Cabbage is a hardy, cool-season crop. Cabbage is best planted in early spring or mid-to-late summer. Cabbage thrives in temperatures between 65°F and 75°F (18-24°C) and can withstand cold temperatures down to 25°F (-4°C).
Cabbage seedlings can be set in the garden 4 weeks before the last frost in spring. You can plant cabbage seeds in flats inside 4 to 6 weeks before you put the seedlings outside, which is 8 to 10 weeks before the last frost. The minimum soil temperature for cabbage is slightly above 40°F (4°C).
To grow cabbage where summers are warm, sow the seed of a fast-maturing variety in early spring. Where summers are cool, sow seed in mid-to-late spring for a fall and early winter harvest. Where summers are very warm or hot, sow seed in midsummer for a late fall and winter harvest.
Cabbage grows best at temperatures between 40° and 75°F (4°-24°C). Cooler temperatures and warmer temperatures can cause cabbages to bolt and go to seed. Choose a variety (see list below) that will come to harvest before adverse temperatures set in.
Expect cabbage seeds to germinate at nearly 100 percent. You may want to use tweezers to place seeds in the flat at 2-inch (5cm) intervals. If seeds come up crowded, transplant some to another flat otherwise the seedlings will become leggy and weak.
If you live somewhere where it doesn’t get above 70°F (21°C) in the summer, plant succession crops every three weeks to make sure you always have tender cabbage.
Cabbage has very shallow roots, so keep the top few inches of soil from drying out. Fluctuations in soil moisture after the heads have formed can cause heads to split.
There are many varieties of cabbage to choose from—savoy, looseleaf, ballhead, red, green, purple, or white. Some varieties mature quickly, others take longer. Some are suited for warm regions, others can withstand freezing winters.
Growing crunchy flavorful cabbages starts with nurturing young seedlings indoors. Starting cabbage from seed indoors allows you to get a head start on the growing season. You can transplant sturdy cabbage starts into your vegetable garden weeks before sowing seeds directly outdoors. With the right techniques starting cabbage seeds indoors is easy and rewarding.
When to Sow Cabbage Seeds Indoors
Timing is key when starting cabbage seeds indoors. Cabbage seedlings need 4-6 weeks of growth before they can be transplanted outside after the threat of frost has passed.
In northern regions sow cabbage seeds indoors 4-6 weeks before your estimated last spring frost date. In southern areas with mild winters start seeds in late summer or early fall for growing into winter.
Aim to time transplanting cabbage seedlings into the garden about 1-2 months before the first expected 100°F (38°C) weather. Cabbage grows best in cool conditions.
Selecting the Best Cabbage Varieties for Indoor Starts
Choose early-maturing cabbage varieties for starting indoors and transplanting. Quick-growing types will produce heads before summer heat strikes.
Some excellent cabbage varieties for indoor seed-starting include:
- Early Jersey Wakefield (62 days to maturity)
- Stonehead (68 days)
- Copenhagen Market (75 days)
- Golden Acre (65 days)
Mini cabbage varieties like Caraflex also work well when started indoors.
How to Sow Cabbage Seeds for Indoor Seedlings
Cabbage seeds can be started in seed trays, flats, pots or other containers with drainage holes. Here are step-by-step tips:
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Fill containers with a sterile, soilless seed-starting mix. Gently firm the mix.
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Sow seeds 1⁄4 inch deep in rows or cells, spacing 1-2 inches apart.
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Cover seeds lightly with seed-starting mix or vermiculite.
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Water gently to moisten the soil mix.
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Place containers in a warm area (70-80°F) with bright light.
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Keep soil evenly moist but not sopping wet as seeds germinate.
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Cabbage sprouts should emerge in 5-10 days.
Caring for Young Cabbage Seedlings
As soon as cabbage sprouts emerge, move seedling flats to a sunny window or place under grow lights. Seedlings need 14-16 hours of bright light daily.
Keep the soil moist but not wet to encourage healthy root growth. Mist leaves to boost humidity around young plants.
Once cabbage seedlings have 2-3 true leaves, thin to one plant per cell or pot. Handle carefully by the leaves, not the stem.
Feed cabbage seedlings with a diluted organic liquid fertilizer or compost tea once a week.
Hardening Off Cabbage Transplants
Cabbage seedlings need a week or two to transition from indoors to outdoors through the hardening off process. Slowly expose plants to sun, wind and cooler temperatures.
