Turkish mullein in April: monthly care

Verbascum bombyciferum thrives in full sun and well-drained soil, making it ideal for gravel gardens, sunny borders, and Mediterranean-style plantings. It tolerates sandy, loamy, and chalky soils but will not perform well in heavy clay or waterlogged ground. If your soil is prone to sitting wet, dig in plenty of grit or coarse sand before planting to improve drainage. Plant young verbascum in March, April, or May for establishment before summer, or in September and October to give roots time to settle before winter. Space plants 50 cm apart to allow for their eventual spread of 40–60 cm and to ensure good air circulation around the silvery foliage. Dig a hole slightly larger than the root ball, place the plant so the crown sits level with the surrounding soil, and backfill with the excavated soil mixed with a little compost if your ground is very poor. Water in thoroughly after planting to settle the roots, but thereafter verbascum needs very little irrigation thanks to its low water requirement. Avoid planting too deeply, as a buried crown can rot in damp conditions. A light mulch of gravel or grit around the base helps suppress weeds and keeps the neck of the plant dry, which is especially useful over winter. Staking is rarely necessary despite the plant's impressive height of 120–200 cm, as the sturdy flower spikes are naturally robust. Choose a sheltered spot if your garden is very exposed to strong winds, though the plant is generally tough once established.

Verbascum bombyciferum is a low-maintenance plant once established, requiring minimal intervention throughout the year. Its low water need means you should water only during prolonged dry spells in the first growing season; established plants are drought-tolerant and rarely need supplementary watering. Overwatering or planting in poorly drained soil is the most common cause of failure, leading to root rot and crown decay. Feed lightly in April or May with a general-purpose granular fertiliser or a handful of blood, fish, and bone scattered around the base of the plant. Avoid high-nitrogen feeds, which promote lush foliage at the expense of flowers and can make plants more prone to flopping. Verbascum grows naturally in poor, stony soils and does not need rich feeding. Mulch with gravel or grit rather than organic matter. A 2–3 cm layer around the crown improves drainage, suppresses weeds, and keeps the neck of the plant dry over winter, which is critical for survival in our damp climate. Avoid bark or compost mulches, which retain moisture. Verbascum bombyciferum is fully hardy in zones 5–9 and needs no winter protection in temperate Europe. The silvery, felted leaves are attractive through winter, though they may look tatted after heavy rain or snow. Remove any rotting foliage in late winter to reduce the risk of fungal disease. Pests are rarely a problem, but verbascum moth caterpillars can occasionally strip foliage in summer. Check plants in June and July and remove caterpillars by hand if you spot them. Powdery mildew may appear in dry summers on older leaves but is rarely serious.