Irish ivy

Irish ivy: how do you recognise it?

Habit

Evergreen climber with aerial roots, up to 10 m tall and 5 m wide. Without support it creeps over the ground as ground cover.

Leaves

Large, leathery and glossy dark green, with three to five shallow lobes; clearly larger than those of common ivy.

Flowering shoots

At the top, where it can climb no further, it forms bushy shoots with unlobed, diamond-shaped leaves. Only these shoots flower.

Flowers

Rounded clusters of small, yellow-green flowers full of nectar, in September–November.

Fruit

Black berries in clusters, ripe in late winter and early spring.

Flowering: September–November · Plants: March–April and September–October · Pruning: February and September

Why grow it?

• Quickly covers a bare wall, fence or garden wall and stays green all year.
• One of the best ground covers for deep shade, for example under trees.
• Flowers in September–November, when almost nothing else does: a last source of nectar for bees, hoverflies and butterflies.
• The black berries ripen in late winter, just when birds find little other food.
• A dense ivy wall offers nesting sites and shelter for birds and insects.

Irish ivy: where does it grow best?

• Sun, partial shade or deep shade: it grows anywhere, but the leaves look best in shade.
• Almost any soil that is not waterlogged: sand, loam or clay, acid to chalky.
• Moist; once established it copes well with drought, even under trees.
• Choose a wall in good condition, without loose mortar, and keep it away from timber cladding and gutters.
• Against a wall, plant one per metre; as ground cover, allow 3–4 plants per m².

Light

Sun, partial shade and shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

10 m tall, 5 m wide

Hardiness

Hardy (to -20 °C)

Goes well with

• Ferns: Together they make an atmospheric green corner in the shade.
• Snowdrop: White among the dark green in February.
• Daffodil: Pushes up through the ivy carpet in spring.
• Lenten rose: Flowers in late winter in the same shade.
• Hosta: Large, lighter leaves against the dark ivy foliage.

Irish ivy: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or September–October, when the soil is moist but not frozen.
2. Dig a hole a little larger than the pot and mix in some compost. Against a wall, plant 30–40 cm out from it.
3. Set the plant at the same depth as in the pot. Lean the shoots against the wall or tie them to a cane resting against it.
4. As ground cover, spread the shoots over the soil and pin them down with a few hooks; they will root faster.
5. Firm in and water thoroughly straight away.
6. Mulch between the plants until they cover the ground; this keeps weeds down.

Care

Watering

Weekly in dry weather in the first year, especially against a wall or under trees. After that it looks after itself.

Feeding

Usually not needed. A layer of compost in spring helps a young planting get going.

Training

Only new shoots cling. Guide the young shoots towards the wall for the first few months.

Checking

Check every year that it is not creeping into gutters, under roof tiles or behind downpipes.

Weeding

With ground cover, weed between the plants for the first two years; after that the carpet closes.

Tip: Every February, cut it out of gutters, off roof tiles and away from windows, and never rip shoots off the wall: cut them free and let them dry out.

Irish ivy: when to prune it?

Pruning months: February and September.

When: In February, before the nesting season, and if needed again in September, once the young birds have fledged.

How:

• Cut shoots out of gutters, off roof tiles and away from windows, doors and air vents. Keep a strip of 30–50 cm clear.
• Do not rip shoots off the wall: cut them free, let them dry out and brush off the aerial roots later.
• In February, ground cover can be trimmed short with hedge shears or a mower on its highest setting.
• At the top, leave the bushy flowering shoots wherever possible: that is where the flowers and berries come.

Caution: Wear gloves and long sleeves: the sap can irritate the skin. Ivy is a favourite nesting site, so do not prune during the nesting season.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

From June to September: 10–15 cm pieces of young climbing shoots, in cutting compost or even a glass of water. They root very easily.

Rooted shoots

Trailing shoots root by themselves. In spring or autumn, cut off rooted pieces and replant them.

Tree ivy

Cuttings from the flowering shoots at the top grow into a small shrub that does not climb but does flower and fruit.

Irish ivy: how does it get through the winter?

Hardy to −20 °C.

• Hardy to about −20 °C and green all winter: no protection needed.
• In hard winters some leaves may brown in bitter wind; it regrows in spring.
• The berries ripen from January to March and are a welcome food source for blackbirds, thrushes and wood pigeons.
• In winter an ivy wall shelters birds and overwintering insects.

Diseases and pests

• Wall damage: On a wall with loose joints or soft lime mortar, the aerial roots grow into cracks. On sound brickwork this is rarely a problem; have old walls checked first.
• Gutters and roofs: Shoots creep into gutters, under roof tiles and behind woodwork. Cut it back below the roofline every year.
• Too heavy: On an old fence or a weak tree, a thick layer of ivy catches a lot of wind. Thin it or cut it back in time.
• Slow start: In the first year it hardly seems to grow, because it is making roots first. Be patient: after that it goes fast.

Through the year

• January: The berries ripen and turn black. Resting.
• February: Pruning: clear gutters, roof tiles and windows before the nesting season. Trim ground cover short.
• March: Planting. Black berries for the birds.
• April: Planting. Guide young shoots to the wall.
• June: Take cuttings. Water young plants in dry weather.
• August: Take cuttings. Water in dry weather.
• September: Planting. Another trim around windows and gutters. Flowering begins.
• October: Planting. Full flower: the wall hums with bees and hoverflies.
• November: Last flowers. Leave the flowering shoots for the berries.
• December: Green in winter. Shelter for birds.

Edible and useful

Not edible. Ivy leaves and berries are poisonous: they contain saponins, which cause vomiting, stomach ache and diarrhoea if eaten, in children as well as in dogs and cats. The black berries ripen in late winter and early spring, when there are few other berries about, and on a wall or fence they sometimes hang within a child’s reach. The sap can irritate the skin, causing redness, itching and sometimes blisters, especially in people who often prune with bare hands: wear gloves and long sleeves, and wash your hands afterwards. Clear up the clippings where children or pets play. Birds, however, eat the berries without harm, and the late flowers are important for bees. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Birds

Berries, seeds or insects as food, or a place to nest.

Did you know?

• Ivy is not a parasite: its aerial roots are only for clinging. It takes water and food from the soil like any other plant.
• The ivy bee, a wild bee seen more and more often in Belgium, collects pollen almost only from ivy and flies in September–October, exactly when ivy flowers.
• Ivy has two faces: climbing shoots with lobed leaves and, at the top, bushy flowering shoots with unlobed leaves. Cuttings from those flowering shoots usually no longer climb.