February might seem early to start growing, but collard greens, sometimes referred to as "spring greens" or "tree cabbage" in the UK are a hardy crop that can handle cooler temperatures. While true spring greens in the UK are typically young cabbages, collard greens are a distinct variety of leafy green vegetable, known for their large, dark green leaves and slightly bitter flavour. Both are excellent cool-weather crops, but collard greens are particularly robust and frost-tolerant.
Collard greens are a crop you can plant as early as February, and you'll be rewarded with fresh, nutritious greens when other crops haven’t got started.
When to Plant Collard Greens
Collard greens can be grown throughout the year, but February is an especially good time to start sowing seeds indoors with a view to moving the seedlings outdoors in early spring. They thrive in cooler weather and can even tolerate light frosts, which can improve their flavour.
How to Sow Collard Greens
Sow seeds thinly, about 1 cm deep, in trays of moist compost. The seeds typically take around 5-10 days to germinate. Once they start to get crowded, thin them by about half to leave the stronger seedlings. By the time they are ready to transplant, the outdoor conditions will be improving.
Collard greens love cooler weather, but they need protection from harsh frosts when they are young, so indoor sowing is ideal. If your windowsills are overcrowded, consider using a Light-Booster Plant House or Cold Frame to house your seedlings. These growing spaces will maximise the low light early in the season and boost your seedlings' growth.
Alternatively, if you have a greenhouse, polytunnel, or Easy Poly Tunnel, you can sow the seeds directly in February for an early crop. Top tip: if you do have an Easy Tunnel, place it over your vegetable bed a few weeks before you intend to sow to warm the soil prior to planting.
Where to Plant Collard Greens
When it comes time to plant your collard greens seedlings outdoors, choose a sunny spot in your garden with well-drained soil. Collards thrive in slightly acidic soil (around pH 6.0 to 6.8) and appreciate soil that has been enriched with compost or well-rotted manure.
In February, the ground might still be cold, so raised beds are an excellent choice. Raised beds warm up faster than the ground, providing a better growing environment for early crops. Or, as mentioned above, use an Easy Poly Tunnel to pre-warm the soil prior to planting.
How to Transplant Collard Greens
Check your expected last frost date, and if a late frost is a concern, make sure to harden off your seedlings by gradually exposing them to outdoor conditions over a week before fully planting them outside.
Collard greens sown indoors in February can usually be transplanted outdoors by late March or early April. Space them about 18-24 inches apart to allow enough room for their large leaves to spread. If you’re sowing directly outdoors, plant the seeds about ½ inch deep and 6 inches apart. Once they germinate and grow a bit, thin them to the correct spacing.
Recommended Tool: Haxnicks Easy Fleece Tunnel
To protect your newly transplanted collard greens from unpredictable late frosts or cold winds, use the Easy Poly Tunnel you used to warm the soil or an Easy Fleece Tunnel. This will create a mini greenhouse effect, keeping your plants warm while still allowing air to circulate.
How to Care for Collard Greens
Once your collard greens are in the ground, they’re relatively low-maintenance. Keep the soil consistently moist, but not waterlogged, as the plants dislike dry conditions. Water them regularly, especially during dry spells, and mulch around the base of the plants to retain moisture and suppress weeds.
As they grow, feed them every 4-6 weeks with a balanced organic fertiliser. Collard greens are heavy feeders, meaning they benefit from nutrient-rich soil throughout the growing season.
Keep an eye out for common pests such as cabbage worms, aphids, and slugs. Check the undersides of leaves regularly, and if you see pests, remove them by hand or use a safe organic pesticide. Netting can also help keep larger pests, such as pigeons, from damaging your plants.
The Haxnicks Easy Net Tunnel is great for protecting your greens from pests like pigeons and caterpillars, which can easily ruin a crop if left unchecked.
Harvesting Collard Greens
You can start harvesting collard greens about 60-85 days after planting. The leaves are ready to be picked when they’re about 10-12 inches long. Start by harvesting the outer leaves, allowing the inner leaves to continue growing for future harvests. This way, you can enjoy a continuous supply of collard greens over several months.
Fun Fact: Did you know that collard greens become sweeter after being exposed to a light frost? The cold weather causes the plant to convert some of its starches into sugars, giving the leaves a milder and sweeter taste!
Year-Round Care for Collard Greens
Collard greens can be grown almost year-round with the right planning. After your February planting, you can continue sowing seeds throughout the spring and even into early summer for a continuous harvest. For an autumn or winter crop, plant seeds outdoors in July or August. Collard greens are hardy enough to keep producing well into winter, and with some frost protection, they can survive through the colder months.
Collard Greens Storage and Cooking Tips
After harvesting, collard greens will keep in the fridge for up to a week. For longer storage, they can also be blanched and frozen.
These nutrient-packed greens are versatile in the kitchen. You can sauté them, add them to soups, or even steam them. A traditional Southern USA dish involves slow-cooking collards with garlic, onion, and a bit of vinegar for a hearty, warming meal.
Happy Gardening!
Whether you call them collard greens or spring greens, these hardy, nutritious plants are a fantastic addition to any garden. With a little care and attention, you’ll be enjoying fresh, homegrown greens throughout the year.
Comments
Hi Patricia, thanks for pointing that out. Collard greens are also known as Spring greens in the UK but you are indeed right -they are separate members of the brassica family and I have re-written the first paragraph to make this clearer. I’m not sure it is enough to stop people calling them Spring Greens though! All the best.
Spring greens are from small loose undeveloped cabbage, not collards. Collards are a different plant entirely. Collards are tough, not tender like spring greens.