“Little John” bottle brush (Callistemon citrinus 'Little John') produces brilliant red brush-like flowers in spring and summer, while the evergreen foliage provides year-round interest. This dwarf variety only grows about 3 feet tall, so it works well as a specimen plant in beds or lined up in a row for a low hedge or border. “Little John” grows in U.S. Department of Agriculture plant hardiness zones 8 through 11. Plant it in spring or early summer so it can establish healthy roots before winter.
Choosing a Site
Like most bottle brush shrubs, “Little John” grows well in locations that receive full, all-day sunlight. Select a bed with well-drained soil. It can grow in most soil types but it doesn't tolerate wet or poorly drained areas. Break up the soil before planting to a 12- to 18-inch depth, removing any old roots or large rocks that can block drainage or impede root growth. Mix in a 2- to 4-inch layer of compost with the loosened soil to add drainage and structure to the site before planting. “Little John” matures to a 5-foot width, so avoid placing it too close to large plants or buildings.
Preparing to Plant
If the bed has drainage issues, build up the soil and plant on an 8-inch raised mound to improve drainage. Dig the planting hole to the same depth as the nursery pot but make it twice as wide. Water the soil in the “Little John” pot lightly so the root ball slides out more easily. If you can plant right away, set the pot in a frost-free, sunny location and keep the soil evenly moist until you are ready to plant.
Transplanting the Plant
Planting on an overcast day or in the evening protects the bottle brush from heat and sun stress right after planting. Lift the “Little John” shrub from the pot and set it in the planting hole so it's at the same depth it was growing at in the pot. If any roots encircle the root ball, slice 1 to 2 inches into the root ball with a rubbing alcohol-disinfected knife in two to four spots, cutting from the top to the base of the root ball. This prevents the roots from constricting themselves as they grow. Fill in the hole halfway, and water to settle the soil around the roots. Fill the remainder of the hole with soil and water a second time.
Caring for the Plant
Weekly watering for the first summer after planting helps “Little John” establish a healthy root system, but it will rarely require watering once established in the second year. Provide about one inch of water weekly if there isn't comparable rainfall. Avoid overwatering that results in wet, soggy soil because “Little John” is prone to root rot in wet conditions. Apply a general purpose fertilizer in early spring before the plant shows new growth. Pruning isn't usually necessary the first year, but you can trim off any suckers that grow from the base of the trunk if you want to maintain the "Little John” as a single-trunk specimen.