What to Do When It Snows in Your Scottish Garden

Wet snow is settling on the hoops over the salad bed, the conifer by the gate is bowing towards the path, and the hedge has a white cap that gets thicker every time you look. The veg bed under its blanket looks fine, even peaceful. The question is whether to go out and shake, brush or sweep, or to leave the whole lot alone and let it melt.

At a glance

The same snow does two jobs

A layer of snow lying on soil and low plants is a blanket. Snow lying on a branch, a hoop or a roof is a load. The useful question at the window is whether the snow is resting on the ground or hanging off something.

Snow forms when the air is below about 2°C, and the heaviest UK falls tend to come between 0 and 2°C, not in deep cold. Near freezing, flakes melt slightly at the edges and stick together into big, heavy clumps that cling to whatever they land on. Colder, drier air gives small powdery flakes that don't bind together and tend to blow off or drift.

So the same 5cm can mean two very different mornings. Powder mostly slides off in the first breeze; wet snow bonds to every twig. Temperature at the moment of the fall matters more than the depth reported.

Heavy snow near the coast, longer-lying snow inland

Scotland gets both types, and where you garden shifts the odds. On the mild Atlantic side, snow that does fall is often the near-freezing, heavy kind that clings to branches and hoops. In the east and the Highlands, colder air more often gives drier snow that lies, drifts and stays for days, and on an exposed plot wind piles that drift against hedges, tunnels and fences. Expect a heavier load on the west coast and a longer-lying one inland, as a tendency rather than a rule.

How often snow lies varies a lot. A lying-snow day means more than half the ground is covered at 9am. The figures come from different averaging periods, so compare rows loosely.

These are long-term averages and single winters differ hugely. On many lowland and coastal plots a lying-snow spell is an occasional event, so the job is being ready for one. Higher ground has far more, with more than 50 lying days over the higher ground of Northern Scotland (the fencing and windbreak comparison has the wider picture, and Scotland frost dates the frost side). Rare heavy falls still happen at low level: a cold westerly in January 1984 left 20 to 30cm of undrifted snow in Argyll, and in December 2010 Livingston Mill west of Edinburgh reached 60cm.

Hedges, conifers and shrubs

Snow that sits on hedges or the crownsThe base of a perennial plant where roots and shoots meet, often sold and planted as a ready-made dormant plant rather than grown from seed. Full definition → of trees can break branches. Shake off excess snow as it starts to build up, and prune hedges so they taper at the top and shed snow rather than hold it. Conifers, climbers and light-limbed shrubs and trees are the ones that most need brushing, because heavy snow can splay branches, break limbs and spoil the shape of the tree.

• Start early. A branch bowed by a light coating usually springs back; one carrying a night's wet snow with a hard frost on top is close to snapping.
• Work from underneath, upwards. Lift the branch tips with the flat of a broom head or a gloved hand and let the snow slide. On smaller conifers and shrubs a gentle shake of the main stem finishes the job while the snow is still soft; once it is frozen on or iced over, don't shake at all.
• Don't beat or whack. Frozen wood and evergreen foliage are stiff and brittle, and a sharp blow can crack a limb that would have sprung back on its own. If a branch is coated in ice, not just snow, leave it until it softens; the ice is not something you can shift without damage.
• Don't climb for it. A hedge top you can't reach from the ground isn't worth a fall on an icy path.

A flat-topped hedge is the easiest to overload, so cut a tapered top in at the next trim. If a splayed conifer doesn't recover, see conifer hedge browning; clipped shapes are in topiary basics. Before a forecast heavy fall, loosely tying in the stems of a multi-stemmed conifer or shrub with soft twine helps it carry the load, and it is easier than clearing afterwards.

Polytunnels, greenhouses, cold frames and cloches

Snow should come off greenhouse and conservatory roofs, both to prevent damage and to let light in. A polytunnel is different, because the cover flexes and the hoops carry the weight. The wind-and-snow combined load is covered in securing a greenhouse or polytunnel against wind.

Clearing one safely:

• From inside, push up. Stand inside and use the padded head of a soft broom to lift the cover gently along the roof, working from the ridge outward so the snow slides off. Pushing from the inside avoids leaning on the structure.
• Clear both sides evenly. If you sweep one side only, you leave a lopsided load on the hoops.
• Nothing sharp, and no ladders on a slippery cover. A rake or spade will cut polythene.
• Don't leave clearing until the snow has frozen hard. It is far easier while it is still loose. Once it has been through a thaw and refrozen it stays put.

Cold frames need less: clear the lid on the first bright morning so light gets in. Cloches and low hoops over salads are the ones that collapse, so knock snow off before it bows the wire and straighten any that bent once it has gone. On a western plot where the snow arrives wet, this is the first job; on an eastern or upland one, expect to repeat it as drifts build. More on cold frames and winter salads under cover, and on whether a tunnel or greenhouse suits a snowy site, in polytunnel vs greenhouse and are polytunnels worth it.

No single depth is safe for every tunnel. Frame, hoop spacing and cover age all matter, and the maker's rating is the figure to trust. Heat retention is covered in insulating a greenhouse for winter.

Crops under snow

Hardy crops in the ground don't need rescuing. Broccoli, Brussels sprouts, cabbages, kale, leeks and parsnips stand through winter, and the snow around them does no harm; which ones earn a place is covered in top 5 crops for winter harvest. To harvest, brush snow back from just the plants you want and put it back afterwards.

