Winter is fast approaching, and this can be a challenging season for gardeners. Many homeowners will neglect their outdoor spaces during this time, but for gardeners, it is important to know how you can protect your crops during the colder months of the year.

Keep reading to learn how the winter affects your crops and what steps you can take to overcome these challenges.

polytunnel with vegetables

A polytunnel can protect your vegetables all year round

Frost Damage

One of the biggest threats during the winter months is frost damage. When the temperature plummets and frost begins to develop, it can cause damage to plant tissues that can result in wilting, browning, or even the death of leaves and stems.

Frost can penetrate the soil and damage the roots of some plants, which affects their ability to absorb water and nutrients. Polytunnels are an effective solution that can protect your crops from frost damage.

Solutions

  • Mulching: Insulate the soil by applying a thick layer of organic mulch (such as straw or compost) around the base of plants to keep roots protected from frost.
  • Row Covers: Use frost cloths or fleece to cover crops, trapping warmth and moisture. Remember to remove them during the day for proper ventilation.
  • Frost-Tolerant Crops: Focus on hardy vegetables like kale, Brussels sprouts, and parsnips, which not only survive but often improve in flavour after frost exposure.

Reduced Growth Rates

The cooler temperatures of winter can slow down plant metabolism and growth. This is particularly true for warm-season crops, which require higher soil and air temperature to thrive. Many perennial plants enter a period of dormancy during winter to conserve energy, pausing their growth until spring. While some plants go dormant in the winter months, there are also many that thrive in harsher conditions that you might want to focus on.

Solutions

  • Grow Frost-Hardy Crops: Plant winter vegetables like root vegetables and leafy greens that thrive in cold conditions. See below for suggestions.
  • Maximise Light Exposure: Position plants in the sunniest parts of your garden, such as south-facing spots, or supplement natural light with full-spectrum LED grow lights.

Shorter Daylight Hours

Of course, the shorter daylight hours during this time of the year deprive plants of the energy needed for photosynthesis. This can slow growth, reduce yields, and cause some plants to stop growing altogether. This is why gardeners need to know which areas of their space get the most sunlight or use indoor grow lights as an alternative.

Solutions

  • Use Indoor Grow Lights: Full-spectrum LED grow lights can extend the growing season, especially for leafy greens such as lettuce and spinach.
  • Optimise Sunlight: Plant in areas that receive maximum daylight or place indoor plants near south-facing windows to ensure they get as much natural light as possible.
leeks grown in protective plastic

You can protect the roots from frost with DIY hacks too

Water Stress

Soil in London tends to be either chalky or clay based which retains water well. Ideal for summer, not so good in periods of heavy rain where it can get waterlogged. This means that the winter rainy periods can be a concern as they can lead to suffocated roots, rot, and fungal diseases.

And of course, if the ground freezes, water becomes unavailable to plant roots, which can cause dehydration and wilting in cold weather.

To test drainage, simply dig a foot deep hole and fill with water. Once it’s fully drained, repeat to simulate heavy rain and time how long it takes to drain completely. Ideally, the water should drain at a rate of 1 to 2 inches per hour which is considered good drainage.

Solutions

  • Improve Drainage: Use raised beds or sloped garden beds to ensure water drains away from crops efficiently. Adding drainage channels or improving soil structure with well-draining materials can help.
    For Poor Drainage: Improve by adding organic matter such as compost, which can help break up heavy clay soils.
  • Rainwater Harvesting: Collect rainwater using barrels to ensure a steady water supply during dry spells, minimising waste and protecting against waterlogged soil.

Pests & Diseases

There are a few fungal and bacterial diseases to be aware of in winter, including root rot, downy mildew, and blight. Some plants are stressed by the cold weather, which can make them more vulnerable to infection. There are also various pests that thrive in damp conditions, including slugs and snails, which can damage crops such as cabbages, kale, and spinach.

Solutions

  • Biodegradable Frost Covers: Use eco-friendly frost covers made from biodegradable materials to protect crops without adding to plastic waste.
  • Natural Pest Control: Encourage beneficial insects that prey on pests or use barriers like copper tape around plant beds to deter slugs and snails.

These are the main ways that winter affects your crops. With shorter days, colder temperatures, rain, and diseases and pests, winter is a challenging season, even for a seasoned gardener. It is important to be aware of what the main challenges are at this time of the year so that you can prepare and take action to ensure that you are able to protect your crops.

Curly Kale in winter

Curly Kale is easy to grow in the British winter

Crops that thrive in the UK winter

Brassicas

    1. Brussels Sprouts are best planted in spring for an autumn and winter harvest, they often taste sweeter after frost exposure.
    2. Winter Cabbages including hardy varieties like the Savoy cabbage, do well and are great for winter dishes.
    3. Purple Sprouting Broccoli is sown in spring, this crop overwinters and provides early spring harvests.

Root Vegetables

  • Carrots are cold-hardy and can be harvested throughout winter. They thrive in well-draining soil and benefit from a layer of mulch for frost protection​.
  • Beetroot is frost-tolerant and can be sown late into summer for a winter harvest. They are ideal for winter soups and salads.
  • Parsnips are excellent for winter growing as their sweetness improves after frost. They are cold-resistant and provide both edible roots and leaves. They can be harvested throughout the winter.
  • Turnips can be harvested as needed and are great for winter stews and soups.

Leafy Greens

  • Mustard Greens are resilient in cold weather and provide a spicy addition to winter salads. They can be harvested in late autumn and early winter.
  • Kale is one of the most hardy greens, known to withstand frost and improve in flavour after exposure to cold temperatures.
  • Swiss Chard can tole​rate freezing temperatures and continues to produce leaves throughout winter. It requires minimal protection and grows well in most UK climates.
  • Winter Spinach varieties can be harvested during the cold months for fresh salads.

Extra Resources

RHS: Overwintering tender plants: lifting or mulching
RHS: Winter vegetables