In the garden: Learn from the cold snap to help plants

The snow and ice that last week’s weather brought was a real eye-opener about what winter is all about. We had almost forgotten what cold was!

We are blessed with a temperate climate in Ireland, with not too many extremes, hot or cold. The last few winters have been relatively mild, with little in the way of low temperatures that impacted movement and day-to-day activity as severely as the cold snap last week did.

We take for granted how mild our winters can be, and while we get more than our fair share of rain and wind, lower temperatures generally come and go pretty quickly.

Walking out into the garden with snow on the ground last week started to make you realise how important vegetation is for shelter and providing refuge from frost.

Similarly, taking a walk out into nature and observing hedgerows and how plants serve the wider environment, and the valuable function that they have for wildlife in the countryside, cannot be underestimated. The snow melts quickly along the base of a south-facing hedgerow or building. Little frost or snow was found under mature trees as the roots and canopy were creating a sheltered microclimate beneath.

Now, if the cold snap went on for longer, this would inevitably change, but in the short-term the presence of vegetation helps greatly to improve shelter and warmth.

The importance of plants cannot be under-estimated in the protection of the soil, habitat creation, and furnishing the landscape with interest and beauty.

What we do in our gardens is a scaled down version of the wider environment, creating shelter for our houses, a place that is pleasant to spend time in, and valuable habitats for insects and other wildlife, particularly during the harsh winter months.

It has been a few years since we had snow in the garden, and it fell thick and fast last week, taking its toll on some plants in the garden.

A very columnar pittosporum became splayed and unrecognisable in a few hours, but thankfully the snow fell off promptly and the shrub regained its elegant shape quickly, because heavy snow can break branches and bring trees down, which it did last week in some places.

This also highlights the importance of pruning and keeping trees and shrubs to a manageable size, particularly in a smaller garden setting, to ensure they do not do structural damage if branches break.

Some damage was done to early flowering bulbs and winter bedding in the big freeze, some of which will bounce back in due course.

The polytunnel got a coating of snow also, which was removed by pushing up on the inside as the weight of the snow could split the plastic.

On the surface of the soil, the snow serves as an insulator, so it protects the soil and dormant plants beneath.

Have you noticed how quiet everything seems when it snows? This is because a fresh blanket of snow absorbs sound waves, making everything seem quieter.

The freezing spell has passed for now, but cold weather at this time of the year, when the sun is low in the sky, can provide some valuable insights, particularly if you are considering some sort of protected growing environment like a polytunnel or glasshouse.

There are a number of factors to consider when you’re choosing the best location, and one of the most critical is winter sun and maximizing on this most important factor, from when it rises in the east to setting in the south in winter, and further to the west in summer.

Choosing a location where the sun hits from early in the morning to when it sets in winter will ensure that it benefits the most from solar gain when temperatures are at their lowest.

The recent cold snap will have exacerbated the effects of lack of winter sun, meaning lingering snow and frost, and the same principles apply when siting a glasshouse. We want to locate it in the warmest, most sheltered spot to ensure maximum solar gain when the temperatures are low. It can be tricky though, as sometimes a sheltered spot can be a frost pocket if it does not get the sun in winter.

Living with a garden for a few years before undertaking major investment can be a good idea. It gives a chance for you to get to know the garden, and how it and house work together, routes most frequently taken, sunniest corners, coldest corners, and exposed areas.

Listing factors to consider as a paper exercise is one thing, and watching weather, plants, soil, buildings and nature work together is a whole other thing. The cold spell of late can help to provide more information about where the snow lasts the longest, and to plan the best spot for a snowman!

Plant of the Week

Only the hardiest plants are flowering now, and gorse is one of the best for long flowering time - about nine months of the year. It is an introduced plant, as its latin name suggests, from Europe.

Ulex europaeus is a nitrogen-fixing shrub commonly seen carpeting mountainsides. It has spiny, prickly leaves and deep yellow pea-like edible flowers that smell like coconut.

Commonly found growing in hedgerows also, it was noticeable last week for becoming top heavy with snow and cracking under the weight, and thus getting some pruning during the snow.

It will re-grow from the base and commonly layers along the soil, colonizing quickly when conditions are right. This plant will grow on poor thin soils, can cope well with the wind in coastal locations and prefers good drainage.