White flowers on the purple-leaved Physocarpus opulifolius in May. APugach/Shutterstock

I like physocarpus, which goes by the common name of ninebark, for a lot of unrelated reasons.

First, it is gorgeous in all its many different forms. The bush can be wine red, green and golden. It can be just 3-feet tall, the dwarf variety, or can have 15-foot-long arching branches with tips that almost touch the ground.

Also, the bushes are promiscuous – growing from seed that falls each autumn – and the offspring may be a different color from its parent. We have had a red physocarpus that produced a golden seedling in our garden by the driveway, while a friend’s red bush produced two green seedlings. About 20 years ago, the crew at O’Donal’s nursery in Gorham found a seedling shrub that started out chartreuse, then turned to golden as it aged. The nursery planted cuttings, which they now sell as “Gorham’s Golden.”

New plants are also created from where the roots spread underground. A little human help is good: Put a freshly cut stem in a pot and keep it moist and cool from late fall until spring. You’ll need a stem about a half an inch wide and 6 inches long with at least two leaf nodes. And by cool, I suggest an unheated cellar or bulkhead. When you plant your seedling, be sure to keep it moist, as it won’t be fully rooted for a year.

The plant’s history is a bit strange – and I like strange. As a green plant, it’s native to Eastern North America from Canada all the way down to northern Florida. It grows mostly on stream edges. But it never entered the commercial trade until a group of ninebarks were shipped to Germany in 1968 for use there.

Among all the green plants there happened to be one with foliage that was dark red, almost black. The grower recognized that color would have serious value in the commercial market. He propagated it from cuttings – which is how cultivars are produced to ensure they are all the same. The grower named it Diabolo, and it is still on the market 20-plus years later.

Although the foliage is the main attraction of physocarpus, the flowers also are pretty. The flowers are usually white, but red physocarpus produce flowers with a reddish tinge.

What about winter interest? The name “ninebark” comes from the peeling, nice-looking reddish-gray bark which was thought to have nine layers – but, no, there are not exactly nine peels on each piece.

Physocarpus does not need a lot of care, but we prune ours every four or five years just to keep it from getting massive. During late fall, or in the winter, we’ll cut about a quarter of the stems as close to ground level as possible, to give the shrub more air flow. The one complaint some people have about ninebark is that it is susceptible to powdery mildew; I’ve never seen that, but if it became a problem, better air flow would help.

If you want to start fresh, you can cut the entire plant to ground level, and it will re-sprout from its roots. Or so I’ve heard; I haven’t actually tried that.

One of the volunteer physocarpus at our friend’s house would block the ocean view from her kitchen window if it got taller than 4 feet, so that one gets pruned each year after the blossoms go by. Such pruning should be completed by mid-August to ensure that the bush will blossom the next year; if you prune any flowering shrubs late in this year’s growing season, remember that you’re cutting off next year’s flower buds. We give our friend a hand, taking the tallest branches down to ground level and cutting back the others to about 4 feet where a leaf comes out.

Just as parents should not favor one plant over another, gardeners should not favor one plant over another. But as a native that never became popular until it took a European vacation, physocarpus is close to my heart.

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