Ask the Garden expert

Do you ever cut back peonies? If so, when is the best time? After blooming, during the summer or late in the fall?

Peonies need those stems and leaves to function through the growing season in order to stay alive and healthy enough to bloom. In late fall after frost has killed back the tops, gently remove the stems and clean away any fallen peony leaves. This will help prevent any carry-over of pest or disease from year to year. Don’t forget to mulch over the soil surface to protect the roots. Allowing the foliage to remain until death will help the roots collect as much nourishment as possible (through photosynthesis) and will ease the plant into dormancy.



I noticed that a variegated dogwood in the neighborhood now has mostly green leaves. Do they change over time? I wanted to plant one in my yard, but already have a green one so what other variegated tree would stay its own color?

Most variegated trees are grafted. Yes, I have seen lovely grafted variations revert back to green. It’s too bad, since the color is probably why most folks bought that tree in the first place. What happens is that the root stock is the normal green, and the variegation is grafted on when the tree is very small. The green always wants to dominate, since that’s what the roots are. If left on the tree, the green will try to take over and will certainly achieve that goal in time. The thing you might keep an eye out for when you get your tree is branches of green; remove them before they take over.



I was looking for a class on greenhouse operation, and I know about the ones at Clark College. I realize they are full of great information, but I work full time and would be unable to take off work to attend a quarter at this time, I was hoping I could learn a little about just where I might begin?

Well, your timing is great. Charles Brun, the Horticultural specialist at Washington State University Clark County Extension in Brush Prairie, is sponsoring a class on this very subject in October. The class, called Greenhouse Nursery Workshop, will be held Oct. 18 from 9 a.m. to 3:30 p.m. The class will include a tour of three commercial nurseries in the Ridgefield and Battle Ground areas. The registration fee of $25 includes refreshments, lunch and handouts. For information, call 360-397-6060 ext. 7713 or e-mail brunc@wsu.edu.

Celeste Lindsay is a WSU master gardener. Send questions to lindsay8@pacifier.com.