold again.  This approach allows the plants to begin thawing and to soak up spring rains, while keeping your options open for easy recovering.  I would say that I use some form of this approach almost every year, especially when it starts to rain (vs snow!).

Today, April 1st, it was 82 degrees and we are expecting thunderstorms tonight so I decided to go out and roll the bags off my roses, while keeping them close-by, if I have to roll them back

Wherever you live, my suggestion is to watch the seven-day weather forecasts in early April and try to determine when your nights stay consistently above 25 F (-4 C).  If you keep the mounds around your plants, even if you pull the bags back, temps down to 25 F will not refreeze your plants.  If you are in doubt, just keep your plants covered until mid-April, around here.  It won't hurt them.

And here's a quote from Paul Douglas' weather blog today:

"Another Relapse After a May-like temperature swoon today temperatures cool off later this week, a taste of early March shaping up for early next week with readings struggling to reach 40F Monday and Tuesday. European guidance is even hinting at a rain/snow mix, especially north of the Twin Cities. Don't rule out more slush before the daffodils arrive."

On the theory that a picture is worth a thousand words, here is how my beds look after rolling back the leaf bags this afternoon.  Note that the roses still have plenty of leaves and mulch around them and the bags are right there if I want to roll them back over the plants. Incidentally, most of those leaves around the plants will get pushed back in the bags and be transported to my compost pile, when it's time to finally uncover the beds, which will probably be in 10 to 14 days, when Paul Douglas is no longer warning about slush and freezing temps.

Pruning
I always laugh when I hear someone say you should prune your roses when the forsythia blooms. Suppose it had bloomed in mid-March 2012, as mentioned above, when your roses were still covered?  When the forsythia blooms really has nothing to do with when you should prune your roses. Pruning for me is a two step process.  First, right after I uncover my roses (i.e. mid-April), I begin by cutting off all the dead wood, right down to where the canes begin turning green.  This is a very rough, quick cut that I do with my battery-powered Black & Decker hedge trimmer.  I don' t worry about rough cuts on the canes because I know I'm coming back later to make my final pruning and shaping cut.  All I want to do is to take off the "overhead" of dead wood to clear the way for new growth that will come from the green canes.  Once I can see that nodes on the green canes are starting to swell, in anticipation of setting new leaves, then I begin my second cuts to shape the plants and eliminate any weak, wispy growth from last year.

So, in summary, you should first cut off all the "overhead" dead wood and then, when the plants show signs of growing, make your second cut and seal it off to stop saw-fly wasps from burrowing into the fresh wood to lay eggs.  I use Elmer's school glue for my sealant, which works very well and is quite inexpensive.  And the forsythia may or may not have bloomed when you finish.  We're talking roses here, not flowering shrubs!

Jack Falker
April 1, 2015

Climate Change Is More Extreme Up North

Readers of of my December 2014 blog: "How Winters Are Changing":
( http://theminnesotarosegardener.blogspot.com/2014/12/how-winters-are-changing.html )
will recall that national climatology statistics clearly show that climate change is more pronounced in the northern latitudes and, in particular, Minnesota.  My 53-year Extreme Minimum Temperature (EMT) trend lines (1962-2014 inclusive) statistically predict that the Twin Cities area will consistently be in USDA Zone 6 (where St. Louis, Detroit and Louisville used to be), within the next seven or eight years.  In fact, the EMT recorded in early January for the winter of 2015 was -11 F, which is above the trend line and within one degree of Zone 6.  In fact, most of our winters since the year 2000 have been in Zone 5, with only three in Zone 4, including last year, which was an anomaly all over the northern states.  Yet, the USDA persists in rating the Twin Cities in Zone 4, based on 2005 data, now 10 years out of date.  Close enough for government work?  Not in my book!

This week, Minnesota Public Radio published a special report on the phenomenon of northern climate change with the article: "Climate Change in Minnesota: 23 Signs". And even though many of my readers don't live in Minnesota, or even in the United States, this makes very interesting reading. I will conclude with a sentence that I have written repeatedly:

"You might argue why it’s warmer in Minnesota these days, but you can’t deny the fact that it is warmer, and that has important implications for Northern Gardeners."

