Germination: 7 to 14 days Full Sun.
Cabbage is a heavy feeder and grows best in fertile soils rich in organic matter. Plant in well-drained soil containing a pH between 6.5-7.5.
Starting Indoors: Sow in flats or modules from February until early April at a seed depth of 6mm (¼”). Cover lightly and firm. Once plants have at least two true leaves, transplant into individual pots. Harden off gradually in April or early May for transplanting outdoors.
Direct Seed: For a later crop, direct seed outdoors from early March until the first week in June. Thin the seedlings as soon as they appear. Keep moist. Space rows 91cm (3’) apart and plants 46–61cm (18-24”) apart.
Maintenance
Water well and often. Mulching will help with water retention, weed suppression, and can help guard against the cabbage fly.
Cabbages and other brassicas love their nitrogen. I’ve found it useful to prepare the ground with manure before planting and then work in some blood or fishmeal later in the growing season. I also like to add some chicken pellets in May (just keep them away from the base of the plant).
Here in the UK, the wood pigeons love, love, LOVE to eat our brassicas. Make sure you net your plants or you’ll find they beat you to the crop. (Netting also helps protect against the cabbage butterfly.)
Harvesting
Harvest June-October, when the heads are firm all the way through when squeezed. To avoid splitting, harvest heads as soon as they are ready. Cut the stalk at the lowest point possible, leaving the loose, outer leaves attached to the stalk. (This will allow for a later harvest of sprouts.)
Companion Planting
Cabbages grow well with other brassicas (i.e. broccoli, kale, and brussels sprouts). It also likes tomatoes, spinach, and swiss chard. It benefits from being planted with alliums (onions and garlic).