In Hawaii, collard greens are a perennial vegetable that doesn’t go to seed. In temperate regions, they are cold-hardy, annuals. In such climates, they can often go to seed before some gardeners want them too. Sadly, our tropical climate does not have the right conditions for seed production for this Brassica. In order to keep them in good supply in the tropics, we must buy and plant seeds regularly. However, since they are perennial here, they often can grow for three years or more and you can propagate them very easily using the small growth buds from the main stalk.
Since I am a gardener and enjoy science experiments, I decided if I could propagate collards from the plant itself and not from the non-existent seeds, it would be sustainable and in agreement with my way of life. As the collard grows year after year, its stalk becomes longer and longer. If not supported it will lay on the ground. The stalk leaning on the ground will put out aerial roots that will grow into the soil. Soon after, it will produce small keiki’s or sprouts which look as if they are seedlings growing on the stalk without roots.
Take a knife (I have even pinched them off) and cut them off the stalk and put them into a pot with potting soil. I have done this with a rooting medium and without (they both seem to work fine). Remove all leaves but the most smallest and newest one. Water regularly and soon you will see them starting to grow and put out more leaves and roots. They will begin to look just like seedlings ready for transplant.
Because the plants seem to grow taller with each new leaf, often the main stalk will become susceptible to damage and may even break. If this happens, replant the stalk, removing most of the leaves and plant the stalk about 5″ in the ground and water well and it will root and recover.
Even though, this cold-hardy vegetable doesn’t go to seed, it can be propagated using these methods and grows as a perennial in Hawaii.