Here's that excellent Minnesota Public Radio article; enjoy and let me know what you think:

http://www.mprnews.org/story/2015/02/02/climate-change-primer

Jack Falker
February 2015
jrfalkersr@gmail.com

Composting in Winter

Composting isn't just for warm weather.  It can be a year-round activity, which, in the winter months, allows you to compost "green" kitchen scraps and lots of coffee grounds for use on your roses in the spring. Even here in Minnesota, where the ground usually freezes hard and deep in winter, compost piles will generally remain mostly unfrozen beneath the snow because of the heat generated in the decomposition process.  If you dig through the snow and open up holes in the pile, you can keep adding to it all winter.  But that hasn't been necessary here this winter, as you can see in the picture below.  Our low temperature in January was -11 f., which puts us almost in USDA Zone 6.  We had a lot of days above freezing in late December and throughout January, and what little snow we had is just about gone.

As usual, some folks in Minnesota go to extremes.  I heard a funny story in mid-November, when it was actually much colder and snowier than was in December and January.  Someone, here in Minneapolis, had moved their composting operation into their basement for the winter, in one of those fancy (and expensive) rotating drums. I guess I was kind of incredulous and asked what they were going to do with it in the basement.  The guy was kind of put out when I asked him why they just didn't leave it outside to compost naturally.  I really can't imagine having that decomposition process going on in my basement.  I just make a pile outside, where everything happens naturally, and the earthworms have a field day, leaving their castings (down deep where it's warm), year-round.

Today, I dumped about 200 lb. of Starbucks coffee grounds in my pile, along with lots of green kitchen scraps. When I opened up the pile, a cloud of steam puffed out; proof positive that the composting process is alive and well in mid-winter.  Here's how it looked, after I finished pulling the shredded oak leaves back on top.  Note the lack of snow and the two Christmas trees behind the pile doing double duty as a habitat for birds and other winter critters.  The white stake in the foreground is a terminal post for my electric fence, which comes up from underground at that point for use in the summer.  The small white stakes to the left, in the little bit of snow that's left, mark spots where I have seeded pollinating plants for stratification over the winter. This area around my mulch pile is one of several insectaries, designed to attract bees and other beneficial insects to my rose gardens. (See http://theminnesotarosegardener.blogspot.com/2014/12/bugs-and-roses.html ).

Don't "Sweat" the Wind-Chill on Your Roses!

Tonight is likely to be the coldest night of winter 2015, in the Twin Cities.  Temperatures are predicted to fall to -13 F (-25 C) at Minneapolis-St. Paul Airport, which, in the context of winter history in Minnesota, is  no big deal (It's 0 F  [-18 C]  right now at 9 PM). That will put us in the upper reaches of USDA Zone 5 for the year, i.e. approaching Zone 6, when the USDA still has us listed in Zone 4 (incorrect in my opinion).

Author's note: The actual low temperature recorded on the night mentioned above (January 6, 2015) was -11 F, which should be the extreme minimum temperature (EMT) for 2015.  This puts the Twin Cities (MSP) just one degree shy of a USDA Zone 6 winter in 2015. 

But to listen to the apoplectic, Twin Cities TV weather folks creating "shock and awe" among their listeners, the real news is that wind-chills are going to reach a "dangerous" -30 to -35 F (-34 to -37 C) by tomorrow morning.  By doing this every day in the winter, they have created the idea among a very large number of people that temperatures are much colder than they really are.  In point of fact, wind-chill is only relevant to the cooling of the exposed flesh of warm-blooded animals (with no fur like us, unless you grow a beard). It has nothing to do with the temperature of cars or houses or, most importantly, plants, which in our case means ROSES! (For a full explanation of the effects of windchill on roses, see the quotes below from my wind-chill blog of last January).

Looking at it another way, if you're foolish enough to run around outside in your birthday-suit tomorrow morning in Minneapolis you're going to freeze your "you-know-what" off in the "relative" -30 to -35 F wind-chill, because of the effect of the cold temperatures on your exposed flesh, plus the wind which doesn't allow your body to warm itself. But if you dress warmly with a coat, hat, gloves, ear-protection and maybe a scarf over your nose, you have nothing to worry about, except the real ambient temperature of -13, which is cold enough, without trying to make it sound worse.

