Start cabbage seeds indoors 4/1 at 72-85° (can use a heating mat). Days to germination: 5-8. Transplant outside 5/1, 18” apart. Or, sow cabbage seeds directly outside anytime 5/1 – 7/15. If sowing seeds outside, plant 3-4 seeds together in a group ¼ ” deep, spaced 18” between groups. Keep seeds evenly moist until germination. Thin to the strongest plant in each group. Protect cabbage plants from deer, groundhogs, and rabbits. Cabbage plants may be eaten by several different species of caterpillars. If they cause damage, hand remove caterpillars or spray organic BT.
Cabbage is ready when the head feels firm when squeezed. Cut heads flat on underside. Red Express is not ideal for long storage, but it keeps best at 32°F, with high humidity and good air circulation.
Cabbage is difficult to save seed from, so research further before attempting. Cabbage plants must be grown over two years to produce seed. Cabbage plants will need to be dug up in the fall, stored over winter, and replanted in spring. Cabbage is in the Brassica family so it is insect pollinated. Isolation distance: ½ mile. Minimum population size: 20-50 plants. To harvest seed, allow plants to flower and collect seed from mature pods.