What needs clearing is anything holding snow up: bird or insect netting, fruit cages, and fleeceA lightweight, breathable fabric laid or draped over plants to trap a little warmth and keep off frost, wind and some flying pests. Full definition → or hoops over the crop. Treat those like any hoop, and if a fruit cage's netting is still on for winter, take it off or lift it clear so it can't sag under the weight. Fleece does nothing against snow load; for cold snaps without snow, see fleece grades and timing and protecting plants from frost.

Lawns

Snow-covered grass is fine. Walking on it or on a frosty lawn is not: frosted grass blades go brittle, and footprints can leave brown marks that take several weeks to fade. Stay off until the lawn has thawed and dried, and if you have to cross it every day, lay stepping stones so you are not wearing a path into it.

Yellow or brown patches after snow can be the fungal disease fusarium patch (snow mould), which favours wet weather and overfed, lush lawns left a bit long between mowings. That fits a wet western lawn especially. Prevention is a matter of not feeding late, mowing before winter and getting water off the surface: see waterlogged lawn on clay soil and moss in your lawn.

Pots and containers

Pots are the plants most exposed to a cold spell, because roots have nothing around them but a thin wall. For a snowfall: group pots together in a dry, sheltered spot, wrap the pots in bubble polythene or straw to keep the roots from freezing, or plunge them into the ground with the rim just showing. Leave snow banked around the base. What you do want to avoid is a pot filling with meltwater and refreezing solid. Lift pots onto feet so they can drain, or tip small ones on their side under cover. Potted fruit trees get their own treatment in winter protection for potted fruit trees.

Fruit trees and wall-trained plants

Fruit trees can be brushed like any other tree. The bigger question is a branch that has already torn. Prune out torn or damaged branches to prevent disease getting in, cutting back into undamaged wood, ideally to a natural fork so you don't leave stubs.

Plums and other stone fruit such as cherries are the awkward ones. Winter pruning raises the risk of silver leaf, a fungal disease that gets in through cuts, and the best time to prune plums is spring for young trees and mid-summer for established ones. If a stone fruit has a limb hanging by a strip of bark, make it safe now and leave the proper tidy-up cut until the pruning window, unless the limb is a hazard.

Wall-trained fruit and climbers take the strain on their wires and ties, especially where a slab can slide from a roof edge above them. Brush climbers as you would a light-limbed shrub, and re-tie anything that has pulled loose afterwards.

The thaw

Most of the trouble comes after the snow. A fast thaw, especially if rain arrives with it, sends a lot of water into soil that may still be frozen underneath, so it runs off or pools rather than draining. Snowmelt can contribute to winter and early-spring flooding in Scotland: in January 1993, thawing snow plus heavy rain flooded the Tay valley. Hollows and low beds hold water, so clear drains and gullies of leaf litter before the melt and don't dig or tread wet soil (see sodden garden after heavy rain and flooded plot drainage).

Once the snow has gone, walk the garden and check:

1. Structures first. Look for bent hoops, loose polythene, cracked glazing and slipped ties. Repair before the next wind.
2. Torn branches and leaders. Assess and prune as above.
3. Crops. Lift a few brassicaThe cabbage family: cabbage, kale, broccoli, cauliflower, Brussels sprouts, kohlrabi, swede, turnip and more, sharing the same pests, diseases and rotation rules. Full definition → leaves to look for collapsed or slimy growth, and remove it.
4. Standing water and heaved plants. Firm back any recently planted shrub that frost has lifted.
5. Slug activity. Slugs can be out hunting on mild damp evenings, and a thaw is exactly that. If you have salads or young plants uncovered, check them after dark; slug deterrents that actually work covers the options.

Birds and other wildlife need help in a hard spell too: see helping garden wildlife through snow and freezing weather.

De-icing: salt, grit and what to use near beds

Rock salt is sodium chloride, and it can damage trees and shrubs through contaminated soil or as spray. Via the soil, chloride from the salt is taken up by roots and builds up in dormant twigs and buds; the first sign the following spring is often buds that fail to open, or leaves that open and then wither, sometimes leaving bare branches. Severe damage can kill young and newly planted trees.

Trees and shrubs beside a salted path are exposed to splash, runoff and shovelled snow that can carry a lot of salt, and hand-spreading is one of the main ways a garden ends up over-salted, because it is easy to apply a lot. Beside roads, damage is worst close in and falls off with distance, plants downhill of the salted surface suffer more than those uphill, and plants in a hollow suffer more than those on a raised bed. The same pattern is likely beside a salted path. Roots that reach drains carrying salty runoff can be hurt further away.

In practice:

• Don't shovel salty snow onto beds. Pile it on a hard surface or where nothing grows and where the meltwater can't pool around roots.
• Keep salt to the surface you need it on. Use as little as will do, sweep excess back onto the path, and keep a strip at the edge of any bed salt-free.
• Don't use bagged road grit or rock salt near new plantings. Newly planted trees are the most vulnerable.
• Clear first, then treat. Shovel or brush snow off a path while it is fresh, then use only a light dressing where you need grip.
• Use a non-salt option where you can. Urea and calcium magnesium acetate (CMA) are the recognised alternatives in sensitive areas. Sand or fine grit adds traction without adding chloride, though it is only traction, not melting, and it will end up in your borders and drains, so sweep it up in spring.

Keep salt off the lawn edge where it meets a path too. Clear the route you actually walk (steps, gate, path to the shed) and leave the rest, since a shovelled strip needs far less salt than a whole drive. Salt on paving and decking is covered in garden path materials for a wet climate, and soil that has picked up salt from winter road grit is in gypsum vs clay soil fixes.

Common questions

Sources