Tammy,

Possibly cutworms. They have been a problem for me in the past. Cutworms seem to like zinnia seedlings. I always dig down with my finger around the remaining stem to find the culprit and destroy it. Sometimes it takes several minutes to find it. Some people use a little protective collar on their seedlings, but that isn't always effective, and it is a rather tedious thing to do. So far I haven't used poison sprays to control cutworms, but a spray containing Bacillus thuringiensis kurstaki might be effective to kill the cutworms while they are still in their juvenile "free ranging" stage. The Bt sprays are non-toxic.

ZM

ZM, I looked those up online, and I have seen those in my soil before. So those could very well be the problem. I will see if I can locate that spray. I hate to use any poisons, but I have to do something to stop them.Thanks a lot for the info.
Tammy

Cut worms do not eat the plant. Cutworms cut the stem off at ground level and feed on the roots. They don't come in groups--there is only one directly below the cut off stem. I don't usually have much of a problem with them so when I see a cut off plant I dig down, lift the sucker in my trowel, drop it on the ground and step on it.

If you have a lot BT dug into the soil around the plant will work.

If just the leaves are eaten then I'd tend to think it's your old friend slugs or maybe earwigs. The only way to tell is to take a flashlight out after dark and see what it is

I have not found any plants cut off. Whatever it is, only eats the zinnia's. and starts at the leaves.
Tammy

Tammy,

If you haven't found any plants felled, then it probably isn't cutworms. Oilpainter's suggestion to use a flashlight after dark to catch and identify the culprits in action seems like the best plan. There is plenty of information on cutworms in the garden on the Internet.

ZM