Aaron> "Lisa" writes: >> Hey all -- was gone for the weekend and went to take a look at the >> garden yesterday (which up until this weekend was doing A-OK). >> Well, my beautiful tomato plants were all branches and limbs. No >> leaves. No tomatoes. Got to looking closely to see what the heck >> happened to my plants and there were horrible green horned >> caterpillars. Looked them up and discovered they were hornworms. >> Some of the biggest, fattest, ugliest caterpillars I have ever seen. >> Peeled off and destroyed as many as we could find and then sprayed >> herbicidal soap on what was left. Are my plants ruined? Am I done >> for the season? Or will they come back and produce?
Aaron> It's hard to say. The branches that were eaten back probably won't Aaron> grow again, but tomato plants usually have a lot more foliage than Aaron> they need, especially if you don't prune them like some people do. Aaron> I've seen some very shorn tomato plants produce quite a few tomatoes.
Aaron> The best defense against tomato worms is to check your plants every Aaron> day. The worms themselves can be hard to spot, but the damage usually Aaron> stands out quickly. Also, if you happen to see a worm with a bunch of Aaron> white things sticking out from his body, those are the eggs of some Aaron> sort of wasp. Don't kill that worm; the eggs will hatch soon and the Aaron> wasp larvae will eat the worm, which is the sort of thing you want to Aaron> encourage.
I have found Bt very effective against all forms of caterpillars. The hornworms are very hard to find in
18 large plants, and usually I only find them by looking for extensive damage.
I encountered my first hornworms when growing tomatoes in pots on a 17th floor balcony in NYC.