How to Grow Collard Greens
Brassica oleracea var. viridis
Collard greens are a hardy, heat-tolerant brassica for full sun and fertile, moisture-retentive soil. Sow from early spring or late summer for autumn and winter harvests. More heat-tolerant than kale, they thrive where other brassicas bolt. Harvest lower leaves regularly once they reach hand-size; frost sweetens the flavour. Cover with insect mesh to deter cabbage whites and aphids. Plants can produce for many months, cropping through winter in mild areas. Rotate beds to reduce clubroot risk.
When to Start
Direct sow outdoors as soon as soil reaches 7°C — typically early to mid spring. Can also be started indoors 5 weeks earlier for a head start.
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Growth Stages
Approximate days from start
Care Essentials
- Nitrogen-rich feed at planting. Side-dress with compost monthly during growing season.
- Extremely nutritious and heat-tolerant. A staple of Southern US cuisine, more tolerant of heat and cold than most brassicas.
Growing Conditions
- Min. soil temperature
- 7°C+
- Germination temperature
- 10–30°C
- Sow indoors
- —
- Transplant out
- —
- First harvest
- —
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Spacing & Planting
| Plant spacing | 45 cm |
| Row spacing | 60 cm |
| Sow depth | 1 cm |
| Mature height | 90 cm |
| Mature spread | 60 cm |
Large plants need room to spread. Can plant closer (30cm) for baby leaf harvests.
Growing Conditions
| Min. soil temperature | 7°C |
| Germination temperature | 10–30°C |
| Base growth temperature | 4°C |
| Min. daylength to start | 8.5h |
| Photoperiod sensitivity | day neutral |
Frequently Asked Questions
- How far apart should I plant Collard Greens?
- Plant Collard Greens 45cm apart with 60cm between rows.
- When can I harvest Collard Greens?
- Collard Greens is ready to harvest approximately 55 days after transplanting.
- Is Collard Greens frost hardy?
- Collard Greens is classified as Hardy.
