The bottlebrush plant is so named for its large, tall (up to 12 inches) spikes of flowers that resemble a bottle-cleaning brush. Scientifically classified as Aesculus parviflora, the bottlebrush buckeye is a slow-growing but attractive shrub native to the United States. This hardy plant is easy to grow once established, in part due to the fact that it is resistant to serious insect pests and diseases, according to information published by the University of Florida.
Plant the bottle brush in a location that has at least some shade. A site that has morning sun followed by afternoon shade is best. In warmer climates, this shrub can be planted in full shade. These plants grow best in cool, moist conditions, according to the University of Florida.
Plant your bottle brush in soil that remains continually moist, but not overly soggy or muddy. While the plant can tolerate occasional flooding, too much water will cause root rot, which is a fungal disease. Although the bottlebrush buckeye can tolerate heavy clay soils, according to the University of Florida, it performs best in rich, loamy soil.
Space individual bushes at least 36 to 60 inches apart, as they can get as large as 15 feet wide. Bottle brush shrubs should not be pruned, according to the University of Florida, as this ruins the plant's natural shape. To plant, dig a hole as wide and deep as the root ball. Backfill with the removed soil, water well and add a layer of mulch to preserve moisture and stifle weed growth.
Fertilize your bottle brush each spring with a balanced (10-10-10) fertilizer formulated for flowering shrubs. Follow the directions according to the information on the label as per the age and size of your bush.