Monday, June 22, 2009

Pest Control (Chemical-free)

The ominous-looking white powder on the plants above is diatomaceous earth. I've been using it for the last three or four years to keep pests at bay. Last year was the most serious I've been about it. My potato plants were full of flea beetles and Colorado potato beetles, so I regularly sprinkled this stuff on top and underneath the leaves. It doesn't work once it gets wet, so the most effective way to apply it is after a rain or watering, when there's a chance there will be at least a full day of dry weather. You have to reapply after each rain. Diatoms are a form of phytoplankton found in both salt and fresh water. They are a microscopic algae that have very sharp shells made of silica. They are really beautiful under a microscope. Diatomaceous earth sucks the waxy layer off of an insect's exoskeleton, and then it dehydrates. Slugs and larvae also desiccate when they come in contact with it. So, it's nice to have something to keep the insects from chewing devastating chunks out of your plants. But I do use it sparingly considering the not-so-fun consequences for the insects. Also, I've decided to use it sparingly during pollination times. It's a great tool for the early stages of plant growth when the flea beetles and slugs can do real damage to tiny plants. Once the plants get big and healthy enough, they can survive some insect snacks.
This year I've put the diatoms on potato plants to keep the flea beetles from doing too much damage. I also put it on the small tomato plants when I found a couple of flea beetles there, but they didn't ever do too much damage anyway. All of the cucurbits were getting munched when they were tiny, so I used it on them. My zinnia and sunflower plants were taking a beating, too, and after a couple of days of the stuff, they were able to get ahead of whatever was eating them and now they look very robust. Just for the heck of it, I sprinkled it on the tiny carrot plants to attempt to keep root maggots from making homes in my spring carrots, but then I had second thoughts of continuing the experiment because I always find black swallowtail caterpillars on the spring carrots.
I've just run out of diatomaceous earth. A four pound bag lasted me one and half seasons. I've got to track some more down today. I bought my last bag at the Agway in Pulaski, NY. You can also get it at pool supply stores because it's used in some pool filtration systems. It's also sold as a household treatment for ants and roaches. I always used gloves when applying it, but recently I used my bare hands. I try not to breathe it or get it in my eyes. I wash my hands immediately after I'm done because you can get a scratchy, dry feeling from it. But I haven't had any lasting reaction to it at all.
Floating row covers can also keep pests away, especially if you secure them with soil or other more substantial anchors. The ones above are mostly to get the soil and ambient air temperature up around the peppers and tomatoes on cool, cloudy days.
There's a little flea beetle and the tiny holes they put in potato (and plenty of other) plants.

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