The bottlebrush plant (Aesculus parviflora) is a variety of buckeye that gardeners love for its 12-inch long white or red flowers. The deciduous shrub also features attractive oblong green leaves that turn golden in the fall. The spreading shrub is native to the United States and can reach a maximum height and width of 10 to 15 feet. Once established, the bottlebrush plant only requires basic culture to thrive.
The bottlebrush buckeye is native to the southeastern part of the United States but thrives in USD Hardiness Zones 4 through 8, which are temperate zones with relatively mild winters and summers.
Bottlebrush shrubs grow best in the dappled shade of a deciduous tree or other tall plant. The plant can be placed in full sunlight in the cooler growing zones. If your summers are very hot, place the bottlebrush where it will receive morning sunlight followed by afternoon shade.
Provide moist but well-draining soil for your bottlebrush shrub. This plant will tolerate drought conditions better than very wet, boggy soil. The bottlebrush also requires high amounts of nutrients, so amend your soil with organic matter to help the plant become established and grow vigorously. The soil should be neutral or slightly acidic.
Bottlebrush, while somewhat drought tolerant, will need to be watered one or two times per week during the growing season, depending on the weather. Let the top few inches of soil dry out before watering. Mulch the shrub with 3 or 4 inches of straw to retain moisture and stifle the growth of suckers.
The best fertilizer for a bottlebrush plant is a balanced (8-8-8), slow-release, all-purpose fertilizer. Apply it in the spring or a month after planting, then again in the winter. Use 1 lb. for every 100 square feet of bottlebrush plantings.
You should prune your shrub to the desired shape after the blooms have faded. Bottlebrushes can be trained on a leader. Watch for suckers and clip them as soon as you see them.
The leaves and especially the seeds of the bottlebrush plant are extremely poisonous and can be fatal if ingested by pets or humans.