Begin by placing flats outdoors in shady spots for a few hours daily. Gradually increase time spent outdoors and introduce more sun over 7-10 days.
Leave cabbage plants outside overnight before transplanting into the garden. Avoid transplanting on extremely hot, sunny or windy days.
Transplanting Hardened Cabbage Seedlings
Space cabbage transplants 12-24 inches apart in rows, with 24-36 inches between rows. Dig holes the same depth as seedling root balls.
Carefully remove plants from containers, disturbing roots as little as possible. Place in holes and fill with soil, firming around stems.
Water transplants well and provide shade for a few days if temperatures will be over 80°F. Keep soil consistently moist as plants establish.
Enjoying a Bountiful Cabbage Harvest
With proper care indoors and attentive transplanting and planting, cabbage seedlings started indoors will flourish into hearty heads for harvesting.
Stagger planting dates every 2-3 weeks for a continuous supply. Harvest cabbages when heads feel firm and reach desired size for fresh eating or storage crops.
With the right timing and techniques, growing crunchy, savory cabbages from indoor-started seeds is easy and rewarding!
Cabbage sowing and planting tips
- Start cabbage from seed or transplants.
- Cabbage seeds are viable for 4 years.
- For a fall or winter crop, start seeds indoors 6 to 4 weeks before the last frost in the spring or 12 to 10 weeks before the first frost in the fall.
- Start seeds in individual pots or flats.
- Plant seeds ¼ to ½ inch (6–8 mm) deep in the seed-starting mix.
- Keep the mix moist but not wet.
- If the temperature is around 77°F (25°C), the seeds should sprout in 5 to 8 days.
- Plant seedlings in the garden when they are 4 to 6 inches (10 to 15 cm) tall and have two to four leaves. Do this after the temperature reaches 50°F (10°C). Firm the transplants into the soil by hand.
- Cabbage prefers a soil pH range of 6. 0 to 7. 5; a pH of 7. 2 to 7. There is a better chance of getting clubroot disease if you have had it before.
- Plant seedlings farther apart than they were in pots or flats when you move them.
- Grow cabbage in full sun for best yield—tolerates partial shade.
- Before transplanting, add 3 to 4 inches (7 to 10 cm) of compost and well-aged manure to the planting bed. Cabbage needs soil that is loose but holds water.
- Avoid planting where cabbage family crops have grown recently.
- Space plants 12 to 24 inches (30-60 cm) apart.
- Space rows 24-42 inches (60-106 cm) apart.
- Cover the seedlings with a cloche, plastic tunnel, or cold frame for two to three weeks after planting to keep them warm.
- Use an organic fertilizer, like fish emulsion half-strength, to feed the plants.
- Pests that are often eaten by plants include aphids, cabbage worms, loopers, and cutworms.
Interplanting: Interplant cabbage with beets, green onions, spinach, and herbs.
Container Growing: Choose a container with a minimum depth of 20 inches (51 cm).
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Cabbage patch near harvest
Planting cabbage for spring harvest
- Eight to ten weeks before the last frost in the spring, start seeds indoors so they can be moved outside later.
- Set transplants out in the garden or plant seeds directly in a plastic tunnel or cold frame 4 to 6 weeks before the last frost in the spring.
- In the spring, 3–4 weeks before the last frost, direct sow in the garden when the soil is at least 45°F.
How to Start Cabbage (and other brassicas) from Seed Indoors
FAQ
What is the best way to germinate cabbage seeds?
When should you start cabbage seeds indoors?
Do cabbage seeds need darkness to germinate?
How do you start cabbage seeds in seed trays?
When should I start a cabbage plant?
One of the earliest to sow from Late Feb onwards under cover. A popular and reliable general purpose cabbage producing an early compact ballhead with deep flavour and excellent quality. One of the earliest to sow from Late Feb onwards under cover. Start seed indoors or in greenhouse in early spring Feb onwards (5-7 weeks before planting outdoors).
Can you grow cabbage from seed?
Grow cabbage from seed for your summer salads, fall soups and stews, and winter sauerkraut. Summer cabbages, sweet and crisp, arrive just in time for cool, summer coleslaws. Grow red and green for a great color combination. If you have a small family or limited growing space, try growing a compact variety.
When can you plant cabbage seeds indoors?
You can start indoor cabbage seed planting in early or mid-April for a May planting. The passage also mentions that April is the perfect time for sowing many seeds, including cabbage, no matter which climate zone you inhabit.