Perhaps a hornworm? They leave pellets behind. My other guess would be nematodes but I know nothing about them.

If it is the hornworm, check for a big green catapillar. Those things blend right in with the stems and leaves.

Yes, I have seen the big green worms before eating leaves off stems and leaving small black pellets. But these plants are chewed off right at ground level. I think they must be fairly large, the stalks are chewed right through.

Thanks for your input.

It sounds like cutworms. Is the top of the plant just laying there beside the stem? If so, them I'd bet on cutworms. Some will climb but most just encircle the stem right at ground level and cut it off. There are several different controls available ranging from cornmeal to collars to a nail stuck in the soil to prevent them from circling the stem. Just do a search here on cutworms for lots of info.

If the top is gone or clearly chewed on, then it can be birds, deer, rabbits, even field mice.

The other possibility is damping off - a fungus disease in the soil. It usually only affects seedlings but can occur in established plants as well. Good luck.

Yikes,it got another plant yesterday. I got some Corey's Snail, Slug and Insect bait and sacttered in the beds the day before. Advertized it was effective against cut worms.
It is like the regular snail bait, but has some added ingredient that is supposed to be effective against insects. But... it didn't seem to phase this critter This time, it looks as if an inch or so of the stem has been eaten.

I am beginning to suspect somthing other than worms, maybe rodents. Set my trap tonight.

This thing has gotten 5 of my 12 plants. Starting to get a little worried.

Critters got two plants two days ago. I got some garlic based repellant and scattered it around the beds. Supposed to be effective against rodents, rabbits, deer ... etc.
Nothing this morning. That's one in a row.

All has been well for a few days now, but last night the critter got another plant. The stalk was chewed off right at ground level and the plant seemed to be pushed, or maybe pulled, down into the soil. Probing around the plant, I am unable to find any burrows. This guy is ignorig the the fruit. There were three developing green fruit just above the cut. There were no marks on any of them.

I don't understand how the stem would be pulled into the dirt without some kind of burrow. I think I have seen that with some of the other plants I have lost. I'll have to try digging around carefully in the area to see if I can find anything.

Sure could use some help.

I have no idea if this will be of any help. I have been battling a gopher. He/she cuts off my balloon flowers (every year!) down to ground level and then pulls the plant down the hole. I have actually played tug with this destructive fellow, catching him in the act, I was not going to let him have his "prize". He was yanking the plant down, and I yanked back (I'm bigger so I won). However, I do not know if they like tomato plants? What I did was to make a paste of hot pepper, garlic and oil and spread it around the stem. He has not cut off any since I did that.

kendra2
I have just about conclued gophers are my problem. I realized that the plants were not just cut off, but the end was pulled down into the soil. Never had any real time with the critters and I could never find any kind of hole the stem was being pulled into and the roots were still completely intact. But I did find some rather large tunnels, much larger than mole tunnels, in my tomato bed and outside. I got some poison blocks, sort of parafin with seeds imbedded and some nast stuff, blue, and put some in the tunnels I could find outside the garden. Closed up the hole without filling up tunnel. I was gone on vacation for a week and havn't lost any more like that so maybe that was it. My Roma has lost all of its leaves, but I think that is something else. Early Girls are starting to produce.

Thanks for you response, kendra2. Wish I could have been there while you and the critter were having a tug of war with your flower. Sounds like somthing out ot Lunny Tunes.

So tomb123, did you ever find out for sure what was getting your tomatoes? I just had the same thing happen.

Our 2 foot tall tomato had 6 stalks, 1/8 to 1/4 inch thick.. All were mysteriously and cleanly severed. 4 other plants left untouched... They are in pots on a cement porch, so not gophers.