A few years ago, a friend and I were on a garden tour in Ontario, Canada, and we made a stop at the butterfly conservatory at Niagara Falls.
This was my first trip to a butterfly house, and even though I've been to several others since in various places, including Chicago and Cleveland, that first visit left me with the best memories and the greatest impression.
As my friend and I walked through the simulated tropical forest, laden with nectar stands, fruit hanging from trees, and rippling ponds as a water source, several butterflies landed on our shoulders, heads and arms as if to examine us just as closely as we were examining them. One butterfly in particular, a large, blue-winged beauty, sat on my shoulder for several minutes as I traversed the winding path through the misty garden.
I thought at first I'd made a new friend, but before long, he (or she) was gone, off to find a sweet meal from a fragrant blossom.
It wasn't long afterward that I bought my first butterfly bush for my garden. Not to be confused with butterfly weed, which is also an attractive plant for butterflies, butterfly bush, or Buddleia davidii, was to me, even more attractive. Butterfly weed (Asclepias tuberosa), produces bright orange flowers, which I love, but didn't fit into my garden's color scheme.
Instead, I chose Buddleia davidii "Black Knight," a deep purple variety that, at the time, was fairly new on the scene. Every spring my butterfly bush rose up from the earth, growing so quickly that by mid-summer, the plant was taller than I am and was filled with long, narrow stems, called infloresences, filled with hundreds of tiny blossoms. I planted it, and the butterflies came, as did the bees, hummingbirds and hummingbird moths.
And then, one summer about two years ago, it didn't return. Like most perennials, butterfly bush will eventually simply tire out. Unlike many perennials, however, Buddleia can't be divided to create additional plants due to its woody trunk and root system. It can safely be called a shrub rather than a herbaceous perennial, and splitting the trunk would likely kill the plant.
I didn't replace it right away because I've been thinking of a different spot for more butterfly bushes in the meantime, but last spring, I happened to come across a packet of seeds for "Black Knight" Buddleia. Could I grow this shrub from seed? It was worth a shot.
I filled a large container with soil mix and sprinkled the seeds on top. I pushed the container to the back of the bench and other than regular waterings, basically forgot about it because I really wasn't sure what would happen.
As it turns out, many of the seeds germinated and it wasn't long before the container was filled with small Buddleia seedlings. They grew quite quickly, almost as fast as if they had been there awhile, and I was delighted that now I had not just one, but many Buddleia seedlings to sprinkle throughout the garden.
If there is a good reason for starting plants from seeds, butterfly bush has to be it.
The plants like full to partial sun. Like most plants, it prefers well-drained fertile soil, but this hardy nectar producer has the ability to adapt to poorer soils if that's all you have. (It shouldn't be all you have if you compost, but that's another column).
The shrub grows quickly and can reach 8 feet tall and equally as wide, so be sure to give it ample room. Pinch off spent blossoms to encourage side shooting and more flowers.
I like leaving the dead-looking trunk and branches throughout the winter for snow accumulations and vertical winter interest, but in early spring, it should be pruned back hard to near ground level. The flowers bloom on new wood, which grows from the plant's roots underground. The flower-producing branches grow quickly over one season, so cutting it back in spring won't keep it from blooming like lilac or forsythia.
The hardiness of these shrubs extends north to our zone 5 region, according to the cold hardiness zone map created by the U.S. Department of Agriculture. In the south, it doesn't die back to the ground each winter as it does here, but that's OK because we still get to enjoy it in our gardens. But since we are on the cusp of its hardiness level, we probably should protect the plant's crown in winter with a good coat of mulch or leaves.
"Black Knight" isn't the only variety of butterfly bush. The plant also is available in shades of pale to medium purples and even white and rosy pink. Every garden should have them.
Evanoff is a Master Gardener with The Ohio State University Extension of Trumbull County. She can be reached at firstname.lastname@example.org.