Kale is one of the most cold-hardy vegetables you can grow, and knowing that changes how you approach it. Unlike most garden crops that need frost-free conditions, kale actually improves with cold — a light frost converts some of its starches to sugars, making the leaves noticeably sweeter. This means your growing season is longer than you might expect, and your timing options are more flexible.
This guide gives you exact planting dates for both spring and fall crops, by zone.
When to Plant Kale by Zone
Kale is a cool-season crop that grows best when temperatures are between 45°F and 75°F. For spring plantings, start seeds or transplants outdoors 4–6 weeks before your last frost date. For fall plantings — often the better of the two seasons — count back 6–8 weeks from your first fall frost date.
| USDA Zone | Spring Planting | Fall Planting |
|---|---|---|
| Zone 3 | Apr 14 – Apr 28 | Jul 18 – Aug 1 |
| Zone 4 | Apr 4 – Apr 18 | Aug 3 – Aug 17 |
| Zone 5 | Mar 19 – Apr 2 | Aug 17 – Aug 31 |
| Zone 6 | Mar 4 – Mar 18 | Sep 1 – Sep 15 |
| Zone 7 | Feb 22 – Mar 8 | Sep 19 – Oct 3 |
| Zone 8 | Feb 6 – Feb 20 | Sep 29 – Oct 13 |
| Zone 9 | Jan 20 – Feb 3 | Oct 11 – Oct 25 |
| Zone 10 | Jan 1 – Feb 1 | Oct 25 – Nov 15 |
Spring Planting: Get It In Early
Spring kale must be harvested before summer heat triggers bolting. In zones 5–7, this means a relatively short spring window — typically 8–10 weeks of good growing before heat stress sets in. Start seeds indoors 5–6 weeks before transplant date for the earliest possible harvest.
Transplant outdoors 4–6 weeks before your last frost. Young kale plants tolerate frost down to the mid-20s°F. A hard freeze will damage them, but light frosts are fine and actually improve flavor even in spring.
Choose fast-maturing varieties for spring: ‘Red Russian’ (50–60 days) and ‘Dwarf Blue Curled’ (55 days) work well for spring crops when you need to beat the heat.
Fall Planting: The Better Season
Fall kale is often superior to spring kale in every way — better flavor, more productive, and less pressure from pests. The plants establish in the warmth of late summer and then harvest through cooling fall temperatures. In zones 6 and warmer, kale left in the ground can overwinter and provide early spring harvests as well.
The best fall kale varieties are larger and more productive: ‘Winterbor’ (60 days), ‘Lacinato’ (also called Dinosaur Kale, 62 days), and ‘Redbor’ (55 days). These also overwinter best in zones 6–8.
Direct sow fall kale in the garden in late summer, or start transplants indoors and set them out 4–6 weeks before first frost. The plants need 6–8 weeks of growth before hard frost arrives to be well-established.
Winter Kale in Mild Climates
In zones 7 and warmer, kale planted in fall can remain productive through the entire winter. The plants go semi-dormant in the coldest weeks but recover quickly. By late winter, as days lengthen, they produce a flush of sweet new growth before finally bolting in spring.
In zones 8–10, kale is essentially a year-round crop. Plant in fall, harvest all winter, and let it bolt in spring to collect seeds for the next planting.
Spacing and Planting Depth
Direct sow kale seeds 1/4 to 1/2 inch deep, 3 inches apart, then thin to 18–24 inches when seedlings are 3–4 inches tall. Kale grows into a large plant — it needs that space. Crowded plants produce smaller leaves and have more disease problems.
Transplants go in at the same 18–24 inch spacing. Plant slightly deeper than the nursery pot — burying the lower stem encourages better root development.
