Growing Cabbage Seedlings from Seed
If you are using cabbage seeds to start seedlings for early spring planting, you should sow the seeds six to eight weeks before the last frost date for your area.
Garden soil is too heavy for starting seeds in containers. Instead, use a balanced, loamy or sandy potting soil with a pH of 6.5 to 6.8. Choose a soil that’s blended for vegetables or vegetables and herbs.
Space the seeds 2 inches apart and cover them with 1/4 inch of soil.
To encourage germination, choose a location where the temperature remains between 65-75°F (18-24°C).
Even though they are under a covering of soil, cabbage seeds also need light to germinate, so place them in a sunny location or use a cool white florescent light or a grow light.
You should keep the soil evenly moist but don’t overwater so that the soil becomes muddy or water stands on the surface in the containers.
Your seedlings should have developed three or four leaves and be ready for transplanting two to three weeks before the last frost date for your area.
A week or two before you plan to transplant your seedlings begin to harden them or acclimate them to conditions outdoors:
- Choose a cloudy day, and set your plants outside for about two hours.
- On the second day of hardening, extend the time you leave your cabbage outside, and leave them in the morning sun for about an hour.
- On each successive day, gradually lengthen the time you leave your cabbage outdoors and the time spent in the morning sun.
- Begin leaving your cabbage out overnight on nights when there is no chance of a hard, killing frost.
If you would like to have some small heads to harvest, plant your seedlings 6 inches and harvest every other head. Otherwise, plant your seedlings 12 inches apart in rows that are 12-24 inches apart.
Planting Seeds Directly in the Garden
If you plan on sowing your seeds directly into the soil in your garden for early harvesting, wait until two weeks before the last frost date in your area. Space them 2 inches apart in rows that are 12-24 inches apart, and cover them with 1/2 inch of soil.
Choose a location with rich but sandy or loamy soil where your cabbage will receive full sun. Avoid muddy areas or areas where water tends to stand in puddles.
Keep the soil evenly moist, but don’t allow it to become muddy.
When your cabbage is 5 inches tall, thin it to 6-12 inches, or even 24 inches, apart, depending on how large you want your heads to be.
Sowing Cabbage Seeds for a Continuous Harvest
After your initial early spring planting, you can begin planting seeds every two weeks to ensure that you always have fresh cabbage throughout the growing season.
Sowing Seeds in a Container
If you are growing your cabbage in a container, the container should be at least 12 inches deep and 18 inches wide. Use the type of potting soil recommended above, and follow the watering instructions given above.
