Callistemon Harkness

How to grow Callistemon Harkness

To grow Callistemon Harkness, choose a sunny spot with well-drained soil, as this cultivar thrives in full sun and tolerates a range of soil types, including sandy and clay soils. Before planting, enrich the soil with organic compost to boost nutrients. Water regularly during the first growing season to help establish a deep, resilient root system, then reduce watering once established, as Callistemon are drought-tolerant. Prune lightly after flowering to maintain a neat shape and encourage dense, bushy growth. Fertilise annually in spring with a slow-release, low-phosphorus fertiliser. ‘Harkness’ can tolerate light frosts and coastal conditions, making it a hardy choice for many gardens. Mulching around the base will help retain soil moisture and suppress weeds, but keep mulch away from the stem to prevent rot.