Peonies grow along the fence line in columnist Tom Atwell’s garden. Now is a good time to divide and move them. Photo by Tom Atwell

My wife Nancy and I have to transplant some of our peonies. Yes, I know peonies are tough plants that last forever, producing gorgeous blossoms mostly in May and June. You really shouldn’t have to move them, ever.

It’s just that they are getting crowded in a prime spot next to our driveway and the door of the house that we, and guests, use most frequently. In typical Maine fashion, we call it the back door.

Four years ago, regular readers may recall, we removed a birds nest spruce from our garden that garden catalogs had assured us had an ultimate height of 3 feet. While attractive, ours had grown to more than double that and blocked the views from the family room, which is the space where we spend most of our waking hours.

We ordered a few peonies from Fedco, and we planted them where the spruce had stood. But the area still looked naked, so we divided some peonies that grew elsewhere on our property and added those, too. Four years later – to no one’s surprise – the peonies are getting crowded.

Fall is the best time to dig, divide and move peonies, as long as the work is completed five or six weeks before the ground freezes solid. That interval gives the roots time to settle in and grow before going dormant for winter.

The peony patch by our back door is about 10 feet square, and it contains about 25 peony plants. We won’t dig all of them this year because divided peonies, both the parts you move and the parts you leave, have few if any blossoms the following year. To get blossoms next summer, we’ll do our division job over two years.

Each divided plant needs a few “eyes” to ensure the new peony will thrive. Photo by Tom Atwell

Dividing peonies is not difficult. Before you begin to dig, cut back the foliage leaving 2 to 3 inches. Dig around the plant, taking care to cut as few roots as possible, then lift the entire plant out of the ground. Our spot is crowded, so we’ll move the plant to a nearby tarpaulin, where we’ll use a sharp knife to cut and pry apart the roots into several pieces. Be sure to leave three to five “eyes” or growth nodes on each root piece to ensure the new plant will be large and healthy.

When you replant the peony, whether in the existing hole or the new location, place it so that the nodes are no more than 2 inches below the surface of the soil. Too deep, and the peony will produce excellent foliage but will not blossom well. Before planting, scatter compost or a good organic fertilizer at the bottom of the hole. After planting, water heavily.

Peonies are not the only plants that can be divided in the fall. As a general rule, spring-blooming plants should be divided in the fall and fall-blooming plants in the spring. Nature is considerate in spreading out the workload that way. But the real reason is that producing flowers takes energy from the plant, and when you divide a plant you want all the plant’s energy going to the roots.

Nancy and I also have some hostas that have also outgrown their space and will have to be dug, divided and moved. Some of them may disappear altogether because we have no idea how we got so many plain green hostas when the many variegated versions are more interesting. Follow the procedure for dividing peonies, but no need to cut the hosta leaves unless they get damaged in the process.

When I wrote about daylilies a few weeks ago, I said it’s best to divide them right after they bloom. If you haven’t yet got that done, you still have time.

Siberian irises can also be divided and transplanted now, although the collection of McEwen irises were transplanted to Coastal Maine Botanical Gardens in early spring. In the spring, dividing should be done before the leaves are 4 inches tall. But you could also divide them in the next couple of weeks if you trim the leaves to 6 inches tall and cut the rhizomes with a sharp knife.

But I’ll have enough to do with our peonies and hostas.

Tom Atwell is a freelance writer gardening in Cape Elizabeth. He can be contacted at: tomatwell@me.com.