Here a couple of images of one of my Buck Earthsong beds taken last year at this time, when we had a lot more snow than we have now, which was a good thing then:

And here are several quotes from my article "How Windchill Affects Roses" from last year at this time:

First, from a National Weather Service article:

"Wind chill is the term used to describe the rate of heat loss on the human body resulting from the combined effect of low temperature and wind.  As winds increase, heat is carried away from the body at a faster rate, driving down both the skin temperature and eventually the internal body temperature.  While exposure to low wind chills can be life threatening to both humans and animals alike, the only effect that wind chill has on inanimate objects, such as vehicles, is that it shortens the time that it takes the object to cool to the actual air temperature (it cannot cool the object down below that temperature)."

And from a Kansas State University article:

Plants Don’t Care if the Wind Chill Tanks

"When wind chill temperatures plummet, gardeners chafe about their landscape and fruit plants' odds for survival.  Some gardeners worry too much.... Cold can be a killer if people are growing marginally hardy plants or if air temperatures drop well below what's usual where they live.  Hard freezes are particularly destructive when plants aren't fully dormant.  But cold and wind chill aren't the same thing.  Wind chill only affects warm-blooded animals -- including people.  It's an indexed, scientific measure of how wind speed and air temperature combine to impact animal heat loss.... We know, for example, that our heat-loss rate will speed up as the air temperature drops.  The faster the wind is blowing, however, the more dramatic that heat loss is going to be .... Wind chill has no meaning for plants.  Unlike warm-blooded animals, they don't try to maintain a particular body temperature year-round".

And another:

"Of course, we know that  roses feel the winter cold and die back according to the level of protection afforded them.  And winter-winds do, of course, have an effect on that die-back, desiccating the canes, but the important thing to understand is that wind does not make a plant "feel" colder than the actual temperature, even though it shortens the time it takes for the plant to reach that temperature.

And this one is important:

Here's an example: Suppose that the ambient temperature is 35 F and the wind is blowing 30 MPH. According to an NWS  chart, the wind chill is 22 F.  So are your roses freezing?  Or, better yet, are the puddles in your garden freezing?  Of course not, because the freezing point of water is 32 F.  However, if you go out in your garden without a hat and jacket, you will feel like it is 22, not 35, because of the combined effects of the cold temperature and the high wind on your flesh."

And here's that whole article from last January:

http://theminnesotarosegardener.blogspot.com/2014/01/how-windchill-affects-roses.html

Let me know if you have any questions.  I'll be safely bundled up tomorrow morning when I go outside.

Jack Falker
@mnrosegardener
jack@falkerinvestments.com
01/06/2014

How Winters Are Changing

Climate Central (CC), an independent organization that surveys and conducts research on climate change, recently published a series of  maps showing the relative extent of climate change in all regions of the United States. What's most notable about these maps is that the northern tier of states has experienced the most winter-warming since 1970, and that the upper-midwest, especially Minnesota, has warmed more than the any other area. Here's that article:

http://www.climatecentral.org/news/winter-climate-trends-18409

What really jumped out at me when I saw CC's maps was that they show exactly (and not surprisingly) what my own trend-line graphs of Extreme Minimum Temperatures (EMT) indicate, which is (1) that the whole northern tier of states has gotten significantly warmer and (2) that the further north you go the sharper the change.  The difference between CC's work and mine is that the Minnesota  Rose Gardener graphs cover a longer period, i.e. since 1962 vs.1970, and that my graphs are dynamic, in that the trend lines, being statistically valid, are predictive of the future.

Here is CC's map of the United States:



Note that the upper-midwest generally has warmed more than the rest of the country and that the areas around and just north of the Twin Cities, and in the northwest corner of Minnesota, have warmed more than just about anywhere else in the country (my upstate NY and New Hampshire readers will be happy to note they are paralleling the upper-midwest).

This is very clear when you look at my 53 year EMT trend-line graph for the Twin Cities.  Note the relatively sharp slope of the line and how it points upwards to USDA Zone 6.  I will show several other cities' EMT graphs below, which show definite warming, but with shallower trend lines than Minnesota, just as the CC map shows.



