Ilex aquifolium - Holly

Holly is perhaps our most beautiful native broadleaved evergreen tree. A mature tree in woodland is a fine sight, particularly in winter, when its stately smooth grey trunk and gleaming leaves stand out well against the leafless branches of other trees. It is equally good as a garden ornamental or an evergreen hedge. It has good conservation value, and both the leaves and the scarlet berries are a potent symbol of Christmas.

Site and soil

Holly will do well in any well-drained soil. It copes well with both shade, exposed sites and pollution.

Height and spread

Below are the approximate stages of growth, assuming sited in suitable conditions for this species;

After 10 years: 4m x 2m
After 20 years: 6m x 3m

Leaf and bark

The leaves are elliptic, glossy, leathery dark green, and with wavy, spiny margins. Older leaves at the top of the tree sometimes become smoother and without spines. They are evergreen, although a proportion of leaves are shed in summer. The bark is very smooth and grey.

Flower, seed and fruit

The small white cup-shaped flowers are borne in clusters in the leaf axils in May. The flowers are dioecious, that is male and female flowers are found on separate plants. Only female hollies bear berries, and then only if there is a male holly nearby to pollinate it. The flowers are followed by the berries, which ripen to red by November. When bought in quantity there is a good chance both sexes will be represented.

Uses

Holly makes a good specimen tree in woodlands and gardens. It is also an excellent formal evergreen hedge, which because it is very dense and spiny, is both intruder and stock-proof.

Its tough leaves are wind-proof, and it can also be left unclipped to form an informal wind-break. It makes very good topiary shapes of all kinds.

The wood is very hard and dense and is used for making mathematical instruments, printing blocks, walking sticks and inlays on furniture. It is much prized by wood-turners, and in the past was used to make Tunbridge Ware. Birdlime was once made from the fermented bark and spread on branches to catch birds as they came into roost.

The berries are strongly purgative, and it was once used medicinally. It resists Honey Fungus well, and is often recommended as a replacement for plants which have been killed by the disease.

Rabbits love the young wood and bark, so plants must be protected from them for the first few years after planting. Holly is said to protect against both witchcraft and lightning, and was traditionally planted near houses for this reason.

Wildlife

Insects pollinate the flowers, and a number of butterflies, including the Holly Blue lay their eggs on the leaves. Because it is dense and evergreen, holly provides good shelter and nesting sites for birds. Many species of birds eat the berries. The wood is very strong, and the tree is seldom damaged by heavy snowfall in severe winters.