Thursday, June 19, 2014

Of Poppies, Snow, & Herbicides

Oriental poppies, now in bloom with large, floppy, flaming red blossoms, are worth ooh-ing and ah-ing about. Likewise for Snow in Summer (Cerastium tomentosum), with small gray-green leaves and small white flowers, except that too few people know or grow this plant.  Here, the two plants look especially congenial together with Snow in Summer hugging the ground at the feet of the poppies and spilling over the rock wall that supports the bed in which these plants grow.

No skill is needed to grow Snow in Summer, or to propagate it. Plant it and it will spread, rooting as it creeps but never with frightening speed.

Alas, the show from either plant is all too transient. Poppy foliage is soon to yellow and melt slowly back into the ground. And by the time you read this, blossoms of Snow in Summer will have tapered off and its leaves will have lost their exuberance of spring. The show’s transience makes it all the more appreciated.

A narrow, yellow strip of vegetation -- dead vegetation --  sits at the bottom of the rock wall supporting the poppy and Snow in Summer bed (also home to espaliered pears, rugose rose, alliums, and other perennials) and at the its upper border with lawn. I can’t say that I’m proud of the yellowing strips of lawn and weeds, but the weedkiller I applied is very effective at keeping errant weeds and grass out of beds, paths, from climbing the rock wall and growing in between bricks of my terrace, and away from the bases of young trees. Weedkiller??!!

Yes, I am spraying weedkiller . . . but the weedkiller I’m spraying is very benign. I take straight household vinegar, which is 5 to 6 percent acetic acid, and add to it, per gallon, 2 tablespoons of canola oil and 1 tablespoon of dish detergent. The detergent and oil help the vinegar spread out on and stick to the leaves.

The USDA also has been researching the use of acetic acid as an organic spray to control weeds. They found 20 percent acetic acid to be very effective, which is not surprising. Twenty percent acetic acid, though, is neither very safe to use nor readily available.

My vinegar concoction, at 5 to 6 percent acetic acid, is, of course, not as effective as the USDA’s 20 percent. Nor is it nearly as effective as the widely used chemical weedkiller Roundup. My mix only kills green leaves; Roundup is translocated throughout a plant to kill roots, stems, and leaves. Plants store energy in roots and stems so can recover from my spray to grow new leaves. Eventually, with repeated spraying, vinegar-sprayed weeds run out of energy and die. Plus, my mix is not much different from salad dressing (except that it would need more oil, some herbs, and no detergent).

My aim is to spray frequently enough to kill each emerging round of greenery while it’s still drawing on energy reserves, before the leaves start socking away excess energy in roots and stems. Early in the season weekly sprays are needed; later, every two weeks or so.

Because vinegar only kills greenery by direct hit, it is most effective on smaller weeds where there is no “shadow effect.” The vinegar spray’s effectiveness drops at temperatures below 70° F.

My farmden necessitates the application of about 8 gallons of vinegar mix per session, most easily applied using a backpack sprayer. Mixing up and spraying the mix is no fun but has become less unenjoyable with my new Jatco sprayer.

Anyone who has used a backpack sprayer will appreciate Jatco’s rather unique qualities: a carrying handle, clips for holding the pumping lever and spray wand during storage or carrying, a large mouth for easy filling and cleaning, a mixing paddle that moves with each pump of the handle, and the totally internal pump that eliminates that awful sensation of spray material dripping down your lower back (even if it is just vinegar). The sprayer is almost perfect, two very minor shortcomings being the difficult-to-read volume indicator embossed on the tank and the lack of a bottom handle to grab when inverting the sprayer when cleaning it.

The best thing about the Jatco sprayer is the good leverage afforded by the way the pump handle is connected to the pump. Less pumping means less work. Carrying 3 or 4 gallons of liquid on your back in the hot sun is work enough.


  1. What a beautiful combination! I may have to move some of my snow in summer to the edge where my Poppies grow - copying the sincerest form of flattery? My poppies are finished blooming (and so is the snow in summer but still love its silvery foliage!) I use vinegar in sidewalk cracks but also found a product consisting mainly of cinnamon bark - I'm not brain enough to know the chemical properties - but it sure worked well on the crab grass in my driveway. Also recommended to use at temperatures around and above 70. I don't spray enough to warrant the Jatco but sure sounds like an ideal delivery method!

    1. Although the snow-in-summer is no longer at its best, the poppies still look great. Not oriental poppies though. Shirley poppies, I merely sprinkled the seed on the bed in March and now the bed is bursting with the flaming red color of Shirley poppies.

      I prefer the vinegar to kill weeds because it's cheaper.

  2. I have a problem with bindweed. I think it got introduced with the cow manure I got from a neighbor. (I need to learn hot composting). I have a vegetable garden with raised beds and I mulched the paths with old hay six inches thick. The bindweed is growing up through it. I've been trying to keep it pulled to kill it off (eventually) but spraying it might be easier. Don't want to introduce roundup to my garden but I'm wondering if there are any lingering effects of the vinegar. If I douse the hay with it to get the bindweed and then (for example) put the hay on the compost pile - any problem with all that vinegar? Just found your site and videos - great inspiration! Thanks.

    1. I also have a problem with bindweed -- this year, at least. I had the problem a few years ago, got rid of it, and now it's back. Mostly, I just religiously go throughout the garden regularly and pull the plants. Vinegar does burn them but pulling might be easier.

      Vinegar is not at all harmful, especially in the amounts used for spraying. Acetic acid is a natural chemical that breaks down over time.

    2. Lee,

      Bindweed will regenerate from pieces of root. Given that the root system is extensive, there's a pretty good chance that weeding will break roots. If you are going to go through the garden and pull the plants, why not go through the garden and surgically apply a systemic weed killer. I'm opposed to using Roundup but we do use it surgically to get rid of plants that regenerate from bits of root. We paint it on the leaves of horseradish wherever they pop up. We inject it into the stumps of sumac and Manitoba maple, We paint the leaves of Vinca major.


    3. True, bindweed will regenerate from root pieces unavoidably left in the ground. But bindweed, like any plant, will eventually die if the tops are frequently and regularly removed. No top = no photosynthesis = death.The chosen approach depends on how much bindweed there is, how much you like to pull the vines, and how much you have an aversion to Roundup. In my situation, pulling is effective and not overly tedious.