Common Holly Ilex Aquifolium
ILEX AQUIFOLIUM – Common Holly
Often associated with Christmas decorations, holly is one of Britain's few native evergreen trees. Its distinctive spiny leaves protect birds from predators while allowing them to feed on its bright red berries.
Left untrimmed, a mature holly tree will grow to 20m (65ft), although many are much smaller and more shrub-like. The dense foliage of spiky protective leaves and its easily trimmed shape means that holly lends itself perfectly to creating evergreen hedges.
Where to grow
It is a truly hardy tree, capable of surviving in most conditions except where it is extremely wet. Large circular groves of holly trees tend to form in woodland as they cast dense shade and will spread by layering.
Did you know?
Most hollies are dioecious, meaning they have separate male and female plants. The pink-white flowers appear in May and pollination is generally carried out by bees and other insects. The berries emerge around November but only on the female plant.
- Mature height
- Large - 15-20 metres
- Shrub Multi-Stem
- Growth rate
- Soil type
- Light sandy
- Sun levels
- All Sun levels
- Difficulty/hard to grow
- Season of interest
- Flower colour
- Flowering type
- Flowering month
- Berries/fruit colour
- Evergreen Hedge
- Berrying Hedge
- Good at altitude
- Parkland Tree
- Garden Tree
- Small garden Tree
- City/Urban Sites
- Encourages wildlife
- Bird Food
- Sound Barrier
- Flower Arranging
Pruning Ilex Aquifolium
Ilex aquifolium can be pruned to be kept as a hedge, or left to develop into a large tree. When establishing, prune vigorous shoots that are going to spoil the balance and outline. It is especially important to prune competing leaders if you want a tree with good symmetry.
Ilex aquifolium can tolerate hard pruning, however clipping annually is the best way to grow a dense evergreen screen.
What time of year should I prune? Pruning is best done in summer
For the continued healthy growth of your trees, shrubs or hedging it is vital that you follow the advice below.
The main reason that plants die within 12 months of having been planted is lack of water. It is essential throughout the spring and summer, to give a heavy enough watering to enable the water to penetrate right down to the deepest root level of the tree. In hot dry spells give the equivalent of 2 bucketfuls every three days.
One of the most common causes of lack of water is competition from grass. When trees are first establishing, the grass roots would be at the same level as the tree roots and are far more efficient at taking up water and thus choke the tree. It is vital for 3 years after planting that your tree or hedge has a circle or strip one metre wide completely free of grass. The way to eliminate grass in order of effectiveness is:
- Spray off the grass with a glyphosate based weed killer such as Roundup. Apply each year for the first 3 years. It is best applied when the tree is dormant as it is absorbed through green leaves and kills the plant off at the roots.
- Firmly fit a mulch mat around the base of the tree by tucking the edges into the soil and put a thick layer of bark mulch on top of this. This can be done after the initial spraying with glyphosate and should avoid the need for further spraying.
Mowing or strimming is NOT an answer to the problem. Each time you mow, the grass will grow back more vigorously and strimming invariably leads to lacerated trunks.
If trees are not correctly secured they will rock in the planting pit. Roots not firmly in contact with the soil are unable to take up moisture and nutrients, resulting in die back or death of the tree. Check, particularly after windy weather, that stakes are still solidly in the ground keeping the base of the trunk firm. The purpose of the stakes is to anchor the roots. Flexing in the wind, higher up the trunk, is not necessarily a problem if the roots are firm.
Bellow is list of the correct system to use to secure your trees.
- 40/60, 60/80, 80/100 whips - Unless rabbit/deer problem no need to stake.
- 100/125, 125/150 1.2m Cane and Easi tie.
- 150/175 1.2m square stake and a buckle tie and spacer.
- 175/250, 6/8, 8/10 15L 1.65 Tree stake and a buckle tie and spacer.
- All larger trees. 2 x 1.65 Tree stake and cross rail with 38mm cushion spacer and 1m of 38mm strapping.
Always use our recommended tree ties or strapping. These are designed and manufactured with the correct amount of give to hold the tree firm without strangling it. They should be checked at the end of each growing season for adjustment as the trunk thickens. Non proprietary materials such as baler twine will cut into the bark and should not be used.
Protection from Animal Damage
Rabbits, deer, sheep, cattle and horses can all potentially damage trees. Ask us for advice on the most appropriate guards for your trees or hedge. Squirrels are also a terrible pest when trees get to about 20ft tall but there is no protection available.