Ask the Gardening Expert

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We want to do some major overhaul in our front yard. We'll be moving some shrubs; we've had shrubs and trees in the landscape, but no flowers until this summer. We now want to add more perennials. I have a few grasses, and want to situate them differently. Should I do it now or is it better to wait until next spring? I planted it last year and it is about 3 feet tall and 2 feet wide. There is a Rose of Sharon and a lilac bush that are too close together. I'd like to move the Rose of Sharon. It's about 10 years old; about 5 feet high and 3 feet wide. It has one main trunk, so it looks more like a tree than a bush. When is the best time to move it? Finally, I planted my first perennial flower garden this year and the plants are spreading rapidly. Can all perennials be split?

Both spring and fall are good seasons to transplant, dig and divide and do all kinds of things with your landscape. This is because temperatures are generally mild and rainfall abundant, both of which will lessen transplant stress. If you're not inclined to get out in the cold autumn weather, you can wait until spring to do your moving and dividing. (As I write this the afternoon temps are in the 70s here in October.) Your grasses won't mind being moved in the spring. Simply dig them out, taking as much of the root system as possible, and replanting. Make sure they are planted at the same soil level as they were growing before (not too deep, not too shallow). Water in well after replanting. Your Rose of Sharon will appreciate being moved before it begins to grow in the spring. Think of it as going into surgery; wouldn't you rather they do the operation while you were asleep? Wait for it to go dormant. A shrub that's been in the ground for 10 years will have an extensive root system and if you move it while it is actively growing, you may set it back considerately. If it's moved while it is dormant, it will barely notice the change. As for your perennials, in most instances you can divide them by simply placing your shovel or spade in the center of the plant and cutting right through the foliage and roots. I use a garden fork to lift the perennial out of the ground and then cut them into several divisions. As long as each division has roots with some stems attached, each should recover and grow well. Most lift out easily, but there's a few that are tougher than nails, such as old stands of ornamental grass.

Early last spring I purchased some Pink Skullcap from a local nursery and put it in my window boxes. I love the plant with its delicate pink flowers but know nothing about it. I'd like to know about the plant and how to care for it.

Pink Skullcap is Scutellaria. It likes full sun to part shade, and well-drained soil. It's a member of the mint family, square stems and all. Skullcap is a perennial herb that will grow 12 to 15 inches high. In Ireland it was used to treat insomnia. It's native in some of the Southern states. Your Pink Skullcap will bloom from May through June, and perhaps longer if gets water, and good drainage. Keeping it deadheaded encourages the plant to continue setting buds.

I'm looking for perennials (plants and shrubs) that will bloom in either summer or fall. All of the perennials in my garden are done blooming by the end of July. I would like to get some summer and fall color into the garden. I have full sun and sun/partial shade areas and lots of space.

Here are a few perennials that bloom later in summer, and into early fall. How about trying Japanese anemone, black-eyed Susan, Joe Pye weed, phlox "David," Boltonia (pink and white), asters, sedums such as "Autumn Joy."

You might also add some flowering shrubs such as caryopteris, crape myrtle (nowadays there are newer, hardier types available) and butterfly bushes since you have lots of space. Ask the nursery worker for the newer sterile spices of buddleja.

You might email the WSU Master Gardener office for lists. The master gardener on duty will be happy to forward lists that give you ideas for your garden. You may reach the master gardeners online MGanswerclinic@clark.wa.gov or by phone, 397-6060 ext. 5711.


Celeste Lindsay is a WSU-certified master gardener. Send questions to mslindsay8@gmail.com.