How to Grow Collards from Seed
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How to grow collards from seed comes down to four decisions: when to sow, how deep to cover the seed, how far apart the seedlings should stand, and when to harvest. Extension pages from North Carolina State, Illinois, Maryland and the University of Florida agree on most of them. Where they differ, especially on sowing depth, this guide shows both figures and does not pick a winner. Collards are a cool-season crop, which is why the calendar comes first.
Quick answer
- Sow in early spring or midsummer. Illinois Extension suggests an early spring sowing for summer harvest and a midsummer sowing for fall and early winter.
- Cover the seed lightly. Illinois says to sow 1/4 to 1/2 inch deep, while NC State Extension gives 1/2 to 3/4 inch and says never deeper than 1 inch.
- Choose spacing by harvest goal. NC State ties spacing to whether you cut young leaves or full plants, and Illinois thins to 6 inches and leaves about 18 inches.
- Expect roughly 70 to 90 days from seed to harvest, according to UF/IFAS Gardening Solutions. UMD Extension gives 40 to 80 days, depending on variety.
When to sow
NC State Extension says that “Collards are a cool-season crop that grows best during early spring or fall.” Its page advises planting seeds in early spring or midsummer, and planting transplants in early spring or late summer. It adds that a mature plant will withstand frosts and light to medium freezes.
Illinois Extension gives a similar calendar. Its page says to “Plant in early spring for summer harvest and again in midsummer for fall and early winter harvest.” It also says the plant “grows better in warm weather and can tolerate more cold weather in the late fall than any other member of the cabbage family.”
University of Maryland Extension gives a fall method that works for any crop with a known maturity time. Find the time to maturity, add 10 to 14 days, and sow that many days before the first fall frost. Its example uses a crop with 55 days to maturity, which means sowing 65 to 69 days before frost. For spring sowings, the same page says to plant seed as soon as the soil can be worked, about 3 to 4 weeks before the frost date.
The table below puts the timing side by side. Two of the four pages do not give days from seed, so the harvest figures come only from the other two.
| Source | Sowing guidance stated | Days to harvest stated |
|---|---|---|
| NC State Extension | Seed in early spring or midsummer | Not stated |
| Illinois Extension | Early spring for summer harvest; midsummer for fall and early winter | Not stated |
| UMD Extension | As soon as the soil can be worked in spring; fall sowing counted back from frost | 40 to 80 days from seed, depending on variety |
| UF/IFAS Gardening Solutions | Outdoors in fall and winter: September to April (North Florida), September to February (Central), September to January (South) | About 70 to 90 days from seed; about 50 to 70 days from transplants |
How deep to sow
Sowing depth is where the pages differ most. NC State Extension says: “Place seeds in moist soil 1/2 to 3/4 inch deep, never deeper than 1 inch.” Its page also asks that the top 3/4 inch of soil stay moist, but not saturated, while the seeds germinate. Illinois Extension is shallower. It says: “Sow the seeds 1/4 to 1/2 inch deep.”
UF/IFAS Gardening Solutions and University of Maryland Extension do not give a seeding depth in the pages we read. Both of the ranges that do appear sit within the top 3/4 inch of soil, so a light covering is the common ground.
Prepare the bed
NC State Extension recommends a soil test before planting. Its page says: “Soils should be well drained, rich in organic matter, and have a pH of 6.0 to 6.5.” It sets the timing for the bed as well: “At least seven days before planting, cover the bed with 2 inches of compost and work it in along with amendments recommended in the soil test report.” If you plan to grow greens in a raised bed, see our guide to vegetables to grow in raised beds.
UF/IFAS Gardening Solutions adds: “They prefer full sun and organic soil amendments like compost.” Its page says collards do well in moist soil and with a complete fertilizer that includes a moderate amount of nitrogen. Illinois Extension asks growers to keep soil moisture ample during hot summer periods.
NC State also gives the feeding timing. Apply fertilizer beside the plants three to five weeks after the seed comes up, or two to three weeks after transplanting. The page explains that leafy vegetables need quick, continuous growth and ample nitrogen for deep green color and tender growth.
Sow, thin and space
Spacing depends on the harvest you want, and NC State Extension lays it out by goal. Seed for young leaves goes 2 to 4 inches apart. Plants cut at half-grown size go 10 to 15 inches apart, and plants harvested full-grown go 15 to 18 inches apart. The page also says: “Collard greens grown in beds two to four plants wide with 12 to 18 inches between beds provide greater yields and improved quality.”
| Harvest goal (NC State Extension) | Spacing stated |
|---|---|
| Young leaves | 2 to 4 inches apart |
| Half-grown plants | 10 to 15 inches apart |
| Full-grown plants | 15 to 18 inches apart |
Illinois Extension uses a thinning route. Sow the seed, then thin the seedlings to 6 inches apart, let them grow until they begin to touch, and harvest whole plants so the remaining plants stand about 18 inches apart. Thinned plants can be eaten. The page also says: “Allow at least 3 feet between rows because plants become large.”
University of Maryland Extension gives a wider in-row range of 12 to 24 inches for large plants, with 30 to 36 inches between rows. It notes that closer spacing of 2 to 4 inches produces more small plants that can be harvested repeatedly. NC State states the principle behind this: “Spacing depends on when the crop will be harvested.” So choose the spacing before you sow.
Harvest for flavor and regrowth
Illinois Extension says all the green parts of the plant are edible and can be harvested at any point in the season. Plants grown 6 inches apart can be cut at ground level when they reach 6 to 10 inches tall. Wider-spaced plants are harvested by picking the larger leaves once they are 10 to 12 inches tall, which lets the younger leaves keep developing. Some gardeners cut the inner cluster of young growth instead, which the page describes as a loose head.
