Kale is a leafy green vegetable that contains a high level of minerals in its rich, juicy leaves. While able to grow all year long, kale is best suited to the cooler months of the year when its leaves taste sweeter and are more succulent. Transplant each seedling into a hole that has been amended with at least 3 cups of compost, one cup of landscape mix and one cup of worm castings. Pick the leaves from the bottom, up and you will have a prolonged harvest. Kales will typically produce new leaves for one year and then they will put their energy into blooming, at which point they can be removed from the garden.