Friday, September 27, 2013

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!







Tuesday, September 17, 2013

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






Saturday, September 14, 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: 

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!":

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: 




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











Thursday, September 5, 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






Thursday, August 15, 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



Saturday, June 1, 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:

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









Wednesday, May 1, 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?