Winter gardening (Credit: Marcus Harpur/Flora Press).

Why we should welcome the colder weather

Many of us have bemoaned the lack of cold, frosty mornings this winter. Few gardens look more spectacular than when decorated with a hoar frost. However, as a cold front is upon us this weekend, our prayers might be answered.

The large, needle-like crystals of a hoar frost cling to sedum heads, eryngiums and other plants with strong silhouettes, making you glad that you had not tidied up too soon.

But with the rain and wind that has battered our gardens over the past couple of months, most herbaceous plants look more mushy than magnificent – and the dull light at this time of year renders them even less appealing. Herbaceous plants have become increasingly popular, but in a wet, warm winter they have a long off-season.

I’m thankful that in my main courtyard garden, overlooked by much of the house and offices, herbaceous plants are used within a structure of low hedges, topiary, small trees and evergreens (mainly phillyrea, bay, yew, box) with tall obelisks adding extra punctuation. In certain climates, such as northern Japan, the off-season is barely noticeable and big expanses of herbaceous plants work brilliantly.

There, the gardens are covered in snow for months, spring comes rapidly, and it is often only a few weeks before the snow melts and new herbaceous growth blasts out of the ground as if jet-propelled.

Having decided I was going to write about lack of frost, I woke up and realised that, here in Cambridgeshire at least, we have had one light ground frost. A clear sky and conditions just below freezing had turned the dew into tiny icy crystals that made the lawn sparkle in the early morning sun.

Air temperatures are measured at 1.25m above the ground, but on still, calm nights if you measure the temperature on the ground it can often be 3C-4C lower. In colder autumns (when the ground is still warm) we’ve had air frosts, when the heat radiating from the ground prevents the lower levels freezing although air above the ground freezes.

As the soil is holding so much moisture now and is still quite warm (my celeriac and fennel are still growing) the ground loses less heat, and that also helps to reduce the chance of frost. Going out to shut the greenhouses the other evening, I was accompanied by unseasonable birdsong and the bees were busy foraging. There are numerous reports of primroses and daffodils doing their stuff much earlier than usual. Pests, notably slugs and snails, are also capitalising on the warmth and wet.

Pest profusion Pest and disease expert Pippa Greenwood says slugs are a big problem, especially as there is young edible growth on many plants. While out picking spinach in the dark the other week with my head torch on high beam, I was astonished at the amount of tiny slugs and the occasional young snails caught in the light. I quickly added a mulch of Strulch (mineralised straw,, and my young kale and cabbages, too. Pippa says aphids have already been spotted on roses in gardens, which seems incredibly early.

Fuzzy grey mould (Botrytis cinerea) attacks overwintering plants in greenhouses, and in these warm, wet conditions it has zoomed in on my cuttings of perennial wallflowers. Pippa recommends popping young plants into a poly bag as you remove the infected leaves to prevent the mass of disturbed spores settling on pastures new.

The warm and wet has caused outbreaks of box blight on a large scale, even in my normally dry, free-draining soil. Brown patches are popping up randomly and spreading. I had the odd patch last year; by using two alternating fungicides, Signum and Octave, then applying organic SB Plant Invigorator (the latter breaks the fungal cells’ surface walls,, thankfully all patches disappeared and the foliage came back good as new.

These fungicides are for commercial use and can only be applied by people with spray qualifications PA1 and PA6a. Either do the course (approx 2½ days, £350) or pay a qualified person to spray for you. The ferocity and speed of blight’s comeback this winter, combined with the fact that the box plants are still growing, pushed me into spraying in December and early January, which should sort it.

Foraging bees

Speaking to Jane Moseley of the British Beekeepers Association (, I became even more concerned about our bees. The warm weather has meant they are still active and foraging, feeding on plants such as viburnums and cherries. The pollen they take to the hives apparently stimulates the queen bee to lay eggs which pushes up the hive population unseasonably early.

If it later turns cold it is likely they will starve. Jane suggests I feed my bees with fondant and plant more nectar-rich plants (annuals, shrubs and trees) to give them a wide palette to forage on – see Quite a few plants need some winter chilling. February is often one of the colder months and a freeze can be necessary to help daffodils, some tulips and hyacinths. Apples, cherries, pears, blackcurrants and plums also require a period of cold which breaks down the growth inhibitors. If they don’t get this you can see sporadic or delayed leaf and flower formation.

BBC weatherman Peter Gibbs reassures me, though: “The record mild start to winter which has been confusing our garden plants was likely a knock-on effect of the very strong El Niño phenomenon in the Pacific. The Met Office forecast reckons the second half of the winter is often colder in a strong El Niño year so we should expect a lot more frost and occasionally snow.”