oenothera speciosa in heavy clay
I have about 20 small starts planted into a VERY difficult place and I'm wondering if they will be able to spread. I know many people are cringing reading the name and invisioning their fight with this invasive plant, but here's my dilemma.
We have a rather steep slope which leads to a small (4-5') sheer cliff on what was once a boat ramp (I can imagine maybe getting a canoe down it but not launching a "real" boat). It is right on the lake. It was just redug to repair it due to erosion so now it is bare soil. It has a LOT of clay. As in, grab a potting wheel and make yourself some clay pots-there's very little top soil. I need a good spreader with dense root systems that will hold back this soil/clay. I have planted in some yarrow (mostly along the top where there is some top soil), ditch lilies, lily of the valley and primrose. We overseeded with crown vetch and alternative lawn but it's steep enough that we're afraid the seed will wash down. We are also going to start some crown vetch so we can plant little plants instead of relying just on seed.
Has anyone had success with primrose (this is the "showy" or Mexican variety) spreading in heavy clay?
There is not a tended bed withn 200' of this location, just mowed grass, so it will have a hard time spreading by sucker into a bed.