What can I do to prevent giant caterpillars from attacking my tomatoes

Below is an article from HGTV that should help you. Wishing you the best & Happy New Year!

http://www.hgtv.com/outdoors/gardens/planting-and-maintenance/worm-hole-help-caterpillars-are-eating-my-plants

I use a spray of cayanne pepper powder and garlic powder missed in water with a few drops of blue Dawn dish soap so it sticks to the plants. You just need to rinse the nozzle occasionally, sometimes it gets clogged

https://www.almanac.com/pest/tomato-hornworms

Maybe put some fine crinoline netting over them. I would make some bags of it to fit over your plants, Poke a couple bamboo sticks around the pot/area and then drape the bag over it, and put a few stones at the bottom to hold in place. Crinoline can be brought at any fabric store or online, its really wide and cheap, use a long stitch on sewing machine to sew up a bag

A. Best method is to inspect frequently and literally pick them off (and destroy. ) I know, it's gross. Use gloves.

B. Check at your garden center for a powder you can dust on the plants. Must be reapplied after rain, though, and has instructions that MUST be followed EXACTLY to prevent contaminating the tomatoes when you pick them to eat. This is a poison.

Ah the infamous green tomato horn worm! Easy to go out in the morning and pick them off the leaves. Usually near the stem. Put them in a bucket and feed them to the chickens for a treat.