Does kale grow well in the summer?

QUESTION: Does kale grow well in the summer? Which kale varieties should I plant? -Shelley L

ANSWER: Kale will grow throughout the summer in USDA hardiness zones 7 through 10, but in hot weather, it tends to become tough and bitter. For best results, kale should be allowed to mature in cooler weather. That’s why gardeners should start their kale seeds six weeks before the last frost of spring in their region, so the plants have time to mature before really hot weather rolls in. If you aren’t sure of the frost dates for your area, refer to our article How to Learn Your Last Frost or Freeze Date.

If you want to grow kale in the hotter parts of summer, you’ll need to choose heat-resistant varieties that have been bred to grow healthy and strong even in the heat. A selection of some of those varieties is listed below.

• Blue Ridge: Blue Ridge is a hybrid variety of kale that has dark blue-green leaves that are fully curled, also called a “triple curl”. It resists heat well and is slow to bolt or stretch, with leaves that are easy to strip for quick preparation in cooking. This variety is ready for harvesting in about 60 days.

• Lacinato: This heirloom kale variety holds up well in hot weather. Lacinato kale grows to reach heights between two and three feet tall. It’s referred to by a slew of names, including Black Cabbage, Black Kale, Black Palm Tree, Cavolo Nero, Dinosaur Kale, Lacinato Blue, Nero Di Toscana, Tuscan, and Tuscan Black Cabbage. Lacinato kale is ready for harvesting in 60 to 80 days.

• Red Ursa: Red Ursa kale is a cross between Red Russian and Siberian kale varieties that grows between 24 and 30 inches tall. It tolerates heat well, is frost hardy, and is resistant to bolting. Red Ursa has thick, frilly oak-shaped leaves that are deep green with pretty reddish purple veins. It is ready for harvesting in 65 to 70 days.

• Squire: Squire is a variety of Vates Blue kale that tolerates heat well and is slow to bolt when overwintered. Its blue-green leaves are finely curled, and it produces high yields. Squire is a sweet, tender kale that can be chopped and eaten raw in salads or used in stir-fries, with flavor that sweetens in cold weather when frost hits. Squire kale is ready for harvesting in 60 to 70 days.

• Tronchuda/Tronchuda Beira: This Portugese kale variety has large leaves with a flat, round shape similar to collard greens. Tronchuda is resistant to both heat and cold. Its flavor is sweet and leans more toward that of cabbage than other kale varieties, and the stems are more tender than other kale types, so they can be eaten along with the leaves. Tronchuda kale grows to 12 to 18 inches tall and is ready for harvesting in about 60 days.

• Vates: This is a dwarf variety of curly kale with blue-green leaves that grows to about two feet tall. It can be planted in spring or in fall. It can be overwintered by gardeners in the mid-Atlantic region and is resistant to yellowing leaves in both hot and cold weather. Vates is also known for being an especially flavorful type of kale that’s delicious served raw or cooked. Ready for harvest in 50 to 60 days in spring or summer and 70 to 85 days fall through winter.