How to Grow Kale for a Winter Harvest: A Step-by-Step UK Gardening Guide

Introduction

Looking for a leafy green that thrives when everything else in the garden has slowed down? Kale is the answer. This hardy, nutrient-packed vegetable loves cool weather and can withstand frosts and even snow, making it a perfect crop for the winter garden. Whether you’re new to gardening or a seasoned grower, learning how to grow kale for a winter harvest ensures fresh, healthy greens from your plot when little else is growing.

In this comprehensive step-by-step guide, we’ll walk you through everything you need to know—from choosing the best kale varieties to sowing, caring, protecting from pests, and harvesting during the colder months.

Why Grow Kale in Winter?

❄️ Frost-hardy: Kale actually tastes sweeter after a frost
🥗 Nutritious: Packed with vitamins A, C, K, and iron
🌱 Low maintenance: Grows well with minimal effort
🌿 Productive: Keeps producing leaves over many months
🪴 Perfect for UK winters: Can be grown in beds, raised beds, and containers

Best Kale Varieties for Winter Harvesting

Variety	Type	Notes
Winterbor F1	Curly Kale	Very hardy, frilly leaves, high yield
Nero di Toscana	Cavolo Nero	Also called Tuscan kale; tall, elegant leaves
Redbor F1	Red Curly Kale	Striking purple leaves, excellent cold tolerance
Dwarf Green Curled	Curly Kale	Compact, great for exposed or windy plots
Hungry Gap	Spring/Winter Kale	Produces leaves when others are dormant

Top Tip: For winter cropping, choose varieties specifically described as “cold-hardy” or “overwintering.”

When to Plant Kale for a Winter Harvest (UK)

Task	Best Time
Sow indoors	May to June
Sow outdoors (seedbed)	Late May to July
Transplant to final position	June to August
Harvest leaves	October to March

Kale is a cool-season crop, and late spring/early summer sowings give plants time to grow before winter.

Where to Grow Kale

Kale is a versatile vegetable that grows well in:

Traditional vegetable beds
Raised beds
Large containers or grow bags (min. 30cm deep)
Polytunnels or cold frames (for very cold areas)

Ideal Growing Conditions:

Full sun to partial shade
Firm, fertile, well-drained soil
Neutral pH (6.5–7.5)

How to Grow Kale for Winter: Step-by-Step

Step 1: Prepare the Soil

Kale prefers:

Rich soil with plenty of organic matter
Well-rotted compost or manure added a few weeks before planting
A balanced fertiliser raked in before sowing or transplanting

Tip: Kale is part of the brassica family, so follow crop rotation rules to avoid soil-borne diseases.

Step 2: Sow the Seeds

Option 1: Indoor Sowing (May–June)

Sow seeds in modules or seed trays
Sow 1cm deep and keep at 15–20°C
Water lightly and keep in a bright location
Harden off and transplant when 8–10cm tall

Option 2: Outdoor Sowing (Late May–July)

Prepare a seedbed with fine tilth
Sow seeds in rows 1cm deep, 30cm apart
Thin to 5cm apart once seedlings emerge
Transplant to final position when plants are 10–15cm tall

Step 3: Transplant to Final Growing Site

Transplant when plants are 4–6 weeks old
Space 40–60cm apart in rows 50–60cm apart
Water well before and after planting
Firm the soil around each plant to prevent root rock

Caring for Kale

1. Watering

Water consistently during dry spells
Avoid waterlogging—especially in winter
Water early in the day in cooler months

2. Feeding

Apply a general-purpose feed once every 4–6 weeks
For a boost, apply liquid seaweed or comfrey tea mid-season

3. Mulching

Add a layer of mulch (straw, compost, leaf mould) around the base
Retains moisture and protects roots from temperature swings

Protecting Kale from Pests

Even in winter, pests can be an issue.

Pest	Symptoms	Prevention & Control
Cabbage white butterfly	Caterpillars, holes in leaves	Cover with insect mesh in summer
Cabbage root fly	Wilting, stunted plants	Use brassica collars around stems
Aphids	Sticky residue, curled leaves	Spray with water or use insecticidal soap
Slugs and snails	Ragged holes in young leaves	Use traps, pellets, or copper tape
Pigeons	Stripped leaves, damaged plants	Net plants, especially in autumn and winter

Harvesting Kale in Winter

When to Harvest:

Begin harvesting from October through March
Pick young outer leaves first, leaving the centre intact
Avoid picking all the leaves at once—this allows continuous growth

How to Harvest:

Use clean scissors or gently twist leaves off by hand
Regular picking encourages new leaf growth
Remove yellowing or damaged leaves to keep plants healthy

Bonus: Some varieties, like Cavolo Nero, will keep producing leaves into early spring!

Storing and Using Kale

Short-Term Storage:

Store fresh kale in the fridge in a perforated bag
Keeps well for up to a week

Freezing Kale:

Blanch leaves in boiling water for 2–3 minutes
Cool in ice water
Drain and freeze in bags or containers

Culinary Uses:

Steamed or sautéed as a side
Added to soups, stews, and curries
Baked into crispy kale chips
Mixed raw into salads and smoothies (young leaves only)

Growing Kale in Containers

Kale is ideal for container gardening.

Container Growing Tips:

Choose a 30–40cm deep container
Use multipurpose compost mixed with loam
Sow directly or transplant seedlings
Water regularly and feed monthly
Protect from pigeons with netting

Best Container Varieties: Dwarf Green Curled, Red Russian, or Baby Leaf types

Cold Weather Protection for Kale

While kale is frost-hardy, protection helps extend the harvest.

Protection Methods:

Fleece or cloches in extreme cold
Polytunnels or cold frames for tender varieties
Mulch around roots to insulate soil

Tip: A light frost improves kale’s flavour—don’t rush to harvest after the first chill!

Succession Sowing for Winter Kale

To ensure continuous winter cropping:

Sow in May/June for autumn harvests
Sow again in July for peak winter cropping
Sow hardy varieties like Winterbor or Redbor for late winter into early spring

Companion Planting with Kale

Good Companions:

Leeks – different root zones and disease resistance
Onions and garlic – deter aphids and caterpillars
Beets – similar growing conditions but don’t compete
Calendula and nasturtiums – attract beneficial insects

Avoid Planting With:

Other brassicas – may share pests or deplete soil
Tomatoes or beans – prefer different conditions

Crop Rotation and Aftercare

Rotate kale and other brassicas every 3 years
Follow kale with legumes like beans or peas to restore nitrogen
After final harvest, remove old plants and compost them (if disease-free)

Conclusion

Kale is one of the easiest and most rewarding vegetables to grow for a winter harvest. With its ability to withstand cold weather and keep producing throughout the darkest months, it offers a steady supply of fresh, healthy greens when most crops have faded.

Whether you’re growing in garden beds, raised beds, or containers, following this step-by-step guide ensures a bountiful winter kale harvest that will keep your kitchen stocked and your garden green even in the bleakest months.