š„¬When to Plant Kale in USDA Zone 6a (2026 Guide)
Frost actually sweetens it. Plant early spring and again for fall. Here is the cool-season planting schedule for kale in zone 6a (covering areas like St. Louis MO, Philadelphia PA). All dates are based on 2026 frost data for your zone.
Start Seeds Indoors
Mar 16
Direct sow or transplant
Mar 30
Harvest From
May 24
Because kale is a cool-season crop, it tolerates light frost and can go out around Mar 30, before zone 6a's average last frost on Apr 20.
- Type: Cool-season
- Method: Direct sow or transplant
- Days to harvest: 55
- Spacing: 12" apart
- Sun: Full sun to part shade
- Zone 6a frost: Apr 20 ā Oct 15
- Season length: ~178 days
- Companions: beets, onion, herbs
Growing kale in zone 6a
Zone 6a has an average last spring frost around Apr 20 and a first fall frost around Oct 15, giving roughly 178 frost-free growing days. That window comfortably fits kale's 55-day cycle, with room for a second succession planting if you time it right.
Get a head start by sowing seeds indoors around Mar 16, roughly 5 weeks before your last frost. Move the seedlings outside around Mar 30. Give each plant about 12 inches of space in full sun to part shade.
Zone 6a specific growing notes
In zone 6a (St. Louis MO, Philadelphia PA), your 178-day growing season means kale should be one of your first spring plantings. Cool-season crops thrive in the mild part of your growing window. Monitor soil temperature ā kale germinates best when soil is 40-75Ā°F.
Your first fall frost around Oct 15 means your last possible harvest is roughly late Oct. For a continuous supply, consider succession planting every 2-3 weeks from Mar 30 through mid-season.
Pro tip for kale
Frost converts starches to sugarākale harvested after a light freeze tastes noticeably sweeter. Harvest the oldest outer leaves first and the plant keeps producing from the center for months.
Troubleshooting kale
Cabbage aphids cluster in dense gray colonies inside leaf crevices and growing tips. A strong jet of water knocks most off. For persistent infestations, insecticidal soap or neem oil applied to leaf undersides works well.
Growing kale in containers
One plant per 3-gallon pot minimum. Kale is ornamental enough for mixed flower plantersāvarieties like 'Red Russian' and 'Lacinato' (dinosaur kale) look striking alongside annual flowers.
Can you plant kale twice a year?
Yesāspring and fall crops are standard practice. In zones 5+, start fall kale indoors in early July and transplant by early August. Mature kale survives winter down to zone 5 with minimal protection.
Frequently asked questions
When should I plant kale in zone 6a?
Direct sow or transplant around Mar 30. If starting from seed indoors, sow around Mar 16. Because kale is a cool-season crop, it tolerates light frost and can go out around Mar 30, before zone 6a's average last frost on Apr 20.
How long does kale take to grow in zone 6a?
About 55 days from sowing to first harvest. A Mar 30 planting in zone 6a is typically ready to pick from around May 24. Zone 6a has about 178 frost-free days ā plenty of time for a second succession planting.
How far apart should I space kale?
Space kale about 12 inches apart in full sun to part shade. This gives each plant enough room for roots to spread and leaves to catch sunlight without competing.
What is the best tip for growing kale?
Frost converts starches to sugarākale harvested after a light freeze tastes noticeably sweeter. Harvest the oldest outer leaves first and the plant keeps producing from the center for months.
What are common problems with kale and how do I fix them?
Cabbage aphids cluster in dense gray colonies inside leaf crevices and growing tips. A strong jet of water knocks most off. For persistent infestations, insecticidal soap or neem oil applied to leaf undersides works well.
Can I grow kale in a container?
One plant per 3-gallon pot minimum. Kale is ornamental enough for mixed flower plantersāvarieties like 'Red Russian' and 'Lacinato' (dinosaur kale) look striking alongside annual flowers.
Can I plant a second crop of kale for fall harvest?
Yesāspring and fall crops are standard practice. In zones 5+, start fall kale indoors in early July and transplant by early August. Mature kale survives winter down to zone 5 with minimal protection.
What grows well next to kale?
Good companion plants for kale are beets, onion, herbs. Avoid planting near warm-season crops that compete for space and nutrients. Kale also benefits from crop rotation ā do not plant it in the same spot year after year.