How to Grow Kale From Seed
I may not be holding true to my southern roots to admit it, but I greatly prefer kale to collards. In fact, kale is my favorite cool season vegetable. And what’s not to love? Kale is easy to grow, productive, versatile, and an antioxidant rich super food. Whether you want to grow kale to harvest baby leaves for salads or to harvest mature leaves for soups and sautéing, now is the time to get started if you plan to grow kale from seed for your fall garden.
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 through early winter. They are also the types most often found for sale at garden centers.
While I think every fall garden should include some of these extra hardy types, there are other varieties of kale that are tastier and tenderer. One of my favorite is ‘Red Russian’, an heirloom variety with purple stems. The blue-green leaves of ‘Red Russian’ kale are smoother than other types, with lacey, toothed edges and an extra tender texture. The plants tolerate light to moderate frost but young leaves can be damaged when temperatures fall below the mid-twenties. You can cover plants with frost protection cloth to prevent damage and or grow them in unheated tunnels or cold frames to keep plants producing longer into the winter.
‘Toscano’ is another excellent heirloom kale that thrives in fall gardens. Coming to us from Italy, this variety is also known as lacinato, Tuscan, or dinosaur kale and bears deeply wrinkled, blue leaves with smooth edges. ‘Toscano’ kale is my absolute favorite for flavor and texture. It is the least hardy of the kales I have grown and is damaged by cold more often than ‘Red Russian’. I cover these plants whenever temperatures dip below the mid twenties.
Though it’s not a type of kale, I highly recommend Spigarello to kale lovers. Sometimes referred to as leaf broccoli, this plant can be grown the same as kale, though you will likely have to start it from seed as I have never seen plants for sale at garden centers. I harvest and cook the leaves of Spigarello, which have a sweeter, more broccoli-like flavor, the same as I do kale. After three to four months, the plant will produce small edible and delicious flower heads, similar to broccoli raab.
There are two methods of growing kale depending on how you plan to use the leaves. If you want young baby leaves for salads or juicing you will need to sow a new batch of seed every two to four weeks and harvest when the plants reach four to six inches tall. You can grow kale for baby leaves all year round, but you will notice a distinct difference in the taste of plants grown in warm weather versus those grown in cool weather. This is because frost changes the flavor of kale by increasing the sugar content of the leaves, making their flavor sweeter and richer.
Baby kale can be grown outdoors in the garden or in containers filled with potting soil. If you are sowing seed directly in the garden, first cultivate the soil and rake it smooth to create a level, finely tilled seed bed. You may or may not need to add lime and nutrients to your soil depending on how much was added in the spring. If you have not had your soil tested in the last few years pick up soil test boxes and forms from your local Extension office. Fill the boxes with soil from your garden and mail them to the NC Department of Agriculture & Consumer Service’s soil testing lab in Raleigh (the address is on the box). Samples are currently taking around 1 week to process. Your results will be posted online and will tell which nutrients you need to add to your soil for optimal plant growth. Learn more about soil testing from NCDA&CS.
Kale plants cultivated for baby leaves are grown much closer together than plants that are allowed to grow to full size. When seeding kale for baby leaves, you can either carefully sow seed every half inch in shallow furrows spaced three to four inches apart, or simply scatter them across the bed and cover lightly with soil. Being an impatient gardener, I usually opt for the latter method. Check the soil every day to make sure the top 3”-4” of the seed bed is moist but not soggy. If the soil is dry, water gently with a watering can or run lines of soaker hoses or drip tape across the bed to apply water slowly at ground level.
To grow kale plants for your winter garden, you can either start seed in late July – early August to grow your own transplants or buy transplants from a local garden center in September. To grow your own transplants, sow seed in shallow containers filled with seed starting mix (this is usually a mixture of peat moss, vermiculite, and perlite). The containers can be kept outside in a sunny area but will likely need to be watered daily. At this time of year, seedlings usually germinate within 3-5 days of sowing. When they start to develop true leaves (typically 10-14 days after sowing), transplant individual seedlings into cell packs or small pots filled with potting soil and begin watering them with a weak solution of liquid fertilizer or fish emulsion. Allow plants to grow on for three to four weeks before transplanting to the garden in early-mid September. Space young plants 2’ apart in the garden and begin harvesting leaves after the first frost.
Other fall vegetable crops you can sow now to grow your own transplants include cabbage, collards, Brussels sprouts, broccoli, and cauliflower. Learn more about vegetables you can plant in the fall from this NC State Extension factsheet.
Want to know the best time to plant many different types of vegetables and herbs? Check out the Vegetable Planting Calendar for the NC Piedmont
Looking for detailed information on how to grow individual vegetables, including recommended varieties, common pests, and fertilization needs. Check out the vegetable fact sheets from Clemson Extension.
Can’t find the seed you seek at your local garden center? Lots of seed companies offer free catalogs and take orders online. Here are some that offer a wide range of vegetable seed:
- Johnny’s Seed: Flowers, vegetables, herbs, cover crops and excellent information!
- Burpee Seed – one of the oldest in the country!
- Park Seed – located in Greenville, SC:
- Seed Savers Exchange – dedicated to preserving heirloom varieties
- Seeds of Change – specializing in organically produced seed:
- J.L. Hudson – No color pictures but lots of interesting varieties – carries only open pollinated varieties (which means you can save your own seed and they will come true):
Use Extension Search to find research based information from Cooperative Extension systems across the U.S.
Subscribe to the Chatham Gardener email list to receive gardening updates for Chatham County and the central North Carolina Piedmont