By Molly Day
All the Dirt on Gardening
Bottlebrush Buckeye, Aesculus parviflora, is a shrub that gardeners remember once they see it in bloom. It has large leaves on a 6-foot-tall and wide woody plant. The white flower panicles, 1 foot long, stand up like huge candles. The tiny, individual flowers on the panicles are tubular with red anthers and pink filaments.
And, best of all, it is a native that thrives in partial to full shade. In fact, the leaves scorch in full southern sun, making it perfect for under trees.
Typical of chestnuts, the leaves are large, dark green, and palmate with five to seven leaflets.
The plants are difficult to find in stores and even more difficult to start from seed. We found ours at the Fayetteville farmers’ market. The seller said he grows them by layering lower branches until they make roots. The suckers can also be removed from a plant, potted for a year, and then planted into the garden.
Bottlebrush Buckeye resists most bugs and diseases, tolerates soil with pH from 5.5 to 7.5, and can grow in clay soil. It is cold hardy in Zones 4 to 8.
In the fall, the leaves are yellow and brown with green splashes. The first freeze will make the leaves fall. The seed pods containing (poisonous) nuts that follow the flowers are similar to the ones found on buckeye trees (horsechestnut, Aesculus hippocastanum) and resemble small brown pears.
The fall color of this plant is featured on the cover of Dirr’s “Manual of Woody Landscape Plants.” Dirr’s appreciation is expressed in the text, “Excellent plant for massing, clumping or placing in shrub borders ... even if it didn’t flower it would be a superb shrub for foliage effect.” Under the Flowers heading he continues, “In my mind, it is one of the handsomest of all native southeastern flowering shrubs.”
When you consider where to plant Bottlebrush Buckeye shrubs, remember that they start out growing slowly but mature to 6 feet wide and then start suckering or sending out shoots at a distance from the parent plant.
Specimens have been reported to grow 12 feet tall and 20 feet across. Use them to fill a large, sloping corner shaded by a fence or place them in a woodland garden under deciduous trees. They also are good for underneath power lines because they stay low enough to avoid problems.
Bottlebrush Buckeye needs to be watered during the first summer and any periods of drought. Fertilize it in the late fall. No pruning is required except for any optional shaping. It is a good idea to keep the shrubs mulched with something acidic and organic such as pine needles or shredded tree bark.
Missouri Botanical Garden’s list of plants for Oklahoma provides growing advice, too. It says that Bottlebrush Buckeye is highly recommended if you are willing to follow the planting and maintenance rules:
“This Buckeye requires moist organic soils that also drain well. It needs to be protected from drying southwest summer winds. It requires shade on summer afternoons; planting under a large shade tree is ideal. It should be watered thoroughly during periods of summer heat and drought. This is not a ‘plant it and forget it’ shrub. Give it what it needs, however, and you will be rewarded with a true garden ‘aristocrat.’ The early summer blooms are spectacular. The fall color is a rich, butter yellow.”
There is a later blooming variety called Aesculus parviflora var serotina or Rogers. If you plant one native and one hybrid, the bloom season would last quite a bit longer. Bottlebrush Buckeye Rogers is an even larger plant with 30-inch flower stems.