We currently have plain old grass on top of the drain field. My husband heard somewhere that code requires grass, and that is the only thing you can grow above it. So far, we haven't been able to find anyone who "knows" about these things. I understand not wanting roots to corrupt the function of the drain lines, but I'd much rather plant something else. Firstly, we're trying to eliminate mowed grass from our property- -I know, we're nuts. Secondly, I'd like to plant something aromatic like lavender. So, who out there knows the nature of septic fields? What are my limitations for planting? No hurry, we've got oodles of time. The grass can stay, especially if it has to. But, it's fall, and as soon as I finish the giant hole in the front of my house, I'll be dreaming of how to landscape our new facade. Thanks for any ideas!