Here is a regional close-up of the upper-midwest from CC's article:

And now let's look at the EMT chart for Milwaukee to see the difference in the slope of their warming trend-line:

Note that the slope of the trend-line, while definitely upward, is not quite as sharp as the Twin Cities' line and, while they've had two winters solidly in USDA Zone 7 in this decade, the line predicts that it will be quite a few years before they move into Zone 7.

Here is Detroit, which has now crossed into Zone 7, as predicted by the trend line, albeit with a very shallow slope over quite a few years.

Here is CC's regional close-up of the Ohio Valley:

And here is my EMT graph of St. Louis, which has moved solidly into Zone 7, with a fairly sharp upward trend:

And here is Chicago, which perennially was in Zone 5 but now has moved solidly into Zone 6.  Note that the slope of its trend line is very similar to Milwaukee's, which should be no surprise, but they too are quite a long way from being consistently in Zone 7.

Finally, here is Indianapolis, which has a trend line a bit shallower than Chicago or Milwaukee, but the line projects that it is almost in Zone 7 (and actually had a Zone 8 winter in 2012).

So What Happened Last Winter?

That's a perfectly logical question, in the face of all the trend line evidence of warming.  Most climate scientists believe that the "polar vortex" phenomenon we experienced last year was (or is) a product of climate change and that it is unlikely to repeat itself with regularity.  However, that is certainly not to say that it won't happen again or that we might not see variations of it.  Note in the graphs above that last winter was a big departure from all trend lines, especially in some of the warmer midwest cities like Detroit, St. Louis and Indianapolis. With a developing El Nino, which is also a child of climate change, it seems unlikely that we could see another major vortex incursion in the winter of 2014-15.  For a more detailed explanation of the polar vortex and its presumed causes, please see my October 2014 blog: "Winter Protecting Roses in a Climate Change Environment".
http://jack-rosarian.blogspot.com/2014/10/winter-protecting-roses-in-climate.html .

Conclusion

Finally, I would like to emphasize the statistical validity of the trend-lines generated on the graphs in this article.  As mentioned earlier, these trends are both predictive and dynamic, in that you should be able to extend them into the future with a fair degree of accuracy, regardless of one year anomalies in either direction.  For example, it is logical to conclude that the Twin Cities will see more winters in Zone 6 than in Zone 4 in coming years and that, within the next seven or eight years we will see consistent Zone 6 winters.   This can be clearly seen on the St. Louis graph, as it progressed along its trend line to where it crossed into Zone 7.  And the same can be seen on the Detroit chart, although its change was more gradual and over more years.

Having said all of this, I am not implying that winter-protecting roses isn't important to prevent the inevitable freeze-thaw cycle.  Rather, I am saying that extreme measures, such as the Minnesota Tip, are unnecessary, if sensitive roses are properly planted with bud unions below ground.  Please see the article cited above, as well as my September 2013 article "Winter Protecting Your Roses" for more complete explanations:
http://jack-rosarian.blogspot.com/2013/09/winter-protecting-your-roses.html .


Jack Falker
@mnrosegardener
jack@falkerinvestments.com
December 2014

"Bugs and Roses"

This is part two of my July 2014 article "Controlling Spider Mites and Thrips on Roses Without Insecticides-- Part One".  In case you haven't seen it, here's that article:
http://theminnesotarosegardener.blogspot.com/2014/07/controlling-spider-mites-and-thrips-on.html

The underlying purpose of these two articles is to demonstrate that attracting, introducing and nurturing beneficial and predatory insects to control common pests like spider mites and thrips is both possible and desirable in a rose garden.  I finally realized, after many years of spraying everything from organophosphates like Orthene, neonicotinoids like imidicloprid (Merit) and pyrethroids like Demand CS (which is what I thought I was supposed to do to control everything from aphids to Japanese beetles), that what I was really doing was wiping out naturally occurring beneficial and predator insects.  For example, I suddenly realized that I no longer was seeing lady beetles and lacewings, which are natural predators for spider mites.  It's no wonder because, instead of tediously picking Japanese beetles off my plants and drowning them in soapy water, I sprayed them with Demand CS, which works really well, but also wipes out all other beetles (like lady bugs) and just about every other predatory insect in the garden.  As a result, I ended up with a massive infestation of aphids (something I hadn't seen in many years) because I had destroyed all their predators, in my efforts to deter Japanese beetles.

