Best to put some sort of root barrier between them and anything you have
that's desirable. They can send runners quite a distance under the soil -
not just adjacent places. However, the one that's far downhill probably did
wash down. Just a tuber fragment is all it takes to get a new plant.
"Bobby Baxter" wrote in message
. com...
Sounds like you have one of the species types of daylilies. They spread
by
sending runners under the soil. They will spread fast and give you a
great
show when they go into bloom. If they start getting where you don't want
them, then get out the roundup and fight tough.

Bobby
http://happymoosegardens.com