Subzero Kale Cover Crop is a cold-hardy annual hybrid that thrives in the challenging seasons when most greens struggle. Reaching 12 to 36 inches tall, this open-pollinated Brassica produces lush green foliage packed with nutrients for humans and livestock alike. Ready to harvest in 50 to 59 days, it's built for spring, fall, and mild winter planting in full sun, making it an exceptional choice for gardeners looking to extend their growing season or establish living mulch that feeds the soil and the table.
Full Sun
Moderate
1-10
36in H x ?in W
—
Moderate
Hover over chart points for details
This hybrid kale earns its name through genuine cold tolerance that allows it to flourish when temperatures drop and conventional greens falter. The luxuriant green leaves are as visually striking as they are nutritious, performing double duty as both a forage crop for wildlife and cattle and a human food source. Its rapid maturity, reaching harvestable size in under 60 days, combined with its upright growth habit, means you can fit it productively into tight garden windows.
Subzero Kale works beautifully as a cover crop, building soil health while providing late-season and early-spring foliage for harvest. Its substantial leaf production makes it valuable as livestock forage and wildlife food during dormant seasons. For home gardeners, the young to mature leaves can be harvested fresh for cooking, juicing, or adding to winter salads when other kale varieties have quit producing.
No timeline data available yet for this variety.
Start seeds indoors 4 to 6 weeks before your intended transplant date, using a seed starting mix kept consistently moist at 65 to 75 degrees Fahrenheit. Once seedlings develop true leaves and reach 2 to 3 inches tall, harden them off gradually over 7 to 10 days by exposing them to outdoor conditions in increasing increments.
Transplant hardened-off seedlings into the garden when soil is workable and nighttime temperatures consistently stay above 40 degrees Fahrenheit for spring planting, or 6 to 8 weeks before the first fall frost for fall crops. Space plants 12 to 18 inches apart in full sun. Water gently after transplanting and keep soil consistently moist during the establishment phase.
Direct sow seeds 1/4 inch deep in prepared garden beds, spacing seeds 6 inches apart for later thinning. Keep soil evenly moist until seedlings emerge in 7 to 14 days. Direct sow in spring once soil is workable or in late summer for fall harvest.
Begin harvesting outer leaves once plants reach 8 to 10 inches tall, typically 50 to 59 days after sowing. Pinch or cut individual leaves from the base of the plant, working from outside toward the center, which encourages continued leaf production. For a full-plant harvest, cut the entire plant at soil level when it reaches full size. Subzero Kale's flavor actually improves after light frosts, so delay harvest until after the first chill if possible for sweeter, more tender leaves. Morning harvest, after dew dries, yields the crispest leaves.
Enter your ZIP code to see a personalized growing calendar for this plant.