TOP OF THE IVY LEAGUE 
1st June 2009

Ubiquitous it may be but there is always room for ivy in my garden. The native Irish species can be a pest travelling far and wide while behaving like a weed. Its flowers do however provide late nectar for bees and other insects and the late winter berries are welcomed by wildlife.

There are other species and varieties that are better behaved adding evergreen leaf colour to the winter garden while remaining well within their allotted space.

An obvious use is as screening. Ivies are well suited to covering unsightly walls and sheds. The fast growing thin shoots have the ability to adhere to any surface by aerial roots. Care should be taken to prevent the stems penetrating the roof space where they continue to grow making a mess and dislodging roof tiles.

American gardeners are keen to use ivy as ground cover under trees. It is tolerant of shade and dry soil and the glossy evergreen leaves keep down weeds. When it is clipped over in spring ivy remains compact with lots of new growths. The secret of success is to make sure the stems are not allowed to reach the tree trunk and start climbing.
Ivy is not fussy regarding soil or position. It will thrive in any type of soil, dry or wet and being as tough as old boots may be planted in exposed, cold sites in full sun or deep shade.

It has a peculiar habit. The mature plant becomes tree like with thick branches that grow out from the support and this is why in large, sometimes old, trees the trunks and branches disappear under the ivy foliage.

The two main species are the English ivy (Hedera helix) and Irish ivy (Hedera hibernica). Between them there are hundreds of varieties many with beautifully marked foliage. H. helix. ‘Glacier’ only grows to 2 metres in height with small, grey-green leaves marked with pale grey and cream.

My favourite species is Hedera helix f. poetarum sometimes labelled H.h. ‘Poetica Arborea’. Commonly known as the Poet’s ivy it has deep, orange-yellow berries. In Italy the foliage was used to make wreathes for poets.

Reduce the Watering
It is that time of year; summer, school holidays and days away. Who knows, perhaps this year we will have a hot, dry couple of months so that there is something to complain about.

The trouble is that our plants are not conditioned for long periods without water. They are so used to having a constant supply available in the ground that their roots haven’t had to go searching for moisture. When we do get a dry spell they are nowhere near available water at lower levels.

That is when those Mediterranean plants that we usually struggle with such as lavender do best. They love a dry, sun baked soil feeling pretty miserable most years in our soggy ground.

Mulching, before the soil dries out, will help prevent evaporation keeping the upper layer cool and moist. Use bark, gravel, broken slate, home made compost or farmyard manure.
Store water from down pipes in clean barrels or water butts in case there is a hose pipe ban.

Those plants most in need of water will be trees and shrubs that were recently planted especially if they were bare root rather than container grown. Plants in pots dry out quickly. Those on a soil based compost fare better than those grown in a soilless compost. If the compost dries out completely it shrinks away from the edge of the pot. The only way to re-wet it is to plunge the whole thing in water until bubbles stop rising to the surface.

Watering in the evening allows it to penetrate down into the ground before the sun causes evaporation. Watering when the sun is shining may cause leaf scorch and most of it doesn’t reach down to the root zone.

If you are going on holiday ask a gardener to look after the plants. He or she will know what to do.

If we are in for another wet summer then the good news is that your plants will be happy and you will have more time to weed!

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