Oopsies

Well, I'll start off year two of my blog by showing you a recent little oopsie that constitutes my biggest garden error; EVER, bar none!  This little mistake was not on the same level as placing a Stella de Oro daylily next to a magenta phlox.  Nor was it quite equivalent to planting Houttuynia cordata 'Chameleon' between the stepping stones of a walkway (although that would be a pretty big error).  No, this bonehead move resulted in horticultural murder, mayhem, and genocide in my garden.  I may need to convene a Gardener's War Crime Tribunal to clear up this aftermath and assign blame.

Before I confess, I must, in my defense, state the mitigating circumstances.  It was a hot Saturday.  A very very hot Saturday.  And I had been working in the garden for several hours, and likely was operating under delirium brought on by heat stroke.  And there were several things left to accomplish on my list before I melted away, including mixing up "Over-The-Top" spray to kill some grass invading an heirloom group of irises and my strawberry bed, and I was in a hurry.   So I reached for the Hi-Yield Grass Killer sitting benignly on my killing shelf (as Helen Dillon refers to it), measured out the proper amount, added some sticker-spreader, and sprayed the aforementioned areas.  And with a little left over, decided to also spray some Nut Sedge (Cyperus rotundus) that had surrounded a 'Jean Kenneally' miniature rose and some crabgrass that was romping across an island bed.

Alas, about 45 minutes later it occurred to me suddenly that I had picked up the identically shaped and sized bottle of all-purpose herbicide that I used on the buffalograss this spring. Oops.  A quick check of the label indicated that this herbicide took two hours to become rain-proof, so I made a frantic run for the hoses and quickly washed off what I could.  The only hope that I really had is that in many areas of the strawberry patch I had directed the spray only on plants choked by grass and had not generally sprayed the entire bed.  The end result is that the strawberries mostly survived, I can't bear to show you the irises, and I can only bear to show you the miniature rose.  If you peer closely at the picture at the left, you'll see that the green foliage at the bottom of the picture, taken 3 weeks after the mishap, is a surviving part of the rose.  Thank God this rose was own-root and several years old because it has a chance to recover someday. 

There are a couple of lessons here.  First, the old adage about never to "ass-u-me" anything because it makes an ass out of -u and -me applies here.  Just because I knew the bottle shape and size didn't excuse the fact that I should have checked the label.  Second, my practice of writing the concentration in bold marker on the bottle so that I don't have to search the label for it may not, after all, be a good thing.  If I had to go looking for the fine print, I might just have noticed that what I was holding wasn't what it should have been.

I've been thinking about trying to host a monthly "show your garden errors" blog day.  What do you think?  Would a display of public humility either be educational or cathartic for you?  Do you think that all of you out there with perfect gardens would find enough problems and  be willing to disclose them to make it worthwhile?  Or did I just act out the horticultural equivalent of Will Ferrell in the movie "Old School," streaking along by myself and expecting the gang to follow?

Corn Gluten Hub-bub-i-cide

Since the 1990's, corn gluten meal (CGM) has taken the gardening world by storm.  CGM is the protein by-product of milling corn, and this high-nitrogen compound was discovered by researchers at Iowa State University to be an effective pre-emergent herbicide, reducing seed germination by inhibiting root development.  Organic gardening and farming communities have quickly adopted this natural miracle substance as a method of weed control.

Continued research, however, is showing that CGM is, in fact, far from a natural cures-all for organic gardening.  It does not adversely affect existing weeds.  To the contrary, the nitrogen in CGM (about 10%) benefits existing weeds as much as the desired plants we're trying to help.  It's not a selective product, nor is it effective as a pre-emergent against all weeds.  Most importantly, it is failing to reach an important milestone to recommend its continued use; it seems unable to make the leap from greenhouse to the field.  While greenhouse trials demonstrated efficacy, field trials in the same locations have been unsuccessful.  Washington State University and Iowa State researchers found no differences in weed control on field-grown strawberries using CGM.  Researchers in California found that the use of mulch alone in containerized plants was more effective in controlling weeds than CGM.  California and Oregon researchers found no control of turf grass weeds by CGM, although the turf itself responded to the nitrogen in the CGM. The truth is that moisture, light, and warmth all affect seed germination and these factors are all much harder to control in natural environments than in the laboratory. Since CGM inhibits seed germination primarily by desiccating soil and denying moisture to seeds, it's no wonder that it does not work well in areas of the country with abundant moisture in the spring (most of America).  Linda Chalker-Scott, in The Informed Gardener Blooms Again, concludes that corn gluten meal may act adequately as a pre-emergent herbicide in the Midwestern US, but that it's not effective for western climates or for climates with abundant pre-spring moisture.

There are many lessons in the continuing saga of CGM. I've seen the step from laboratory efficacy to field efficacy fail often in pharmaceutical trials and surgical procedure trials in my chosen profession of veterinary medicine.  There are a couple of hidden messages here to gardeners as well, though:  First, organic gardening principles are great in theory, but it's obvious that weeding is so much of a chore that even organic gardeners will seize on any chance to reduce the work involved. So just who is kidding who?  Second, just because a substance is natural does not mean it's a miracle cure or that it is economical to use. We're going to be driving the price of corn high enough with all our driving around on the ethanol we derive from corn; we shouldn't throw our gardening budgets out of whack by using up even more corn as a partially-effective pre-emergent herbicide.  And if it is not useful as a herbicide, but we use it anyway as an organic fertilizer, somebody out there had better be doing some calculation on whether we use more inorganic fertilizer on Iowa and other Midwestern fields to grow the corn for a bag of CGM than the bag of CGM provides us back as organic fertilizer.  As the grandson of Indiana crop farmers, I guarantee you that no dirt farmer is growing 200 bushel/acre field corn without artificial nitrogen and herbicides.  Is CGM really "organic" or is it organized hype?