UF/IFAS Gardening Solutions says to pick the older outer leaves so the center keeps producing. It also points to harvesting at the right size: “For the best-tasting collards, harvest the leaves when they are young (about 10 to 12 inches long), before they become tough and woody.” Its tip for a longer season is to stagger the planting every couple of weeks, which allows continuous harvesting for many months.
Frost changes the flavor. Illinois Extension says that “As with other cole crops, frost improves the flavor in the fall.” UF/IFAS adds: “Frosts can actually convert the starches into sugar and improve the taste of the greens.” It also suggests picking collards during cold months, after the first frost, which is the practical step that page recommends.
Store the harvest carefully. UF/IFAS says: “It’s best to store the leaves whole and unwashed in the refrigerator until you are ready to use them.” The same page says they should last from a few days up to a week, and advises washing them thoroughly in several rounds of water before cooking so the food is not gritty.
Choose a variety
UF/IFAS Gardening Solutions names cultivars that do well in Florida. ‘Georgia Southern’ has tender, large leaves. ‘Vates’ is more compact and suits smaller gardens. ‘Alabama Blue’ has bluish leaves with streaks of purple. ‘Champion’ has improved cold tolerance and disease resistance, and ‘Top Bunch’ replenishes quickly after harvest. Because the list is written for Florida, check your local extension office before choosing for another region. For a bed layout that fits several crops, see our guide to companion planting in a raised bed layout.
Scout the leaves and keep weeds down
Illinois Extension asks growers to watch the undersides of the leaves for aphid colonies. It describes three cabbage worm species that attack the leaves, and it says caterpillars can ruin a crop if they go uncontrolled. The page also notes that fall plantings often suffer more, because pest numbers have had several months to build. UF/IFAS Gardening Solutions says hand-pulling weeds is a good way to keep collard greens healthy.
This guide does not give treatment advice. The steps the sources support are watching the leaves and pulling weeds by hand. For any control measure, check with your local extension office before you act.
Mistakes to avoid
- Sowing too deep. NC State Extension says never deeper than 1 inch, and Illinois gives a shallower range.
- Skipping the thinning step. Illinois thins to 6 inches first, then leaves about 18 inches between the plants you keep.
- Spacing for full heads when you want baby leaves. NC State ties spacing to the harvest goal.
- Letting the seedbed dry out. NC State asks that the top 3/4 inch stay moist, not saturated, during germination.
- Waiting too long to pick. UF/IFAS says to harvest young leaves before they become tough and woody.
- Washing leaves before storage. UF/IFAS says to store them whole and unwashed.
How we chose
This guide draws on four university extension pages: NC State Extension, Illinois Extension, UF/IFAS Gardening Solutions and University of Maryland Extension. We opened each page on 2026-10-23 and cited only facts the page states. We did not use seed-company pages or commercial growing guides for any figure, even where they agreed with the extension pages. Where the pages disagree, we show both figures and do not rank them.
What we could not verify
We could not confirm one sowing depth or one days-to-harvest figure, because the pages do not agree. The UF/IFAS page describes Florida planting windows, which may not match your region. This guide does not cover container growing.
What the sources do not say
The NC State and Illinois pages do not give days from seed, so the harvest figures above come from the UF/IFAS and UMD pages only. Neither UF/IFAS nor UMD gives a seeding depth in the pages we read. Nothing here is a product claim, and no seed brand is recommended.
Frequently asked questions
How long does it take to grow collards from seed?
UF/IFAS Gardening Solutions says plants grown from seed are generally ready in 70 to 90 days, and about 50 to 70 days from transplants. UMD Extension gives 40 to 80 days from seed, depending on variety. Because the two ranges differ, check the days on your seed packet as well.
How deep should I sow collard seeds?
NC State Extension recommends 1/2 to 3/4 inch, and never deeper than 1 inch. Illinois Extension recommends 1/4 to 1/2 inch. Cover the seed lightly and keep the top 3/4 inch moist while it germinates.
How far apart should collards stand?
It depends on the harvest. NC State Extension gives 2 to 4 inches for young leaves, 10 to 15 inches for half-grown plants and 15 to 18 inches for full-grown plants. Illinois Extension thins to 6 inches and leaves about 18 inches. UF/IFAS Gardening Solutions suggests 12 to 24 inches apart.
When is the best time to sow collards?
Illinois Extension recommends an early spring sowing for summer harvest and a midsummer sowing for fall and early winter harvest. NC State Extension gives the same spring and midsummer windows. For fall, the UMD Extension method counts back from the first frost, using days to maturity plus 10 to 14 days.
Why do collards taste better after frost?
UF/IFAS Gardening Solutions says frosts can convert the starches into sugar and improve the taste of the greens. Illinois Extension notes that frost improves flavor in the fall, as it does for other cole crops. The practical step the UF/IFAS page gives is to pick after the first frost.
Bottom line
Sow in early spring or midsummer, cover the seed lightly, thin to the spacing your harvest needs, and pick the young outer leaves.
Sources
- https://content.ces.ncsu.edu/publication/collard-greens (opened 2026-10-23)
- https://extension.illinois.edu/gardening/collard (opened 2026-10-23)
- https://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/collards/ (opened 2026-10-23)
- https://extension.umd.edu/resource/growing-leafy-greens-home-garden (opened 2026-10-23)
