Red cabbage is a cool weather crop that can be planted early in the season. Though it resembles purple more than red look for seeds labeled as red cabbage.
Ph Plays a Role
The colour of the plant can in part be determined by the ph level in the soil. In soil that is more acidic the plants will be more red. In soil where the ph is more neutral the colour will be more purple.
Starting Red Cabbage from Seed
Get an early start on the growing season to assure a successful harvest. You can start seeds 3 – 4 weeks before the last frost. All you need is potting soil, a few containers and a sunny window.
Potting soil can be purchased at most hardware stores that have garden centers. Make sure all planting containers have drainage holes before starting. Using planting cells (6 or 9 packs) or any small container, plant one seed per cell at a depth of 1/4 inch. Cover the seeds with soil.
Lightly water the planting cells and place the tray in a warm location with the cover on. Heat and moisture help speed up germination of seeds so be sure to keep the soil lightly damp. Seeds should germinate between 7 – 14 days. Once the seeds have sprouted remove the lid and place the tray in a sunny spot or under lights. Monitor the seedlings making sure the soil does not dry out.
Hardening off Cabbage
Any plants that are started indoors need to be hardened off before being planted outdoors. Two weeks before you plan to move the plants into the garden you can begin the hardening off process.
Place the plants outdoors in a sunny, wind protected area during the warmest part of the day for a few hours. Everyday extend the amount of time the plants spend outdoors. After two weeks the plants can be moved into the garden. The plants should be around 4 inches tall and have 4 – 5 leaves.
Planting Red Cabbage in the Garden
Select a location that receives at least 6 – 8 hours a day. In hot growing locations some shade is acceptable during the day. Seeds and transplants can be planted once the soil can be worked. You can also grow cabbage in raised beds and containers.
Work the soil well adding amendments like peat moss and compost. If the soil is compact, the addition of sand helps loosen the soil and aides with drainage. Make sure any containers have adequate drainage holes.
Space the rows 18 to 24 inches apart. If planting seed directly into the garden space the seeds 12 -18 inches apart and the seeds at a depth of ½ inch. Once the seeds have germinated thin the plants to 18 inches apart.
If you are transplanting seedlings, space them 16 – 24 inches apart throughout the rows. This is a good time to add mulch to the garden. Mulching the rows helps maintain moisture in the soil and substantially restricts weed growth.
For containers it is best to transplant red cabbage seedlings. Plant one seedling per container and water well. Set the containers in the sunniest part of your yard or garden.
Caring For Red Cabbage
Cabbage attracts many bugs. Row covers can be placed over the plants early in the season. This helps in protecting the young plants. As the plants grow hand pick any unwanted pests from the plants.
Onions, dill, radishes, thyme, sage and nasturtiums are good options for companion planting with cabbage to help repel bugs.
Cabbage performs best when it has consistent even watering, especially important for container grown cabbage. Overwatering can cause the heads to split and the plants will perform poorly.
Cabbage is a heavy feeder and does well when compost is added during the growing season. If you do not use compost in your garden an all-purpose fertilizer like a 20-20-20 can be used. Be sure to follow the mixing and watering instructions on the container.
Avoid planting cabbage near strawberries, tomatoes, cauliflower and broccoli.
Implement Crop Rotation in your Garden
It is important to practice crop rotation when growing cabbage using a 4-year cycle. This prevents the soil from becoming nutrient deficient from repeated plantings in the same location. Because different plants have different nutrient needs moving the planting location every year is important. It helps maintain healthy soil and some plants add nutrients back to the soil. It also reduces soilborne diseases from occurring.
We can take advantage of the plant placement to add back to the soil with an easy system of rotating where we place plants from year to year. The easiest way to plan your rotation is to group plants that belong to the same family together into 4 groups.
The first is legumes, this includes peas, lima beans, beans & edamame. The second grouping is root, this includes onions, turnips, carrots, garlic, beets and radishes. The next group is leaf which contains lettuce, greens like kale and spinach, herbs, cabbage, broccoli and cauliflower. The final grouping is fruits, included in this group is cucumbers, tomatoes, squash, eggplant, peppers, melons and potatoes.
The diagram below breaks it down into easy to do steps.
The top row is year one. The second row is year 2 and shows where each group is planted in the second year. Row three again is year 3 and shows where each group is planted in the third year. The fourth row is where each group is planted in its fourth year.
At year 5 you begin the rotation again.
Harvesting Cabbage
Depending on the variety cabbage can be ready for harvest is as early as 80 days from seed. Harvest cabbage when the heads are nice, tight and firm.
Using a sharp knife cut the cabbage at the base of the head. Or you can pull the entire plant from the garden. Remove the head of cabbage and put the roots and remaining leaves into the compost pile.
Storing Cabbage
Store plastic wrapped heads in the fridge for 2 – 3 weeks. If you have a good cold storage area, heads will remain fresh for up to 3 months.