Kale, a nutrient-dense leafy green, is not just a summer favorite—it thrives in cold weather, even improving in flavor after a light frost! Unlike many delicate vegetables that wilt at the first sign of winter, kale’s hardy nature makes it an ideal choice for gardeners looking to keep their plots productive through the colder months. Whether you’re a seasoned gardener or a beginner, this guide will walk you through everything you need to know to grow lush, healthy kale this winter.
1. Choose the Right Winter-Hardy Kale Varieties
Not all kale varieties are created equal when it comes to cold tolerance. For winter growing, opt for hardy varieties that can withstand temperatures as low as -15°C (5°F) with proper protection. Some top picks include:
-
Lacinato Kale (Dinosaur Kale): With long, wrinkled leaves, this variety is extremely cold-hardy and develops a sweeter taste after frost.
-
Red Russian Kale: Features frilly, purple-tinged leaves and is one of the most cold-tolerant kale types, perfect for northern climates.
-
Curly Kale: The classic kale with ruffled leaves; look for cold-hardy cultivars like ‘Winterbor’ or ‘Vates’ which are bred specifically for winter growing.
Avoid tender varieties like ‘Redbor’ if you live in an area with harsh, prolonged winters—stick to the tried-and-true cold-resistant types for the best results.
2. Start Seeds Indoors (Timing Is Key)
To give your kale a head start before the cold sets in, start seeds indoors 6-8 weeks before your area’s first expected frost date. This timing ensures the plants are well-established (about 4-6 inches tall with 4-6 true leaves) when it’s time to transplant them outdoors.
Here’s how to start your kale seedlings:
-
Fill seedling trays or small pots with a well-draining seed starting mix. Moisten the mix thoroughly before sowing.
-
Sow 2-3 seeds per cell, placing them ¼ inch deep. Cover lightly with soil.
-
Place the trays in a warm, well-lit spot—aim for a temperature of 15-20°C (59-68°F). A sunny windowsill or grow light works perfectly (as shown in the illustration above).
-
Keep the soil consistently moist but not waterlogged. Seeds should germinate in 5-8 days.
-
Once seedlings have their first true leaves, thin them out, leaving only the strongest seedling per cell.
3. Transplant Outdoors: Prepare the Soil and Site
When the seedlings are 4-6 weeks old and nighttime temperatures stay above 10°C (50°F), it’s time to transplant them outdoors. Choose a sunny spot—kale needs at least 6 hours of direct sunlight daily, even in winter. If sunlight is limited, aim for 4 hours of bright, indirect light.
Soil preparation is crucial for winter kale success: Kale prefers well-draining, fertile soil with a pH between 6.0 and 7.5. Test your soil and amend it with compost or well-rotted manure to boost nutrients and improve drainage.Before transplanting, add a layer of organic mulch (like straw, leaves, or pine needles) to the soil surface. This helps insulate the roots, retain moisture, and suppress weeds—all essential for winter growth.When transplanting, space the seedlings 18-24 inches apart (45-60 cm) to give them room to grow. Dig a hole slightly larger than the root ball, place the seedling in the hole, and firm the soil around it. Water thoroughly after transplanting to help the roots establish.
4. Winter Care: Protect and Nourish Your Kale
Once temperatures drop below 10°C (50°F), your kale will slow down growth but continue to thrive. Here’s how to care for it during winter:
-
Watering: Water sparingly—only when the top 1-2 inches of soil are dry. Avoid overwatering, as cold, wet soil can lead to root rot.
-
Protection from Extreme Cold: For temperatures below -10°C (14°F), use row covers, cloches, or cold frames to insulate the plants. Remove covers during the day when temperatures rise above freezing to allow air circulation.
-
Fertilizing: Avoid fertilizing after the first frost, as this can stimulate new growth that’s vulnerable to cold damage. Instead, apply a slow-release organic fertilizer at transplant time to nourish the plants through winter.
5. Harvesting Winter Kale: Enjoy the Sweet Flavor
The best part about winter kale? Frost converts the starches in the leaves to sugars, making them sweeter and more tender than summer-grown kale! You can start harvesting leaves once the plants are 8-10 inches tall, usually 4-6 weeks after transplanting.
Harvesting tips: Use sharp scissors or pruning shears to cut outer leaves first, leaving the inner leaves to continue growing. This way, you can harvest from the same plant multiple times throughout winter.Harvest in the morning when the leaves are crisp and full of moisture.Avoid harvesting more than ⅓ of the plant at once—this ensures the plant stays healthy and continues to produce new leaves.Kale can be harvested until the plants are covered in heavy snow or temperatures stay below -15°C (5°F) for an extended period. Even if the leaves look a bit wilted after a cold snap, they’ll perk up once brought indoors!
Troubleshooting Common Winter Kale Problems
While kale is hardy, it can face a few issues in winter: Pests: Aphids and cabbage worms may still be active in mild winters. Use insecticidal soap or introduce beneficial insects like ladybugs to control pests. Row covers can also help keep pests away.Root Rot: Caused by cold, wet soil. Ensure proper drainage and avoid overwatering to prevent this.Leaf Damage from Frost: Light frost damage (brown edges) is harmless and won’t affect the taste. Severe damage (black, mushy leaves) means it’s time to harvest the remaining healthy leaves.Final Thoughts: Embrace Winter Gardening with KaleGrowing kale in winter is a rewarding experience that lets you enjoy fresh, nutrient-packed greens even when most gardens are dormant. With the right variety selection, proper timing, and a little protection from extreme cold, you’ll have a steady supply of sweet, tender kale from late fall through winter.
So grab your seeds, prepare your soil, and get ready to grow your own winter kale—your taste buds (and your body) will thank you!
