Bottlebrush plants get their name from their bristly red flowers that look like a traditional bottle brush. They're popular desert perennials (you need to plant them only once) because they're colorful, inexpensive, low care, drought-resistant, and readily available. The botanical name for bottlebrush (sometimes written bottle brush) is Callistemon. These evergreen shrubs flower mostly in the spring and summer and can be found all over Arizona, Nevada, and New Mexico.
|Common Name||Bottlebrush, Little John|
|Plant Type||Flowering perennial desert shrub|
|Mature Size||Up to 15 feet|
|Sun Exposure||Full sun|
|Soil Type||Any type, well-drained|
|Hardiness Zones||8–11, USA|
How to Grow Bottlebrush Plants
Bottlebrush plants are not the fastest growers, but they come in a variety of sizes, the largest reaching up to 15 feet in height. Dwarf varieties grow up to three feet and make a nice low shrub for under windows or lining walkways and driveways. No matter which type of bottlebrush you choose to plant, they can provide a beautiful distraction to an otherwise dull landscape.
Because of their bright red flowers, they attract nectar-feeding birds like hummingbirds. However, they also appeal to bees and wasps, which is something to consider before planting if you or anyone you live with has a bee sting allergy.
Bottlebrush plants produce the most flowers when planted in full sun. They will tolerate partial shade, but they likely won't produce flowers if planted in full shade.
You can determine the sunniest spot in your yard by making a map of your growing area and recording where the light falls throughout the day. Begin by checking where the sun hits the ground first thing in the morning and then draw a corresponding circle on your map. Repeat this process at noon and then once again in the evening. The section where all the circles overlap is the sunniest location.
While they can survive in most soils, bottlebrush prefers loamy, damp ground. It's especially important that their growing area is properly drained. If your soil is poor or full of clay, you can mix in compost and topsoil before planting. A rototiller may be required for this task if the soil is difficult to loosen by hand.
Bottlebrush plants don't require much water, which is helpful if you live in an area with watering regulations. However, while somewhat drought-resistant, these shrubs will need some sort of water source such as a drip system to remain healthy during long dry spells. They will not survive in locations with standing water, so avoid planting in lower areas of your yard where water may collect.
Temperature and Humidity
Bottlebrush plants can tolerate very high temperatures and prefer low humidity but do not do well in the frost. If freezing temperatures are predicted, the shrubs will benefit from being wrapped with some muslin or a sheet. They will not survive in prolonged temperatures below freezing, so if planted in a zone lower than 8, they will need to be moved inside for the winter.
While not required, applying a low-phosphorous fertilizer in the spring can help bottlebrush flourish throughout the growing season. An additional application after the plant has been pruned can help encourage new growth.
Potting and Repotting
Bottlebrush is versatile in that it can be grown in a range of sizes within pots as well as planted in the ground. The dwarf varieties like "Little John" can be trained and shaped to look like miniature trees that are especially nice when placed on either side of a front door.
Propagating Bottlebrush Plants
If you wish to replicate the features of the parent plant, propagating by cuttings is the optimal technique. Semi-mature wood branches of the shrub produce more offshoots, making them ideal for cuttings.
Varieties of Bottlebrush Plants
There are about 50 species of bottlebrush ranging in size from dwarf bush to tree. Flower heads across all the species are mostly red but they can also come in orange, yellow, green, or white.
Toxicity of Bottlebrush Plants
While bottlebrush plants are not known to be extremely toxic, make sure they stay out of reach of young children and pets as even non-toxic plants can cause vomiting if ingested. They do not cause any skin irritations.
Regardless of which type you plant, these bushes need occasional trimming to be kept looking neat and to enhance next season's blooms. Flowering normally occurs in the spring and early summer but the desert sunshine encourages them to bloom multiple times a year. In order to get the best results, you'll need to trim them when the bright petals fall off.
Common Pests and Diseases
Most issues arise for bottlebrush plants when they are planted in soil that is too wet or if there is too much moisture on the plants themselves. The diseases that can result from overwatering include mildew, fungus growth, and root rot. Preventing these conditions is far preferable to treatment, so if you notice excessive water, it's likely best to move the plant to a new location.