Then, early in 2014, my compatriot-rosarian Paul Zimmerman mentioned a new book by Jessica Walliser, "Attracting Beneficial Bugs to your Garden", which changed my way of thinking about controlling insect pests in my gardens.  Here's a link to that book, which is available both new and used on Amazon:
http://www.amazon.com/Attracting-Beneficial-Bugs-Your-Garden/dp/1604693886/ref=sr_1_1?ie=UTF8&qid=1417916500&sr=8-1&keywords=attracting+beneficial+bugs+to+your+garden

Well, after reading Jessica's book multiple times, I decided I had to try what she advocates, and I learned a lot.  First, the good news:  I was very successful in controlling thrips without insecticides all last summer and, as a direct result, beneficial insects, including honey bees, bumble bees, mason bees, syrphid flies, lacewings and predatory wasps have flourished, on their own.  Second, the relatively bad news: spider mites were harder to control than I thought, when I wrote my July article, above.

I washed my roses at least every other day and I just couldn't get rid of the spider mites altogether.  Just when I thought I had the upper hand (as I did in July when I wrote the article) they would come back, not to the extent where I would see a lot of webbing, but just to where they would appear on new growth. If you were to look with a magnifying glass at the wilted leaf just under the bud in the picture below, you would find just a thread or two of mite webbing.  So the wilted leaf is a tell-tale sign; something it has taken me a long time to understand.  Those leaves die and become "crispy", as the mites multiply and move on to other new growth. I was able to control the mites by cutting off that leaf stem and washing the plant, but they continued to pop up elsewhere on other new growth, no matter how much I washed.

I really didn't want to use a miticide because I had imported large quantities of predatory mites (at least 100,000 cucumeris and fallacis mites) from California and I wanted them to do their job on both the mites and thrips, before applying a miticide, which would likely take down most of the mites, including predators.  I made it until late August without using anything but water, but finally I had to do something because even my most resistant roses were succumbing to blackspot from the constant washing.  In August, I made one application of Floramite and that took care of the spider mites.  I won't know until spring if I killed all the predators (Fallacis mites are supposed to be hardy enough to overwinter in Minnesota) so we'll have to wait and see.  I'm not giving up on this, however.  Next spring I will start washing earlier and, if I can't control the mites with existing predators, such as lady beetles, which I didn't have in 2014, I will reintroduce more predatory mites.  I still believe it will work if I get enough predators on the plants

Thrips (both singular and plural, i.e., one insect is called a thrips)

Given the persistence of spider mites, I was pleasantly surprised to find that I was able to control thrips with the beneficials I was able to introduce and/or attract to my garden this summer.  Here's what a Carefree Beauty bud with thrips running around in it looked before my beneficials got to work.  By the way, any bud that looks like this gets plucked and disposed of someplace where the thrips can't fly back into the garden. That's the first line of defense when you're not spraying insecticides.

As long as you don't spray things that kill them, natural thrips predators, such as minute pirate bugs and syrphid flies are fairly easy to attract to the garden with plantings, such as oregano, yarrow, alyssum and cosmos.  And predatory mites can be imported from an insectary, such as Rincon-Vitova in California.  In talking to Jan Dietrick, who runs Rincon-Vitova, I also learned that beneficial nematodes released in the soil of each rose bed will feast on the pupa of thrips, eliminating something like 80% of them before they become active on the plants.  I ordered millions of the nematodes Jan recommended, as well as thousands of cucumeris predatory mites and 500 minute pirate bugs, in addition to 500 lady bugs for spider mite control. By the way, these beneficials aren't terribly expensive, compared with what I've been spending on insecticides.  However, the required overnight shipping is quite expensive so it's advisable to combine as much as you can in one shipment.  Here's Rincon-Vitova's website: http://www.rinconvitova.com/

I'm not sure exactly what did the trick on the thrips but, after they got off to a head start on me (see the picture above), I was able to control them from mid-summer onward.  I'm pretty confident that the nematodes were effective and I could see the syrphid flies, which arrived in droves, probing around in the flowers, so I believe the combination of those two worked.  The minute pirate bugs arrived too late to become well established, but I'm sure they will be around next summer, and I'm not sure about the predatory mites because they were too hard to see but I saw enough of them with my magnifying glass to know they were there.

