Tough Plants for the Irish Climate

The last couple of years have not been easy on Irish gardens. Plants that have grown happily for the last few decades were killed by the cold, crushed by the snow or had their leaves burned off in late spring storms. People are now more aware than ever that when choosing plants for their garden, hardiness is an important issue. And rightly so - nothing is more depressing than seeing plants die.

Hardy shrub for Ireland - Euonymus europaeus / Spindle Silver Birch tree, Connemara

Ireland is generally described as having a 'mild' climate, but the last couple of winters have disproved this, with temperatures staying as low as -15 degrees centigrade over several days. On top of that, we have had sporadic bursts of cold, or cold drying winds later in the year, just when new leaves were emerging. Generally tough plants such as Olearia, Escallonia, Cordyline and Griselinia were either killed or severly knocked back this year. Even Fuchsia, a Chilean plant which is by now a staple of many Irish hedgerows, was brought down to ground level - and in some places killed entirely.

In Ireland, it's not just cold hardiness that needs to be taken into account when choosing plants for your garden. It is also hardiness to wind, hardiness to salty air and hardiness to late frosts. Many of our popular garden plants come from places much colder than ours, like Japan, China, northern America and central Europe. These include shrubby species such as Hydrangea, Camellia, Japanese maples and Magnolias, as well as innumerable grasses and perennials. However cold hardy these plants are, they might not be equipped to cope with our windy, coastal climate, our wet winter soils or our late frosts which are more common than in other parts of the world.

Cordylines in snow, Ballycullen, Co Wicklow

The fiirst line of defence: native plants for shelter. If you want to be very sure that your plants will make it through the coming winters, there is no better choice than native plants. 'Native' means plants that have been growing in Ireland for thousands of years, that are completely indigenous to this landscape. This includes our common hedgerow species such as Hawthorn, Blackthorn, Holly, Spindle and so on. It includes magnificent trees such as Oak, Ash and cots pine, medium-sized trees such as Birch, Alder, Rowan and Hazel and a whole tapestry of grasses, flowering plants and climbers. These are the types of plants that should form our garden boundaries and be the first line of defence against the elements. They can also be used to create a milder climate around and under them, and many of Ireland's gardens are surrounded by shelterbelts of native plants.

Cold-hardy but wind-sensitive plants nearer the house. Using plants around the boundaries creates a better growing environment within your garden. A combination of deciduous and evergreen plants also makes better shelter than a solid evergreen wall. By combining a number of species, you also lessen the risk of losing the shelter in its entirely should one species be badly hit. Within this shelter, you can then grow more sensitive plants nearer to your house. Hardy ornamental plants that were almost unaffected over the last couple of winters include Hydrangea, Cherry, Rhododendron, Magnolia and Roses. Climbers such as Virginia creeper, Honeysuckle,climbing hydrangea and rambling roses are all exceptionally cold hardy. Many of the bamboos grown in Ireland are also exceptionally hardy. However, some are invasive - such as Pseudosassa - and others resent strong winds. Hardy bamboos, which can cope with some wind without getting ragged, include Phyllostachys vivax, Phyllostachys bissettii and Fargesia robusta. These elegant bamboos are useful for the gardener in that they provide canes. They are most elegant in the snow and can provide excellent screening.

Hardy perennial plants for Irish Gardens - teasel is a good example

Tough perennial plants. For colour in the garden, perennials come back year after year and provide many months of blooming. Old-fashiopned favourites such as Catmint (Nepeta), Bergamot (Monarda), Geraniums, Asters, Paeonies and Roses are just some of the many reliable and hardy plants that can withstand the worst of the weather. It's worth bearing in mind the soil type too - most plants prefer free-draining soil. In other words, it can be moist but not water-logged. A good layer of mulch such as leaf-mould, straw or bark protects roots from the extremes of the weather and can prevent plants from being killed by the cold.

Five hardy trees for shelter:

Holly - Ilex aquifolium

Hawthorn - Crataegus monogyna

Scots pine - Pinus sylvestris

Oak - Quercus robur or Quercus petraea

Elder - Sambucus nigra

Five hardy ornamental shrubs:

Hydrangea arborescens - Hydrangea

Mock orange - Philadelphus

Spiraea

Osmanthus

Rose

Five hardy ornamental smaller trees:

Magnolia

Mespilus - Amelanchier

Japanese maple, Field maple - Acer

Dogwood trees - Cornus

Birch - Betula

For detailed lists on what plants grows where, see our Plants for Places page.