Perennial sow thistle experiment
Posted: Wed Apr 05, 2006 9:30 pm
I've finally found time to post about an experiment I undertook over a year ago. I had been plagued by perennial sow thistle on my allotment for several years. For those of you who don't know what this is, it's a creeping, thistle like plant that seems to love cultivated land. It comes up in late spring and seems innocuous enough at first, but soon it's everywhere, taking light, water and nutrients from your crop. Then come winter, the ground is thick with its brittle, spaghetti like roots. It's easy enough to pull up, but you can never get rid of it.
So, about this time two years ago, before the sow thistle showed its head in spring, I sowed the ground with mustard. This was to feed the soil. About the time the mustard started to flower, up came the sow thistle. I then covered the lot with 1000 gauge black plastic. The plastic stayed on until late autumn and all the surrounding ground was cultivated. Any sow thistle peeping out from under the plastic was pulled out. Then I took plastic up to let the winter rain in.
Unfortunately around Feb last year my husband got Legionnaire's disease and I was unable to get on the plot for six weeks solid. Given that I could only ever spare one afternoon a week for it I felt I wouldn't be able to keep on top of it that year so gave it up. I did, however, go back to see if the sow thistle had reappeared at all and took some photos. There was no sign of it whatsoever, and no live roots in the soil that I could see.
Hopefully, I can post the photos below.
While I understand this probably wouldn't be a viable method for a commercial grower as it entails leaving ground uncultivated for a growing season, it does show that it is possible to eradicate some of the weeds that plague us. I would like to stress, however, that thick plastic is needed for this, and that the weed cannot be allowed to sustain itself from roots attached to plants growing outside of the plastic.
Phew - finally wrote this post!
So, about this time two years ago, before the sow thistle showed its head in spring, I sowed the ground with mustard. This was to feed the soil. About the time the mustard started to flower, up came the sow thistle. I then covered the lot with 1000 gauge black plastic. The plastic stayed on until late autumn and all the surrounding ground was cultivated. Any sow thistle peeping out from under the plastic was pulled out. Then I took plastic up to let the winter rain in.
Unfortunately around Feb last year my husband got Legionnaire's disease and I was unable to get on the plot for six weeks solid. Given that I could only ever spare one afternoon a week for it I felt I wouldn't be able to keep on top of it that year so gave it up. I did, however, go back to see if the sow thistle had reappeared at all and took some photos. There was no sign of it whatsoever, and no live roots in the soil that I could see.
Hopefully, I can post the photos below.
While I understand this probably wouldn't be a viable method for a commercial grower as it entails leaving ground uncultivated for a growing season, it does show that it is possible to eradicate some of the weeds that plague us. I would like to stress, however, that thick plastic is needed for this, and that the weed cannot be allowed to sustain itself from roots attached to plants growing outside of the plastic.
Phew - finally wrote this post!