Here's an interesting statement from an article on thrips by Applied Bio-Nomics,  the producer of the predatory mites I purchased from Rincon-Vitova:  "The first thing to know is that  I do not believe that  a single thrip has died from an insecticide registered against thrips for the past three 

 years  .... I will bet you that they died from the soap effect  of the spreaders and  the stickers rather than the active ingredients. So,don’t even think about using chemicals against thrips.... Another even more important reason not to use chemicals is because there is now considerable research that shows that sub-lethal chemical attacks actually induce the thrips to lay more eggs. "

You can find this article and several other equally interesting articles on Applied Bio-Nomics' website: http://www.appliedbio-nomics.com/

So, according to this expert, a chemical like Conserve SC (spinosad), the insecticide of choice for thrips, doesn't kill thrips, it just kills the beneficials like syrphid flies and minute pirate bugs that attack thrips.  This is completely opposite to what we have been taught to believe as gardeners.

Insectary Effects

Here's how a little insectary corner of one of my rose gardens looked last summer, with oregano, bachelor buttons, cosmos, dill, yarrow and a few other things to attract beneficials (Buck's Prairie Harvest is to the right).  When I took this picture, this little garden was teeming with wasps, bees and other beneficial insects that were nowhere to be found in my garden last year.  The idea of doing this, as well as directions on what to plant to attract various beneficials, came directly from Jessica Walliser's book, mentioned earlier.  I plan to expand my insectary efforts next year, which will include removing several more roses to make room for more beneficial bug-attracting plants.  In short, this really works!

Here's a picture of a bumble bee on one of my Earth Song plants last summer. I was really amazed at how many bees showed up in my gardens after I stopped spraying. 

Here's another bumble bee on one of the many sunflowers I planted last summer to attract beneficials.  I have no idea where all the varieties of bees (including many honey bees) came from but I did notice, with great interest, that the bumble bees were going in and out of a nest they had made alongside a drain pipe, just a few feet from where I had planted a stand of sunflowers to attract them.  No coincidence there!

One of the most important things Jessica Walliser talks about early in "Attracting Beneficial Bugs to Your Garden" is the need to be patient.  When there is a large infestation of insects like aphids or spider mites, it takes  time to build up enough predator mites and insects to feed on them.  I believe that's what my experience was with the spider mites this summer because I had killed off so many beneficial predators over the years, especially in my efforts to control an infestation of Japanese Beetles, which was especially bad in 2012.  I have written several articles about that effort, but I now recognize that the use of the pyrethroid, Demand CS, which is very effective in deterring the beetles, comes at the price of eliminating many beneficial insects (about which a knowledgeable rosarian from the TCRC, Sue Youngdahl, gently reminded me at the time). I'm not going to use it again in my garden, as well as other insecticides, with the possible exception of an occasional miticide, as I did this summer but would really like to have done without.  However, it is understandable that large public gardens and commercial growers do not have that luxury in their need to control Japanese beetles on a large scale, where picking them one at a time off the plants would be impossible (and those bugs are really awful and terribly destructive).  For example, I noted that the University of Minnesota Arboretum was using a pyrethroid in their rose gardens last summer, which is completely understandable.

What I achieved in one growing season was remarkable and these results have made me want to try even harder next year.  Nature is exceptionally responsive to our efforts to protect it, and my own most important lesson is that patience is everything, as we change our practices.  The rewards are well worth the inconvenience and extra effort.  I'll have more to say about  this as we go along, so stay tuned and feel free to ask questions.  We can learn together!

Jack

@mnrosegardener (Twitter)

jack@falkerinvestments.com

December 2014

Winter Protecting Roses in a Climate-Change Environment

Here is a PowerPoint presentation I made to the American Rose Society, North Central Division convention in the Wisconsin Dells on September 13th of this year.  Some of the presentation is a reprise of my March 2014 Blog: "What the Heck was Wrong with This Winter" https://theminnesotarosegardener.blogspot.com/2014/03/what-heck-is-wrong-with-this-winter_5.html and my September 2013 blog: "Winter Protecting Your Roses" https://theminnesotarosegardener.blogspot.com/2013/09/winter-protecting-your-roses.html

For the most part, the slides speak for themselves.  However, where explanation and comments are needed, I will fill in with some of the remarks I made during the presentation.

