Linda, I have found Evening Primrose hard to get started before too, which is odd considering how it behaves once it settles. Those little thread like roots don't seem to hold a ball of soil and then resent disturbance. I have resorted to potting up pieces I've dug, then I sat the pots in the shade and kept them moist for a week or two. Those transferred into the garden without issue.
I've stopped using chemicals in the garden, so no Preen here. I also have some self seeding annuals that I want to keep around.
