I think they will likely come right up through it, but you might want to brush some of it aside if you can easily over where they are planted. THe main thing for me seems to be making sure they do not dry out. IN a few years they will act as the mulch and no weed will find room to grow between them!

Exactly! I am going to dig a bunch of the lillies of the Valley up...hope to give them away. Way too many.

oh phooey, mine never came up. i think they just rotted and became very expensive fertilizer for the other plants there. oh well. i won't be doing those again :(