GardenBiennial Leafy Green · zones 2–11 · 12 varieties
Collard
Brassica oleracea Collards Group
Brassicaceae — the same plant family as cabbage, radish, broccoli, cauliflower and 12 more here. Relatives share pests and diseases, which is why rotation plans group by family.
Collard (Brassica oleracea Collards Group) is a biennial leafy green for USDA zones 2–11. It wants full sun and pH 6–6.5 soil, with about 1–1.5 in of water weekly. It matures in about 70–90 days from sowing, or 50–70 days from setting out a transplant. Watch for aphids and black rot. Below: its full sourced profile from 12 extension sources, plus a planting calendar timed to your frost dates.
Typical dates for zone 6b — set your zone or ZIP for yours. This calendar assumes the crop is started indoors. Timing is a guide from the crop's sourced growth stages; confirm with your local frost dates and extension before you sow.
What we will not put a number on
We do not give a feeding rate for this crop, and that is deliberate rather than a gap. The figures published by extension services are pounds of nitrogen per acre for a production field — they do not convert safely to a raised bed or a pot without knowing your soil test and your fertilizer's analysis, and guessing errs toward burning roots. It is also why every chart you find online disagrees with the next one.
We give watering as a depth per week rather than gallons per plant, because that is how it is actually measured and how the published figures are written. A gallons-per-plant number depends on your spacing, your soil and whether the plant is in a pot — so it would look more precise than it is.
Site & soil
- Hardiness zones
- 2–11
- Sun
- Full sun
- Soil pH
- 6–6.5
- Soil texture
- Loam, Well drained
- Frost tolerance
- Hardy
No published figure for the temperature frost starts to hurt it and a heat limit. We looked — where a number is missing here it is missing from the research, not skipped. The crop’s frost and heat tolerance above still applies.
The plant
- Mature height
- 1–6 ft
- Mature spread
- 1–2 ft
- Growth rate
- Fastest
- Spacing in row
- 12–24 in
- Between rows
- 30–36 in
- Planting depth
- 0.25–0.5 in
- Container size
- 4–6 gal — low end is the minimum, high end is better
- Support
- Self-supportingest
- Grown from
- Direct sow, Transplant
Water & feeding
- Water needs
- Moderate
- Water per week
- 1–1.5 in/wk
- Critical water
- Establishmentest
- Feeding
- Moderate
Timing & fruiting
- Days to maturity
- 70–90 days from seed · 50–70 days from transplant
- Harvest cues
- Rapid leaf growthest
- Survives in the ground down to
- 20 °F
Planted again for autumn
- South Carolina — Piedmont
- Aug 1 – Sep 30
- South Carolina — Coastal Plain
- Aug 1 – Oct 30
Published by the extension service for its own regions, and quoted here for those regions only — converting them would mean assuming a frost date somewhere else. The chart says when, not whether to sow seed or set out plants, so we do not either. Only South Carolina so far.
- Set plants out by
- early Sep typical · zone 6b
50 days to maturity from setting a plant out — that is what our sources measure for this crop, so this is a date for planting out and not a sowing date, counted back from the first frost above. Not published for anywhere in particular: it is your own frost date and this crop's own figure, which is why it works wherever you are. A days-to-maturity figure is a catalog number for a good season rather than a promise, and a cold month moves it.
Edible parts per source: leaf.
Compiled from the extensions cited below. Which ones actually show up depends on your region — your extension's local list is the last word.
Open one and add it to your garden — it lights up here. The rest of the 12 are in the full list below.
| Variety | Type | Days | Color | What it is known for |
|---|---|---|---|---|
| Alabama Blue Heirloom | 75 | Green, Purple | Truelove Seeds describes this astakes the cold · takes the heat · slow to run to seed in heat | |
| Cascade Glaze Heirloom | Glaze | 60 | Green | Fedco Seeds describes this astakes the cold · takes the heat |
| Champion | Vates | 60 | Green | Urban Farmer describes this asslow to run to seed in heat · takes the cold |
| Flash F1 | Vates | 55 | Green | Johnny's Selected Seeds describes this asslow to run to seed in heat |
| Georgia Southern Heirloom | Georgia | 70 | Green | Sow True Seed describes this astakes the cold · takes the heat |
| Green Glaze Heirloom | Glaze | 79 | Green | Truelove Seeds describes this astakes the cold |
| Morris Heading Heirloom | Morris Heading | 75–85 | True Leaf Market describes this astakes the cold · takes the heat · slow to run to seed in heat | |
| Ole Timey Blue Heirloom | 60–80 | Green, Purple | ||
| Tiger F1 | Georgia | 69 | Green | Weseeds describes this astakes the cold · takes the heat |
| Top Bunch 2.0 F1 | Top Bunch | 50 | Green | Johnny's Selected Seeds describes this astakes the heat |
| Vates Heirloom | Vates | 75 | Green | Urban Farmer describes this asslow to run to seed in heat · takes the cold |
| Yellow Cabbage Heirloom | Cabbage Collard | 60–80 | Green | Ujamaa Seeds describes this astakes the cold |
- Clemson Cooperative Extension, Home & Garden Information Center
- Harvest to Table
- Missouri Botanical Garden
- NC State Extension
- University of Florida IFAS Extension
- University of Illinois Extension
- University of Maryland Extension
- University of Minnesota Extension
We compile bare facts from these university-extension and horticultural sources, never copied prose. 17 of the 21 values on this page carry a citation. The rest are marked est; hover one and it says why — either nobody publishes a figure we could point at, or a person set it and attached no source. Figures vary with climate and seed source; confirm with your local extension before you buy.
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