About Late Flat Dutch Cabbage: Late Flat Dutch cabbage can be traced back to 1840, when the earliest mention of this variety is found in the seed records of the Netherlands. German immigrants carried the seed with them to America, where it spread; by 1924, it could be found in local seed catalogs such as D. M. Ferry & Company.
Late Flat Dutch Cabbage Germination: Start your seeds inside 8-12 weeks before the last spring frost, planting them in rich soil 1/2 inch deep and 2 inches apart. Because the first crop of cabbage should mature before the heat of summer, plant your seedlings about 4 weeks before the last expected frost; set them 12-18" apart in rows 3-4' apart, burying the stems about halfway up. For a fall crop, direct sow or transplant seedlings in midsummer. For companion planting benefits, plant cabbage with aromatic herbs or potatoes; avoid planting them with tomatoes or pole beans. Herbs such as thyme, peppermint, sage, and rosemary will repel the destructive white cabbage moth.
Growing Late Flat Dutch Cabbage Seeds: If hard frosts come, cover the young plants. Mulch around them to regulate soil temperature, and keep the soil moisture even to prevent the cabbages from splitting. Late Flat Dutch tolerates heat well and resists splitting.
Harvesting Late Flat Dutch Cabbage: Harvest the cabbages as soon as feel firm and reach a good size. Small cabbages tend to be more tender, while large cabbages from fall growth keep well over the winter.
Saving Late Flat Dutch Cabbage Seeds: Late in the fall, mulch at least six different cabbage plants to ensure genetic diversity. If the climate is cold, digging up the entire plant and storing it over the winter will be necessary - keep it in moist sand at a temperature of about 40 degrees F. Replant 4-6 weeks before the last spring frost. If the heads are still firm, cut a deep X in the top to provide an easier exit for the stem. The stem will grow about 4-5' tall, with many four petaled yellow flowers. Allow the flowers to mature; when the seed pods form, pick them and allow them to dry. Remove them from the pods and store them in a dry, cool place for up to five years.
Detailed Late Flat Dutch Cabbage Info: Brassica oleracea var. capitata. Biennial. 100 days. 7000 seeds per oz.18-24" height. 24-30" spacing. Produces 10-12 lb. oval heads.