Holly in March: monthly care

Holly (Ilex aquifolium) is best planted during its dormant season: October and November in autumn, or March in early spring. Choose a site in full sun, partial shade, or even full shade—holly is remarkably tolerant of different light levels, though berry production is usually best in brighter positions. It adapts to a wide range of soils, including loam, clay, and sandy ground, provided drainage is reasonable. Avoid waterlogged sites. Before planting, dig a hole roughly twice the width of the root ball and the same depth. Break up compacted soil at the base and sides of the hole to encourage roots to spread. If your soil is very heavy clay, fork in some grit or coarse organic matter to improve drainage. For sandy soils, incorporate well-rotted compost or manure to boost moisture retention and fertility. Set the plant so the top of the root ball sits level with the surrounding soil—planting too deep can lead to stem rot. Backfill with the excavated soil, firming gently as you go to eliminate air pockets. Water thoroughly after planting, even if the soil feels damp, to settle roots in. If you're planting holly as a hedge, space plants 300 cm apart for a traditional screen, or closer (around 60–90 cm) for a denser, more formal hedge that will require regular clipping. After planting, apply a 5–8 cm layer of mulch (bark chips or well-rotted compost) around the base, keeping it clear of the stem. This conserves moisture and suppresses weeds while the plant establishes. Stake young standards if the site is exposed, using a low stake and flexible tie.

Holly is a low-maintenance evergreen once established. Water newly planted specimens regularly during their first growing season, especially in dry spells, to help roots settle in. After that, holly is quite drought-tolerant and usually manages on rainfall alone. In prolonged summer drought, give established plants a deep soak every couple of weeks; container-grown hollies need more frequent watering year-round. Feed in March or April with a balanced slow-release fertiliser (such as blood, fish and bone or a general shrub feed) scattered around the root zone and lightly forked in. Avoid high-nitrogen feeds, which promote soft, sappy growth at the expense of berries. A top-up of mulch in spring—well-rotted compost or bark—helps retain moisture and adds organic matter as it breaks down. Holly is generally trouble-free, but watch for holly leaf miner, a small fly whose larvae create yellowish-brown blotches and winding tunnels in the leaves. Pick off and destroy affected leaves if the infestation is light; severe cases may warrant a systemic insecticide in late spring when adults are active. Occasionally, holly can suffer from phytophthora root rot in poorly drained soils—symptoms include yellowing foliage and dieback. Improving drainage is the only real remedy. Holly is fully hardy in zones 6a–9b and needs no winter protection. Its evergreen foliage provides year-round structure and shelter for wildlife. Remove any fallen leaves from beneath the plant in autumn to reduce the risk of fungal disease, and check for broken branches after winter storms.