Broadfork™

Crop guide

Cabbage

Cabbage starts indoors in late winter and goes out around the last frost. Cut the head when it's solid, before it splits.

Grown in Ohio, zone 6a. Your frost dates move the calendar; the signals don't. Broadfork goes by where your garden is, not its zone: frost dates for your ZIP code in the US, or the ones you type in anywhere else.

Seven minutes to read. Each section stands on its own.

A cabbage plant with a firm pale green head in a rosette of broad blue-green outer leaves, its short stem and roots in the soil below.
What you plant
A transplant. Start the seed indoors 6 to 8 weeks before the frost-free date; the plants go out 4 to 6 weeks after they come up.
When
Around the last frost. Data with a last frost about April 22 sets the plants out from April 10 to 25.
How deep
Seed 1/4 to 1/2 inch deep. Transplants at the depth they grew in the pot.
How far apart
12 inches apart in rows 24 inches apart, or 15 to 18 inches each way in a bed. The app plants cabbage 1 per square foot, 12 inches apart.
Sun and soil
Not in our rows yet.
Frost
Hardy. Hardened plants take a light frost, and mature plants take heavy frosts down to about 24 °F.
Family
Brassicaceae, the mustard family, with broccoli, cauliflower, kale, collards, kohlrabi and Brussels sprouts.
Harvest
When the head is solid and tight, before it splits. Most data gives 60 to 80 days from transplanting; early kinds can be ready in 45, long-season kinds take 100 or more.
Soil pH
6.0 to 6.8, which also discourages clubroot. The data runs from 5.5 to 7.5.
winterspringsummerfall start seed indoors6 to 8 weeks beforethe frost-free date set outaround the last frost cut the heads60 to 80 days after setting out storea cellar at 32 to 40 °F
  1. winterStart the seed indoors 6 to 8 weeks before the frost-free date.
  2. springSet the plants out around the last frost.
  3. summerCut the heads 60 to 80 days after setting out.
  4. fallKeep them for months in a root cellar at 32 to 40 °F.
Cabbage's year. It is set by the last frost, not the month: the seed starts counting back from it and the plants go out around it. The green bar is the cutting.

Starting and planting#

Start the seed indoors 6 to 8 weeks before the frost-free date, 1/4 to 1/2 inch deep. The plants are ready to set out 4 to 6 weeks after they come up.

Don't hold them too long, or too cold. Young plants that sit for long below 50 to 55 °F are likely to bolt later, and 10 or more days at 35 to 50 °F can make cabbage flower early. Set out plants about 4 weeks old, and don't leave them below 50 °F for a week or more.

Harden them off gently. Cabbage is hardier than the warm-season crops and goes out sooner, but hardened too hard, it bolts.

From the beds in OhioKeep an eye on the trays once they're outside. Cabbage-family pests find the seedlings fast and lay eggs so tiny you'll miss them, and those go straight into the garden as worms.

Set them out around the last frost: data with a last frost about April 22 plants them from April 10 to 25. Hardened plants take a light frost.

Plant them at the depth they grew in the pot, water them in, and give each 1 cup of starter solution.

Space them 12 inches apart in rows 24 inches apart, or 15 to 18 inches each way in a bed.

Set out a summer planting on a cloudy, overcast or rainy day.

In Broadfork On a cabbage's crop page, and beside Companions on the add form, the app gives the seed depth and sets the plants at the depth they grew in the pot.

top of the root balllevel with the soil:the depth it grew in the potthen 1 cup of starter 12 inin rows 24 in apart
In the ground. Set each plant at the depth it grew in the pot and give it 1 cup of starter. Space them 12 inches apart in rows 24 inches apart.

The season in between#

Net the plants the day they go in. Flea beetles come in early spring, cabbage maggot flies lay in early to mid-May, and the white butterflies whose young are cabbage worms are out from about mid-May. Seal the edges with soil, and leave the netting on until harvest; only a plant kept for seed flowers and needs it off.

In Broadfork When a cabbage goes in, the app puts bug netting on your list for that day, to stay on until harvest.

A row cover also keeps off cutworms, loopers and harlequin bugs.

Harvest#

Cut the heads while they're solid and tight, before they crack or split. Most data gives 60 to 80 days from transplanting; early kinds can be ready in 45, long-season kinds take 100 or more.

To hold a ready head a little longer, cut some of its roots with a spade, or twist the stalk to break a few. No data says how many days that buys.

In direct sun, heads sunblister and lose weight.

Cut close under the head and leave the loose outer leaves: small heads, 2 to 4 inches across, can grow from the stump. The data splits here: other data says cabbage won't form side shoots, and pulls the plants.

A medium head, about 5-3/4 inches across, weighs about 2 pounds.

Storing#

Cabbage can keep for months in a root cellar, ideally at 32 to 40 °F.

Saving seed#

Cabbage makes seed in its second year. Dig the plants or carry them over winter, store them at 32 to 45 °F, and replant them; the seed forms in dry pods.

It crosses with broccoli, kale, cauliflower, Brussels sprouts, kohlrabi and collards, all one species, so keep varieties a quarter mile apart, or half a mile in some data. That puts it among the hardest seed to save.

The seed is ripe when the plants dry out and turn orange-brown. Open a few of the oldest pods, which brown first. No data gives the days from flower to ripe seed.

Kept cold and sealed, the seed lasts about 4 years; some data says 3. The seed-saving guide shows how to store it.

Which cabbage#

Two kinds, by season: short-season cabbage, ready as soon as 45 days after transplanting, and long-season, at 100 days or more.

In the app's catalog, among others: Golden Acre, Early Jersey Wakefield, Copenhagen Market, Red Acre, Stone Head and Ruby Perfection.

What goes wrong#

Where it goes next year#

Keep cabbage and the rest of its family out of a bed for 4 years.

Data plants a legume, such as beans or peas, after a heavy nitrogen feeder like cabbage.

In Broadfork The bed's rotation card counts the rest years for you and says which families are clear to go back in.

Every number on this page comes from a published extension source.

Sources for this guide: University of Minnesota Extension, University of Illinois Extension, Clemson Cooperative Extension, Ohio State University Extension, NC State Extension, Utah State University Extension, Iowa State University Extension and Outreach, New Mexico State, University of California, University of Kentucky Cooperative Extension, University of Maryland Extension, University of Missouri Extension, University of New Hampshire Extension, University of Wisconsin-Madison Division of Extension, Washington State University Extension, Colorado State University Extension, Oklahoma State University Extension, Oregon State University Extension, Penn State Extension, Purdue Extension, SDSU Extension, Texas A&M AgriLife Extension, UMass Extension, University of Georgia Extension, University of Nebraska–Lincoln Extension, WVU Extension.

The documents behind this guide (61)

Updated 11/11/2026 · Checked against our sources 11/12/2026

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