Mary

BT doesn't prevent hornworms from coming to your tomato plants but only kills them once they're there. Do you plan to be away again while your tomatoes are growing? If you're going to be around, most people who want to be as organic as possible just watch their tomato plants carefully and handpick them off when they catch them on the plant. Otherwise you can spray them with BT. They die from eating the sprayed leaves, though not immediately. It takes a few days. It's up to you and your circumstances what's the best thing to do.

Good luck!

Here is a link that might be useful: How to Handle Hornworms

Agree with anney that daily plant monitoring is the best solution.

It isn't so much an "infestation" of hornworms as you seldom find more than 1 or rarely 2 on each plant. But that one worm if not caught and removed earlier can do enough damage to make it look like there must be 20 of them on each.

If you allow the ones with the wasp cocoons on them to survive so the wasps can hatch then you have a great control in place for the following season. If you kill them then you lose the benefits for later and the infested worm can't do any real damage once he is infected.

Otherwise, yes, if you simply can't be there to monitor and hand pick then row covers may be the best option.

Dave

I've never seen a hornworm, and Hope I dont! But best of luck to you... I even see insects just appear in my house chilling on my indoor grow of tomatoes. This morning a lady bug for example I found trapped in the tomatos trunk hairs. Like the old saying, slightly modified. If you grow it they will come.

I wonder if a bug zapper in the area, but far enough away to draw the moths away from the tomatoes would work. My brother had a zapper at the edge of his yard between the wilderness and the garden and all kinds of moths were killed. It would probably be a good thing to have over top of the compost pile.

Good thought SH, the moths responsible for the hornworms are quite large---would be an intersting ZAPPPPPP if they could fit into the zapper.

Also, not all moths are bad. Moths can also be pollinators.

Hornworm moths (sphinx moths) are known pollinators (although I doubt they would bother tomato blossoms other than to lay eggs).

I hand-pick my hornworms and if I feel like it, I rear them indoors rather than killing them. One day though, when I have a much larger garden, I'm sure hornworms will be too much of a problem to just bring them in and rear them all. That's when the killing will start for me...

Also, I've heard that planting basil as a companion will deter insect pests. I've got some sweet basil planted between my maters this year, and I'll see if I get any hornworms or not.

A hornworm ate my basil. In one night it ate half its leaves. I searched each leaf but could not find it until the 5th day. I started picking off damaged leaves and baby hornworm fell on soil where I saw it easily. It was onky 1/4 inch long but did so much damage.

I read companion plantings like basil, borage and marigolds work for some. I'm trying it this year.

Hey Guys; There is a better way. I pinch the first true leafstem hard enough to break the epidermis but not hard enough to completely remove the leaf. This causes the plant to produce an over abundance of "proteinase inhibitors", which is letthal to the immature hornworm (the same ones that are used in the treatment for AIDS). You need to do this when the plants are 4-6 inches tall. It works like a dream for me and I have been using this technique for years. If you are tired of hornworm's what have you got to lose?

>>>If you're going to be around, most people who want to be as organic as possible just watch their tomato plants carefully and handpick them off when they catch them on the plant. Otherwise you can spray them with BT.?

BT is as "organic as possible".