Bindweed Barrier


One of the scourges of my garden, besides flea beetles and cucumber beetles, is bindweed, convulvis arvensis, or wild perennial morning glory.

Actually, it’s not a scourge in this garden yet, but I have worked gardens over the years in which it was rampant, and it has started making inroads from the conventionally farmed fields in the valley below me.  I don’t know how many years it has taken it to make its twisting way up the hill, but last year it began creeping out from the southern border.

Bindweed is pernicious–its roots are deep and complex and worm their way through the soil at an amazing rate.  On the surface, bindweed’s foliage twines around anything within reach, choking it out and dragging it down with its weight.

Then, it flowers a sweet, innocent little white saucer tinged with pink, and it sets a seed with a seedcoat so hard it can survive fire, drought, pretty much anything.

Convulvis arvensis likes compacted and/or clay soil, so my line of defense between the lower garden where it has taken hold and the upper garden that is mostly clear of it, is to dig a fluffy-soiled trench-like bed in between.

I spent yesterday afternoon, between grading papers, working up this bed to the depth of about a foot or more, and using the broadfork to get deeper than that.  I pulled out every one of the white, hairlike roots I could find and threw them back down into the sacrificial area below.

Last year this barrier bed grew carrots.  This year maybe broccoli–I haven’t decided yet.  I’ll ring the bed with a thick layer of wheat straw mulch, and when we till that bottom area, I’ll seed it thickly with buckwheat to shade out the bindweed’s comeback.

One of the worst problems with the bindweed is that every piece of root that is broken up by tillage or cultivation or any kind will sprout into a new plant.  Technically it is possible to till it to death by breaking it up into smaller and smaller pieces, until the plants are exhausted–but some of those roots go very deep, and I would expect a re-emergence within a year or two.  Trying to till it to death is a major commitment–if you miss a tilling, you’ll have made the problem much, much worse than it was.

Solarizing mulches don’t kill it because the main roots go too far down.  The organic herbicides based on acetic acid (vinegar) also do not harm the roots–they just kill off the tops.  But, mulching and shading do control the spread somewhat (at least above-ground).

Really, the best thing I’ve found is to work the soil deep and keep it as loose as possible (not an easy feat in our clay county).  Mulching and amending the soil tend to keep rain compaction to a minimum and heighten the organic matter  and fluffiness of the soil–making vegetable plants happy and bindweed unhappy.

Over the years I have pulled so my hands-full of this weed I would see its image when I closed my eyes at night.  When I see it now in the gardens, I immediately set myself up for an epic battle-of-the-bindweed, and begin plotting my strategy.

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One response to this post.

  1. Posted by Middle Man on April 11, 2008 at 7:20 am

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