Caring for Bougainvillea

Water moderately during the growing season, allowing the top 3–5 cm of compost to dry out between waterings. Bougainvillea tolerates short dry spells better than overwatering; soggy roots quickly lead to leaf drop and root rot. In hot summer weather you may need to water two or three times a week, but always check the compost first. Reduce watering significantly from October onwards as growth slows. Feed monthly from April through July with a high-potassium liquid fertiliser (tomato feed works well) to promote vibrant bracts. Avoid high-nitrogen feeds, which encourage leafy growth at the expense of flowers. Stop feeding by late summer to let the plant harden off before winter. Overwintering is critical. Before the first frosts—usually late September or October—move your bougainvillea into a frost-free space: a cool conservatory, greenhouse, or bright porch kept at 5–10°C is ideal. It will drop some or most of its leaves; this is normal. Keep the compost barely moist over winter, watering sparingly perhaps once every two to three weeks. Too much water in cool conditions invites fungal problems. Return the plant outdoors only after the last frost in May. Bougainvillea is generally pest-free outdoors, but watch for aphids on soft new growth in spring and glasshouse whitefly if overwintered in a warm conservatory. Treat with insecticidal soap if needed. Leaf drop is usually caused by overwatering, cold draughts, or moving the pot; keep conditions stable. Repot every two to three years in spring, moving up one pot size only when visibly root-bound.