Are you saying that grass is growing up against the plants(not a great idea), or @ the base of the mounds? Can you post a picture?

Also - wrong time of year for broccoli, I'm afraid it may be doomed to fail.

Here is a link that might be useful: FL Veg Gardening Guide

Hi Carol_w_fl:

I do go by the FL Veg Gardening guide and I did get my broccoli in late....thanks anyhow....

And yes...my mounds are on the west side of my home (longest sunlight exposure) and they are right in the middle of my lawn. There's about a 6 inch ring of yellow-ish grass around the base of each mound...and it just happened over the weekend.....I'll post a picture in the morning so all can see.

What are you using to fertilize your organic plants? Something is more than likely coming from the plants and the grass does not like it. Did you dg the grass up underneath the mounds or did you place the mounds on top of the grass? Depending on the type of grass you have that could be part of the problem.