CHARLESTON, W.Va. -- Always on the watch for new plants that don't cause problems down the road, this fragrant, long-blooming butterfly bush definitely caught my eye.

While buddleia is great for attracting butterflies and hummingbirds into the garden, they reseed and send little butterfly bushes throughout the garden. They are often found on lists of invasive species for this reason.

The Asian Moon butterfly bush is a classic summer-flowering shrub that begins flowering in June and continues into late fall, according to its originator, Dr. Jon Linstrom of the University of Arkansas. But most important to me, it doesn't set seeds (it's sterile), so it flowers more often and doesn't spread like many of its counterparts.

Linstrom is a member of the Garden Debut consortium of breeders, growers, retailers and marketers. His Asian Moon buddleia is a large, symmetrical shrub that can reach 7 feet tall, but is easily cut back to maintain size and promote reblooming on new wood. Because its sterile flowers don't set seed, it is a great alternative for gardeners who don't want to have buddleias throughout their landscape. The sterile flowers have a prolonged bloom period compared to fertile varieties, a gardening bonus.

Tiny, individual light purple or orchid tubular flowers have orange throats and are clustered on upright panicles that are held out like candles all over the shrub. The flowers are very attractive to butterflies, bees, hummingbirds and other nectar drinkers, and are a keystone of the butterfly garden. Long, narrow leaves (6 inches long by 1 1/2 inches wide) are finely toothed along the edges and gray-green above with silver undersides; the shrub is coarse in texture.

It's a fast-growing, deciduous shrub that will require some pruning to keep it fresh each spring, and is best kept within bounds by cutting it to the ground in late winter. In late July, cut the shrub back by half to control size and encourage heavy reblooming.

I'll be looking for the Asian Moon buddleia in garden centers this summer.

Take care of those impatiens

There's a downy mildew pathogen that's wiping out the most popular bedding plant in America -- impatiens. Kathy Kalmowitz, a technician with BASF, said she thinks the disease has simply been carried over in the soil from the previous year. In an article in Greenhouse Grower, she said when the plants aren't cleaned out and the residue is left to rot, the spores will overwinter. So when the crop is replanted, the crop is coming into contact with those spores.

"The key is for consumers not to plant impatiens where they had impatiens last year. Downies are very host-specific pathogens, meaning this particular downy goes to the impatiens. If you had a snapdragon with downy mildew or a rose with downy mildew, those pathogens would not move to impatiens," Kalmowitz said.

In Europe, Kalmowitz said the issue is epidemic.

"I do believe it's because England went through low years of not paying any attention that they're struggling again. For us, I think it's going to take more than a one-year cycle in the U.S. to clean up our beds. The moral of the story is you have to watch how you plant impatiens. Even with a cover spray in the landscape, you could still get some disease in the newly planted beds. But you certainly can't put new impatiens behind last year's impatiens."

Rain barrel workshop

West Virginia State University Extension Service will hold a workshop on garden irrigation and rain barrel construction and usage from 2 to 3 p.m. Wednesday at the Rock Lake Community Life Center in South Charleston.

"In our current economic climate, we can all stand to find ways to save a little money," says Scott Byars, program leader for agriculture and natural resources. "The ability to capture and use 'free' water is the idea behind this workshop."

Participants will learn how to implement basic garden irrigation systems as well as how to construct their own rain barrels to maximize water conservation practices.

A registration fee of $20 is required. Participants will have the option to purchase the rain barrel system they build in the workshop for an additional $30. Contact the WVSU Extension Service offices at 304-204-4319 to reserve a spot in the workshop.

The Rock Lake Community Life Center is at 801 Lincoln Drive, South Charleston.

Shout out to city crew

I was walking past the municipal parking garage at the foot of the South Side Bridge recently and saw one of our city workers taking a photograph of the beautiful flowerbed he helped to create.

I thanked him for making our city beautiful. We are so fortunate to have the green spaces that soften the hard edges of our downtown.

Reach Sara Busse at sara.bu...@wvgazette.com or 304-348-1249.