Jan, Those pyrethrum bombs are kind of scary. They use a flammable dispersant so you could blow your greenhouse up if you weren't careful. Pyrethrums are quite dangerous to people despite their natural origin. Plus, they don't make one small enough for my 9x11 greenhouse. One year when I was desperate, I used one anyway, and my goodness, it really worked. But I didn't go into the greenhouse for over 3 weeks, and then I held my breath! It really cleared out the spider mites (my personal nemesis).
I actually might use one every couple of years if my greenhouse were bigger. I think that the Pyrethrums spared nothing- even killing slugs and slug eggs! Plants acted very frisky after the treatment. I didn't have any ferns I was trying to grow in the greenhouse at the time, but there were a fair number of those little maidenhair ferns that are a weed for me, and I don't think I noticed that they took any harm from it. Ilse Burch Sammamish, WA, USA zone 7+ Currently a balmy 40 F with wind blowing _______________________________________________ Alpine-l mailing list [email protected] http://mailman.science.uu.nl/mailman/listinfo/alpine-l
