Conifer care

Conifers are trees with unique scale-like leaves or needles and their seed-bearing cones are easily recognised. They are mostly evergreen and can grow into large, often very fast-growing trees, although there are many dwarf varieites, including many effective groundcover plants. Many conifers make good hedges too. Yew is a conifer with small cones with a fleshly covering. Gingko is also a conifer, but its triangular leaves are clearly different and like yew its cones (on female plants) also have a fleshy covering.

Conifers

Conifers

Quick facts

Group Conifers
Planting time October to April
Height and spread various
Aspect Sun and part shade
Hardiness Fully hardy to tender
Difficulty Easy to difficult

Cultivation notes

Choosing good quality conifers, planting them correctly and looking after them for the first few years are crucial to successful conifer establishment. Large conifers are much harder to establish than smaller ones. This applies equally to trees that are being transplanted as to newly purchased specimens.

Routine maintenance

Feeding: Conifers are not demanding and in most cases annual feeding with 50-100g per sq m (1½-3oz sq yd) of general-purpose fertiliser every late winter will suffice.

Mulching: Conifers benefit from mulching to suppress weeds, provide nutrients, improve soil conditions and conserve moisture. Trees are usually mulched in late winter, after any fertiliser application, to conserve winter moisture reserves in the soil before the spring and summer.

Watering: Although newly planted conifers initially need careful watering, once established they usually need little water.

Reversion and Sporting: Remove reverted shoots promptly.

Suckers: Remove any shoots arising from below grafts or from the roots.

Pruning and training

Unlike other woody plants, conifers need very little pruning, except for where green branches appear in trees with coloured or variegated foliage.

However, it is very common for conifers to get too large for their site. Dwarf conifers in many cases are not actually dwarf but just slow growing and in time will become large and outgrow their space. Although replacement is often best, their size can be controlled to some extent by trimming and pruning.

A few conifers, yew for example and less reliably, Thuja, can be pruned hard and will regrow. Most conifers will not regrow from old wood if you prune into this.

However it is possible to trim the green foliage in the same way you would a hedge leaving a mossy green finish, just make sure you don't prune into the brown dead wood. Once the growing tip is removed conifers will make little upward growth with just a few wispy shoots that are readily trimmed. Conifers may be pruned from spring to late summer. Yew can be pruned into early autumn.

Propagation

Most garden conifers are propagated by semi-ripe or hardwood cuttings. Many trees can be raised from seed. Others can be raised by grafting.

Cultivar Selection

See the RHS Find a Plant for help with selecting suitable conifers for your garden.

Problems

Many larger conifers are large and hard-to-replace features in gardens, and ill health is a worry. Even smaller conifers have an important part to play being long-lived and evergreen garden features.

Brown foliage on conifers can mean a number of problems. Newly planted conifers have their own set of problems. Trees can also suffer attack from pests and diseases such as honey fungus and Phytophthora root rot.


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