So here we go....

This is a picture I took of my nicely winter-protected Earth Song bed on Christmas Day 2013, right after we had received 8 inches of new snow cover, thereby providing the best natural winter protection of all.  Here in Minnesota, we seldom have to dream of a white Christmas!

But our winters are definitely getting warmer, as we shall see.

Below is my recently updated Minnesota climatology chart showing the Extreme Minimum Temperatures (EMT) for the last 53 years at MSP airport.  This is the statistic the USDA uses to determine the cold zones.  As you can see, the Twin Cities are no longer consistently in USDA Zone 4b.  As a matter of fact, there have only been three nights in Zone 4 in the Twin Cities, since 1999!  That hardly puts us in Zone 4 and, as you can see, the mathematically determined trend-line has an upward slope of about 25 radian degrees. If you project that trend-line off the right side of the chart, it would appear that the Twin Cities will begin to see more winters in zone 6 than in zone 4, within the next five years.

The most recent USDA charts were released in 2012, based on 1976-2005 data.  In other words, their data, prepared for them by Oregon State University, was already seven years old when they released it and is currently nine years old.  Those seven winters were some of the warmest ever recorded, which made the USDA data invalid when they released it.

Good enough for government work?  Not in my opinion.  We just have to think for ourselves, given the data shown below. 

Note that for all of the cities shown below the winter of 2013-2014 was unusually cold, pushing them down into zones that they had not seen in several years.  Cities like Chicago, Detroit, Indianapolis and St. Louis were especially hard hit, relative to the much warmer EMTs  to which they had become accustomed in recent years.  Look at Indianapolis, for example: the winter of 2012 had been zone 8 and 2013 had been zone 7, when the bottom fell out  in 2014, dropping them to zone 5.

This is a much bigger swing than the Twin Cities experienced and, even though we experienced a near record number of nights below zero in 2014, most of them were in zones 6 and 5; not a huge variance.

Milwaukee is rated at zone 5b, but they have had only five EMTs in zone 5 since 1999.  The rest of the years have been in zone 6 and zone 7; go figure.

Chicago, which was classified in zone 5 for many years, is now classified in zone 6, which is correct, but looking at the Milwaukee and Chicago maps together, it's hard to understand why Milwaukee, just a few miles north is not classified similarly, given the data of the last several years.  Looking at the slopes of their respective trend lines (Milwaukee's is steeper), both cities will likely see many winters in zone 7 over the next several years.

Look at Indianapolis: going from zone 8 in 2012, to zone 7 in 2013, to zone 5 in 2014; a big surprise for gardeners there, who aren't accustomed to extensive winter protection.

Detroit, which has perennially been in zone 6 ( I grew up and lived there until age 37, and can't remember anything colder than -10) has had eight winters in zone 7 and one in zone 8 since 1999. They've had only five winters in zone 5 in the last 53 years, and last winter was one of them.  This is a much bigger variance than seen in most other Midwest cities.  The only thing we ever did to our roses, when I was growing up, was to rake some leaves on the beds.  That sure didn't work last winter, when both Lakes Michigan and Huron froze all the way across.

Like Indianapolis, St. Louis' winters dropped two zones from 2012 to 2014; almost making it three zones to zone 5!  Suffice to say that no one there was ready for that to happen last winter.

What happened was an incursion of the "polar vortex" a phenomenon that had never been seen in the U.S. to the extent that it was in 2014. Note, in the two graphics below, that unusually warm air, both to the west and east of North America formed a "pincers" around the normal polar vortex, a cyclone of super-cold air rotating tens of thousands of feet above the north pole (south pole too) tipping it over into central Canada and the Midwest USA.  Note, in the second graphic below, that it also happened in China and eastern Siberia, which you would expect, but something that was not reported here.

Note that it was as warm in England and Western Europe (just to the right of Greenland on the great circle map below), on February 27th, as it was along the Gulf Coast of the United States; pretty amazing.

Be sure to also read my blog: "Winter Protecting Your Roses", written in September 2013:

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