Diarmuid Gavin: Shoots of recovery
How to help your garden recover from the snow storm
We are just emerging from what was a once-in-30-years snowstorm. Last week, as soon as I'd finished planting a hundred or so ferns and perennials in the shade of a newly transplanted Japanese maple, the snow began to drift down. True to the forecasters' warnings, the drift became a deluge, temperatures plummeted, and I woke up the following morning to a white blanket.
We'd hoped that winter was over, all the vital signs were there - warming soils, plenty of little bulbs popping up and longer daylight hours - but on this small island we can never be sure. It has been known to snow as late as May.
Our natural environment, and the plants we grow, are actually quite resilient. But what damage did the sudden change in temperature and the weight of the snow do? And as the thaw sets in, what do we need to do to help along our shocked or damaged plots?
My first job will be to cast an eye over the planting I'd recently completed. Newly planted specimens will often lift themselves from the soil surface if there is a hard frost straight after planting. Check them regularly and carefully re-firm the ground around them to ensure their roots will always be in contact with the soil.
When soil becomes frozen, even hardy plants that we regard as toughies can suffer as the cold roots may be unable to take up water, so plants can die from lack of moisture.
Damage will have been done to plants but many of them will get over it. The water in some plant cells will have frozen and burst the cell walls. These damaged plants are easy to spot as their foliage becomes limp, maybe even blackened.
Foliage on evergreen plants can turn brown and the leaves of tender plants can take on an insipid, translucent appearance. To prevent further die-back and encourage plants to produce fresh, new shoots, cut back frosted growth in spring to a healthy, new bud.
If we are to suffer more late snows or even frosts into April and May, a lot of damage can be done to new soft emerging shoots and buds and flowers. If you see damaged foliage, give it a while before taking any radical action. Nature has a great way of sorting itself out and, rather than lop off burnt fronds, leaving them may help to protect the fresh emerging growth. Feed damaged plants with a balanced fertiliser (one with equal amounts of nitrogen, phosphorus and potassium) to encourage strong, healthy growth.
An area of the garden that suffers through the snows is your lawn. If you like to maintain a pristine lawn, rather than a rough and ready football space for your children, try to avoid walking on it as your weight will cause damage. Wait for it to thaw completely. Be aware, though, that too much maintenance or remedial action before a full thaw will cause more damage.
Once the area is dry, use a spring-tine rake to clear debris and thatch. If the lawn is very compacted, use an aerator to take up plugs of soil and brush in horticultural sand to aid drainage. In another month, feed the lawn to toughen up the roots and green the foliage.
Your preparation for winter can help mitigate frost and snow damage. So, how could you have planned better for a harsh winter?
An autumnal mulching the ground around hardy species is a good idea. It stops the roots freezing and allows the plant to continue to drink. In anticipation of heavy frosts or snows, it may be worth wrapping less hardy species. Plants such as soft tree ferns (Dicksonia antarctica), the less hardy palms and bananas can be wrapped. For Dicksonias, place some straw into the crown of the fern, not packing too tightly so new emerging fronds will not be damaged. Insulate the trunks of tree ferns, palms and bananas by wrapping in layers of fleece or hessian stuffed with straw.
If snow settles on unprotected fronds of ferns or palms, shake it off gently with a yard brush. If a branch has broken due the weight of snow or through being lashed by a windy storm, make a clean cut at an angle, about inch from the trunk to allow it heal faster, rather than leaving a jagged tear.
Remember that pots and containers may also be vulnerable to freezing and breaking. If you've had warning of some impending extreme cold and you can manage to move your pots, shift them into a protected space, even an enclosed garage.