Can u get a pictur of the larvae?? I'm not to sure a cut worm would kill a larger plant usually only seedlings are killed what kind of cut worm ?? Need more info as far as control if it is the cut worm I can't think of Any non chem controls even with chem you could try sevin 5 bait around the base not touching the plant but the worm would have to go for the bait and not the plant example cut worm in corn I've seen it where the worms are not attracted to the bait and literally will avoid the bait and make there way to a plant that they can get to without having to eat bait little buggers I find them all the time in my garden and yet to see a plant die from them the larvae you say do they look like maggots ??

They kind of look like grains of rice and they can wiggle. They are right where the stem meets the ground.

I buried them and it's dark now...I will try to get a photo tomorrow.

I would suspect that you have cabbage root maggots which attack most of the brassica family.

Here is a link that might be useful: Cabbage root maggot

Yes, cabbage root maggots, and I'm afriad there is nothing to be done. The fly what laid the eggs is long gone. Some people say that pressing the soil down firmly around transplants deters egg laying, but I don't know. I've only had trouble with them in August, with plants being grown for fall harvest, and then it's a scattered plant here and there.

I wonder if a soil drench of a neem solution or similar would help? I've never had that particular pest (yet, I won't rule it out from worming its way into my garden) so I don't know how to combat it. Good luck!

Thanks For Everybody's Help

I Googled "cabbage root maggot" and I got this Wikipedia page:

http://en.wikipedia.org/wiki/Delia_radicum

This is exactly what is affecting the plants.

I buried the stems roots with more soil.

The only way i've been able to avoid them is to keep susceptible brassicas under floating row cover. I have to do this for all my napa cabbage in the fall or they all go downhill just like your broccoli. Good luck