Poison oak is also excellent at holding hillsides.. and I hate bindweed (Convolvulus).. but not nearly as bad as Euphorbia cyparissias which I got from Western Hills Nursery many years ago. The sweet flowers and soft, needled foliaged lured me... Now it's growing in everything.. Last winter I made a concentrated effort when it was dormant to dig it up, but like Bishop's Weed, every little piece of root that's left will grow. I made good progress, but unless I keep after it.......
You can see it growing at the base of 'Hello Darkness' and through all the other iris... (before I took the spading fork to it)
Euphorbia robbiae is the other one I wish I'd never planted... I was hoping it would be a gopher barrier, but I got was sap in my eye and a visit to Urgent care, with probably the worst pain I've had since childbirth. Beware the Euphorbias!
