Is there anything that will keep hornworms away?
 

My tomato plants get hit with these huge caterpillars every year. Is there anything I can plant to deter their interest in my tomato plants?

Yes. BT. Spray your tomato plants with it and they will die after one bite.

Thanks. I only have a couple of plants so I'm going to try something someone told me about since making this post. Basil planted around the plants is supposed to be a natural deterrent. The only thing I use on my plants has been Neem Oil spray which has worked great for everything except the tomatoes.

BT will work a lot better than basil. If you're not familiar with it already, be sure to look it up.

Soil drench.
 

They hang out in the soil at bottom of plant(sometimes the worms come in your mix if store bought,pro mix for me).When first hatched they come out at night crawl up eat,crap,go back down.When larger they will hide under a leaf blend right in camouflaged( the green ones).There is a brown hornworm also.I follow the crap trail to see. A good soil drench with some BT Will nock them down in ground,otherwise BT on leaves will kill them as mentioned above.I do admire the moth that evolves markings and colors are vivid.

I use the "High Shower Button" on my Garden Holes.

I need to get ready to place my Big Transplants Tomato Plants in the Ground because my Chesapeake Heirloom Tomato Plants are Blooming. These are very strange weather conditions for us Farmer, Amen!!