I have the same problem with the lily bed in my front yard. I'm thinking of seriously just , with a shovel,
taking each clump out of the bed and placing (perhaps on a large tarp) in the shade. Then, the bed can
be tilled up deeply, more easily clear of grass, fertilized, amended. Then move the lilies back into the
nice rich clean bed where it can be much more easily maintained. I have about eleven different ones
and would be sad to lose any of them.
Louise