Collard greens are the toughest brassica for a hot climate — a big, bold leafy green that keeps producing for months and actually improves after a cool night. This guide answers "when to plant collard greens zone 11" directly: when to sow, how to start it, what soil and spacing it needs, how to water and feed it, which neighbours help, which pests to watch, and when to harvest. Zone 11 is frost-free, with average winter lows of 40 to 50°F, so there is no last or first frost date to plan around — here you plant by heat and by the wet and dry seasons, not by frost. See the full planting calendar for the whole year, and check your local extension service for advice specific to your area.
Collard Greens at a glance in Zone 11
All figures below are broad published ranges from standard horticultural references, not exact figures for any variety or garden — they vary by variety, climate and soil. Use them to compare crops and to plan, not as promises.
| Detail | Collard Greens |
|---|---|
| Days to germinate | 7–10 |
| Days to maturity | 60–80 |
| Spacing (inches) | 12–18 |
| Soil pH | 6.0–7.5 |
| Sun | full sun |
| Sowing method | both |
| Cold tolerance | frost-tolerant |
| Water needs | moderate |
When to plant collard greens in Zone 11
Start collard greens in the cool season, roughly late autumn, so plants establish while the weather is mild. Collards are more heat-tolerant than most brassicas, and in Zone 11 they will often keep producing into the warm season if they have afternoon shade and steady water — but the best growth still comes in the cool months. With a published maturity range of 60–80 days, a cool-season sowing gives months of picking. Because the zone is frost-free, with winter lows of 40 to 50°F, there is no frost date to plan around — sow by temperature and season instead, and check your local extension service for the best window in your area. Collards are a biennial grown as an annual here; in the tropics they rarely survive a second year. Our November in Zone 11 guide shows what else to sow and harvest that month in Zone 11.
Starting collard greens
Sow collard seed directly or start it in trays — both work, and the published germination range is 7–10 days. Starting indoors gives you control over timing and protects seedlings from slugs; transplant when seedlings have three or four true leaves, after hardening them off. Space plants as shown in the table below — collards grow large, and crowded plants stay small and invite disease. Sow seed about half an inch deep and keep the bed moist until seedlings are up. Use the seed-starting calculator to time your sowing for the cool season.
Soil, spacing and sun
Collard greens want deep, fertile, well-drained soil with a soil pH of 6.0–7.5. Dig in plenty of compost before planting; collards are heavy feeders, and compost also helps sandy tropical soils hold moisture. They tolerate a wide range of soils but hate waterlogging, so raised beds or well-drained ground are best in the wet season. Mulch thickly to keep roots cool and moist and to suppress weeds. Collards grow big — give each plant room, and do not plant them where brassicas grew last season, since they share pests and diseases.
Watering and feeding
Collard greens need moderate, steady water. Water deeply at the base in the morning, keeping leaves dry to reduce disease in humid air, and mulch to hold moisture between waterings. In the dry season, water every few days; in the wet season, ease off and make sure beds drain. Feed every three or four weeks with a balanced liquid feed or compost tea — collards are hungry, and well-fed plants produce big, tender leaves. If older leaves yellow, pick them off; it is usually age or a dry spell, not disease.
Companion planting
Good companions for collard greens are marigolds, basil, onions and lettuce. Onions help deter cabbage pests, marigolds at the bed edge discourage soil pests, and lettuce can be grown between young collards as a catch crop. Basil attracts beneficial insects, and collards are good neighbours for beans, which fix nitrogen the collards use. Avoid planting collards next to other brassicas such as cabbage, broccoli or kale, since they share pests, and rotate brassicas to fresh ground each year to break the cycle of clubroot and cabbage worms. For a cooler-climate comparison, see how the same crop is timed in Zone 9.
Pests and problems
Watch for cabbage worms, aphids, flea beetles and slugs. Cabbage worms — the green caterpillars of the white butterfly — are the main enemy: check leaf undersides weekly and pick them off, or cover the bed with fine insect mesh from transplanting. Aphids cluster on young leaves and can be washed off with water. Flea beetles riddle young leaves with holes; mesh and moist soil keep them down. Slugs chew leaves at night in humid weather — check at dusk. Remove yellowing leaves promptly so pests have fewer places to hide.
Harvest and storage
Begin picking outer leaves when plants are well established, usually within the published maturity range of 60–80 days from sowing. Pick the lowest, largest leaves first, leaving the centre growing point intact — a plant harvested this way keeps producing for months. Young leaves are tender; older leaves are best cooked long and slow, which is the classic way to eat collards. Collards do not store well, so pick only what you need for a meal. In the fridge, unwashed leaves keep for several days wrapped loosely. If you are planning the rest of the bed, our guide to Brussels Sprouts in Zone 11 covers another crop from the same Zone 11 season.
Frequently asked questions
When should I plant collard greens in Zone 11?
In the cool season, roughly late autumn, so plants establish in mild weather. They tolerate more heat than most brassicas and often keep producing into the warm season with shade and water.
Are collard greens heat-tolerant?
More than most brassicas, yes. They will keep growing in warm weather that kills lettuce and spinach, though growth slows and pests increase. Afternoon shade and steady water help a lot.
Why are my collard leaves full of holes?
Usually cabbage worms or flea beetles. Cover the bed with fine insect mesh from transplanting, and check leaf undersides weekly for green caterpillars to pick off by hand.
Do collard greens need frost in Zone 11?
No. Zone 11 is frost-free, with winter lows of 40 to 50°F. A cool night sweetens the leaves, but frost is not needed — or available — here. Check your local extension service for local timing.