The word “bottlebrush” alone should make you want to grow it, but when you consider that the flowers are 4 inches wide and 12 inches long and are produced in huge quantities, it really should make you want to go shopping. If there were a poster child for underused plants however, the bottlebrush buckeye would be the spectacular winner.
The huge, white blossoms and dark green palmate leaves that turn an attractive yellow in the fall make this a plant for all shrub beds. Despite being such a dynamite plant, they are still rare in the marketplace. This native is still not the staple at the garden center. We as gardeners and horticulturists need to do a better job promoting this plant and its cultural requirements.
Botanically speaking, it is known as Aesculus parviflora and is native to Georgia, Florida, Alabama and South Carolina. Don’t fret if your state wasn’t listed. Though it is native to the Southeast, it is cold hardy in zones 4-8.
Choose a site in partial to little shade, especially if you are near the coast or southern edge of the plant zones. Prepare a bed for the bottlebrush buckeye and companion shrubs by incorporating 3 to 4 inches of organic matter and 2 pounds of a 5-10-5 fertilizer per 100 square feet of planting area, tilling deeply.
Don’t skimp on the hole. Dig the planting hole two to three times as wide as the rootball but no deeper. Place the buckeye in the hole and backfill with soil to two-thirds the depth. Tamp the soil and water to settle, add the remaining backfill, repeat the process and apply mulch.
About a month after spring planting, feed with a light application of a slow-release, balanced fertilizer like an 8-8-8 at a rate equaling 1 pound per 100 square feet. Feed established plantings in late winter with the same fertilizer.
Keep suckers pruned as they develop to keep the bottlebrush buckeye confined. Light pruning can be done after blooming, and they will return faithfully after being cut to the ground in winter for a rejuvenation-type pruning. Be sure to keep a good 3- to 4-inch layer of mulch, particularly in the summer. Treat it like an azalea from the standpoint of mulch and moisture.
They reach about 10 to 12 feet tall and as wide and are perfect for the edge of woodland gardens. They are deciduous but don’t let this be detraction, after all this works for spiraea, quince, and forsythia, and it will for the bottlebrush buckeye, too.
At the Coastal Georgia Botanical Gardens in Savannah we are growing ours in what we consider our historical district. It is in close proximity to live oaks, hollies, large oleanders and blooming esperanza. Ours started blooming the first week in June and were a real showstopper.
I subscribe to various periodicals that tell who has what for sale in the wholesale nursery industry, and I assure you they are available to your local garden center. So your next visit, ask them to get you two or three. I promise you will be the envy of the neighborhood.