Saturday, June 20, 2009


Spirea ‘Anthony Waterer’ (Spiraea japonica)

While we’re talking about reliable plants, Spirea shrubs are a candidate for this class.

The old shrub ‘Anthony Waterer’ came with our house. Over the years, a locust tree grew to provide dappled shade.

‘Anthony Waterer’ grows as a rounded mound about 3 feet high and wide. The leaves are dark green with white or variegated sports thrown in here and there. (The golden or yellow cultivars like ‘Lemon Princess’ are brilliant against darker shrubs or evergreens.)


That said, the plant comes with a warning -

According to the Pennsylvania Department of Conservation and Natural Resources list of invasive plants in Pennsylvania, Japanese Spiraea is “Frequently planted; escaped in some areas.”

”ECOLOGICAL THREAT: Japanese spiraea can rapidly take over disturbed areas.

“BIOLOGY & SPREAD: A single Japanese spiraea plant produces hundreds of small seeds that are naturally dispersed by water and deposited along stream banks. Seeds may also be carried in fill dirt and establish new populations in the highly disturbed soil of construction sites.

“Spirea has cultivars that are not known to be invasive. . . . If you choose to plant a cultivar of an invasive species, ask a PA certified horticulturist (PCH), your Penn State extension agent, or a professional horticulturist about the cultivar's potential to be invasive.”

I make sure to dead head the shrub to remove the seeds. It was trimmed back to about 8 inches in the middle of March. When blooms begin to fade, I’ll use a hedge clipper to cut it back. It will bloom again and the blooms will continue into fall. Then I’ll give it another haircut. I haven’t heard any reports of Japanese spirea becoming invasive in our area.

Perhaps it’s the reliability of this plant that is also it’s curse.

(More information on spirea from Clemson University Extension.)


donna said...

I had no idea that the Japanese spirea could be so naughty. Plenty of spirea in our yard but I don't know the names of them. None are bit invasive, so I won't worry.

Marie said...

I haven't seen any signs of invasiveness here either.

Morning Glories in Round Rock said...

It is amazing how many plants being sold are invasives. I think you are very wise to keep yours trimmed to insure it doesn't spread. They are beautiful shrubs. I have not been able to grow them because the deer think they are a delicacy.

Marie said...

Spirea seems easy to control unlike the burning bush we had in our front yard. We cut it down three years ago but I still find seedlings to pull out.