
University of California
UC Master Gardener Program of Sonoma County
Kale
Kale, kale, the gang’s all here…
By Rebecca Goodsell, Sonoma County Master Gardener

Because kale has been under cultivation for so very long, its origins, either the eastern Mediterranean areas or Asia Minor, are cloudy. In any case, our word “kale” is a Scottish word evolving from “coles” or “caulis”. Kale is also called borecole, which is of Dutch origin.
Kales have an interesting diversity, in that there are ornamental or flowering kales which are grown for their decorative leaves and there are the edible, or salad, kales. You can spot tall kale/short kale, curly kale or straight; blue-green, yellow-green or red; upright or flat…and all combinations thereof. The names of the varieties should give you a clue as to their outcomes…dwarf Scotch or “tall-curled”, for example. “Lacinato” is tall with beautiful, blue-green crinkly leaves. And Red Russian and Siberian kales (brassicas napus) are the most well known and widely available. The Russian-Siberian kales are typically more tender and mild flavored than the oleracea kales and can be put into a salad when the leaves are young.

Kales can be started from seed in place now for a winter harvest; or set out as starts for earlier results. The seeds are vigorous sprouters, springing from the ground at a radish-like rate. You may want to thin the seedlings, because kales are large plants and need 12” – 18” between plants, in rows 18” apart. Provide ample nitrogen in the early growth stages, as kales are heavy feeders – alfalfa hay is a great nitrogen source and does a good job of mulching, as well. Once your kale has germinated, you should be able to harvest your leaves in 65-75 days. The lower leaves can be cut as early as 30 days for use raw in a salad. As the plant matures, pick the lower leaves when they are from 5”-8” long.
Kale will wilt quickly, so pick in the morning, wash and store in the refrigerator. Kales are vulnerable to the same pests that attacked your broccoli and Brussels sprouts. These include aphids and cabbage worms/loopers. The cool weather should deter infestations, but be alert and use insecticidal soap for the aphids, or hand pick those worms that refuse to give it up for the winter. Some of you might be seed savers. Kale is a biennial, sending up their flowers or seed stalks in the spring of their second year of growth. Kale appeared regularly as a side dish on my family’s dinner table; it was, after all, Michigan in the 1950’s. I really didn’t see it in the produce markets in California at first, but now those dark leaves are there. I received a bunch in my CSA box of vegetables this very week. I readily admit to not being very much of a fan of raw vegetables, so if you want to throw in a leaf or two into your mesclun salad mix, don’t blame me if they are a bit chewy. (note: I didn’t say tough; I said chewy). For those of you in frost-prone areas, the flavor of kale is actually improved by a touch from Jack Frost.