Rowan in May: monthly care

Rowan is a low-maintenance tree once established. Water young trees regularly during their first two years, particularly from late spring through summer, giving a thorough soak every week or ten days in dry weather. Established rowans have moderate water needs and usually manage on rainfall alone, though prolonged drought in summer may warrant occasional deep watering. Avoid waterlogging, as rowans dislike sitting in saturated soil. Feed in March or April by sprinkling a general-purpose granular fertiliser, such as blood, fish and bone or Growmore, in a circle around the drip line (the outer edge of the canopy). Use roughly 70–100 grams per square metre and lightly fork it into the soil surface, then water in if rain isn't forecast. Mature trees in reasonable soil rarely need feeding, but a spring application supports healthy foliage and the abundant white flowers that appear in late spring and early summer, followed by the bright orange-red berries in autumn. Rowan is fully hardy to zone 2a and needs no winter protection in temperate Europe. Refresh the mulch layer each autumn to suppress weeds and conserve moisture. Watch for aphids on young shoots in spring; a strong jet of water usually dislodges them, or use an insecticidal soap if numbers are high. Fireblight, a bacterial disease, can occasionally affect rowans, causing blackened, scorched-looking shoots; prune out infected material immediately, cutting well below the damage, and disinfect tools between cuts. Silverleaf fungus is less common but recognisable by a silvery sheen on leaves; again, prune out affected branches promptly and burn or bin the prunings.