By Charlotte Glen, Horticulture Agent, NC Cooperative Extension
NORTH CAROLINA — Kale is easy to grow, productive, versatile and an antioxidant rich super food. Whether growing kale to harvest baby leaves for salads or to harvest mature leaves for soups and sautéing, now is the time to get started.
When most people think of kale, they picture plants with curly edged, blue-green leaves. These standard types, which include Winterbor and Dwarf Blue Curled Vates, are the most cold hardy varieties, capable of surviving outside without protection all winter. They are also the types most often found for sale at garden centers as young plants to set out in a garden in September. However, there are other varieties.
Red Russian kale, an heirloom variety with purple stems, is another variety. The blue-green leaves of Red Russian kale are smoother than other types, with deeply toothed edges and an extra tender texture. The plants tolerate light to moderate frost, but young leaves can be burned when temperatures fall below the mid twenties. Cover plants with frost protection cloth or a blanket to prevent frost burning.
Toscano is another heirloom kale that thrives in fall and winter gardens. Coming from Italy, this variety is also known as lacinato, Tuscan or dinosaur kale. Bearing deeply wrinkled, blue leaves with smooth edges, Toscano kale is a favorite to many. Cover these plants whenever temperatures dip below the mid 20s.
Though it’s not a type of kale, Spigarello is similar. Sometimes referred to as leaf broccoli, this plant can be grown the same as kale. After three to four months, the plant will produce small edible broccoli heads, similar to broccoli raab.
There are two methods of growing kale depending on how the leaves will be used. Young baby leaves can be used for salads or juicing. Baby kale can be grown year-round, but it will have a different taste in the off season.
Baby kale can be grown in the garden or in containers of potting soil. Sow seeds every half inch in shallow furrows, spaced three to four inches apart, or scatter them across the bed or container and cover them lightly with soil. Check the soil every day to make sure the seed bed is kept moist, but there is no need to fertilize until the plants come up. Kale started in the summer months will greatly benefit from afternoon shade.
To grow kale plants for a winter garden, sow seed in early to mid August. When seedlings reach two to three inches in height, transplant them into small containers of potting soil. Set young plants out in the garden in early September and begin harvesting leaves after the first frost.