Water your plants often. Dry periods won’t necessarily harm the plant, but the leaves will take on a much stronger flavor afterwards and possibly become too bitter to eat.
Collards do grow larger than most other greens, so you will have to have one plant per 10″ pot. Larger containers are fine with 2 plants as long as you can provide at least 18 to 20 inches between their main stalks. Keep them well-watered and well-fed with fertilizer.
You can start taking leaves about 4 to 6 weeks after you’ve started your seeds. If you let the leaves get too large before cutting, there may be a tough central stalk through the leave that will have to be cut out before using.
For spring collards, your growing season comes to an end when hot weather arrives and your plants bolt to seed. The leaves will be too bitter to eat at this point. It’s not a problem with fall collards, and you can keep on harvesting well after the frosts start arriving.
Cooked collard greens can be frozen for longer storage, but the fresh leaves will only last a few days in the fridge.
Germination temperature: 50 to 80 degrees. Will germinate at soil temperatures as low as 45 F. Maintenance and care: Direct seed about three months before expected fall frost. Plant seeds ¼ to ½ inch deep, 1 inch apart in rows 18 to 30 inches apart.