How to Grow Collard Greens
Brassica oleracea var. viridis
Collard greens are hardy brassicas valued for their tender leaves and ability to thrive in cool weather. Gardeners prize them for continuous harvests that withstand light frosts, providing nutritious greens well into winter months.
📷 Wikipedia: Collard (plant)Starting Collard Greens: indoors or direct sow?
🏠 Start indoors 4 weeks before your last spring frost, then move the seedlings outside.
Start seeds indoors four weeks before the last frost, then transplant seedlings outdoors once all danger of hard frost has passed.
Soil, care & harvest
Prepare loose soil with a pH between 6.0 and 7.5. Sow seeds indoors or directly outdoors two to six weeks before your last spring frost date. Press seeds gently into the soil at a depth of about half an inch. Germination typically occurs within five to ten days, after which seedlings are ready for transplanting if started indoors.
Space plants eighteen to twenty-four inches apart to ensure good air circulation. Water moderately to keep the soil consistently moist but not soggy. Apply a layer of mulch around the base to retain moisture and suppress weeds. Feed regularly with a balanced fertilizer to support steady leaf production throughout the season.
Watch for common brassica pests like cabbage loopers and aphids; use row covers or insecticidal soap for control. Prevent diseases by avoiding overhead watering and ensuring good airflow. Harvest leaves when they are mature, usually sixty to eighty days after sowing. Cut outer leaves first to encourage further growth from the center.
When to Plant Collard Greens
Planting windows vary by USDA hardiness zone. Look up yours by ZIP code.
| Zone | Start Indoors | Direct Sow | Harvest |
|---|---|---|---|
| Zone 1 | April – May | June – July | August – September |
| Zone 2 | April – May | May – July | July – September |
| Zone 3 | March – April | May – June | July – October |
| Zone 4 | March – April | April – June | July – October |
| Zone 5 | February – March | April – May | June – November |
| Zone 6 | February – March | April – May | June – November |
| Zone 7 | February – March | March – May | May – November |
| Zone 8 | January – February | March – April | May – December |
| Zone 9 | January | February – March | April – December |
| Zone 10 | January | January – March | March – December |
| Zone 11 | January | January – February | February – December |
| Zone 12 | January | January – February | February – December |
| Zone 13 | January | January – February | February – December |
