Usually around this time, the middle of winter, I start craving movement and bright green things. The world around me is growing slowly greener by the second. Everything is just starting to wake up as the days get warmer and longer. It also happens to finally be time to start planting seeds for this year's garden. Some of the first seeds I reach for are my brassica seeds.
Brassicas! What a varied and incredible group of vegetables. Collards, cabbage, kohlrabi, broccoli, cauliflower, romanesco and kale are just some of the many vegetables that share the same species name Brassica oleracea. It might surprise you, as it did me that all of these plants that look so different are just varieties of the same species.They have been selected for various traits, whether it be the thick stem of the kohlrabi, tightly packed head of cabbage or the magical spiral of romanesco. They have common wild relatives and their cultivation dates back to at least the Bronze age or around 2000 BC. The original relative of these delightful garden staples is not agreed upon in the scientific world.
Each brassica that we eat was bred by people to add diversity to our diets. Because of that they are one of the most significant species of vegetables to humans today and continue to be grown around the world from China to Africa to North America.
Today we are going to talk about kale. Mostly because I love it but also it is super easy to incorporate into your diet and I find myself craving it nearly daily right now. Kale is extremely nutritious. You might have seen the claims that it is a superfood. It has protein, fiber, vitamin c, beta-carotenes, calcium, magnesium and potassium. Just to name a few of the reasons this food is on the top of my spring eating and planting list.
Right now I am adding it to my eggs in the morning. Lightly sauteed with olive oil and garlic then added into scrambled eggs. Other ways to incorporate kale are in smoothies, salads and soups. I find it to be an excellent side dish prepared similarly to spinach as well. In Zimbabwe it is prepared as a relish that is eaten with stews. They also blanch the leaves in salted water and then dry them in the sun to eat during the dry season. Preserving kale is not as necessary in North America as mature plants usually make it through the winter, especially in Oregon. However, kale chips are pretty delicious if you find yourself wanting a nutritious alternative to potato chips.
Kale maintains more of its nutrients if it is eaten raw, wilted or blanched. So keep that in mind when you are cooking it. I try to maintain the original color of green that the raw leaf has in cooking. There are lots of different leaf forms of kale and each has a slightly different texture and flavor.
Favorite Varieties of Kale
Alive Vates Grex- This is a Siskiyou Seeds original bred from six different types of kale, Winterbor (F1), Starbor(F1), Easy Pick (F1), Darkibor (F1), Dwarf Blue, Scotch curled, Meadowlark, Nash's Green. It is super curly with blue green leaves. The seed was selected from the hardiest plants, making it an excellent choice for fall gardens and over wintering. Overwintering kale leads to very sweet leaves just like overwintered carrots yield the sweetest carrots. This is a great variety for kale chips and salads.
Black Tuscan- Also known as dino kale, Italian kale or lacinato kale, this type has dark almost blackish green leaves that are flat and tender. Black Tuscan is in the Acephela group of brassicas, which is the non-head forming variety. This variety is both cold and heat tolerant. It has been cultivated in Italy for hundreds of years. I prefer the texture and taste of Black Tuscan kale over other kale varieties. It is excellent when added to soups or pastas and is my preferred variety to add to egg dishes.
White Russian- Definitely the most cold hardy type of kale to grow and the best choice for fall gardening. It has a different species name from the last two varieties and is a Brassica napus. It was developed by Frank Morton from Siberian kale crossed with ‘Red Russian’ kale. This variety has a much more mild and sweet flavor. It is a good gateway kale if you are not sure if you are ready for the other types which are slightly more bitter and fibrous. This is my favorite variety to grow as a baby leaf and add to salad mix or mesclun mix.
How to Grow Kale
There are two different ways to grow kale. Similar to lettuce you can either grow large individual kale plants or direct seed kale for cutting like salad mix.
To grow large plants: Prepare trays of potting soil and then place one to two seeds in each individual cell. Gently cover with soil and tamp down. Water the trays daily but allow for the top of the soil to dry slightly between waterings to keep fungal issues down. Kale germinates best between 50-80 degrees and should come up within 7-10 days. Kale is fairly hardy for optimum speed and germination rate aim for around 65 degrees. Sow kale about 6-8 weeks before your last spring frost. Then transplant the seedlings after the first true leaves have formed or when they are around 4 inches tall. Kale should be spaced at about 18”. It will grow closer together but if your goal is a few big juice kale plants give them some room to spread out. Harvest kale leaves from the bottom to the top. Pull the leaf in a downward motion off of the stalk. It should come off fairly easily. Move around the stalk pulling the largest leaves off gently. Make sure you always leave a few leaves at the top of the plant. Do not harvest the smallest center leaves at the very top of the plant. These leaves will continue to grow. You can usually harvest from each plant every week. I think about 4-6 kale plants is a great number for a small garden that 2-4 people are eating from.
To grow for cutting: baby kale beds should be planted about 2 weeks before the last spring frost. Prepare your garden bed by incorporating compost into the soil and then raking flat. Use a hand spade to draw trenches that are about ¼ inch deep and 4-6 inches apart. Place kale seeds every inch inside the trench. Gently pull the soil down from the sides of the trench to cover your kale seeds. Tamp the soil down over the seeds. Make sure to mark the rows that you planted and to water regularly. When the small kale plants are about 4-6 inches high you can cut them for your baby kale mix. Use sharp scissors and cut the tops of the leaves off as you would harvest salad mix. Make sure you cut too far down on the plant. Cut just above the smallest center leaf so that the plant can re-grow. You can also thin the baby kale plants instead. Thin every other plant in succession until your plants are spaced about 16” apart and then leave those plants to grow into big ones!
Kale can be grown in the spring and fall. It generally declines in vigor and taste in the hottest summer months. Plant kale in late winter and in July for multiple excellent harvests.
Chengcheng Cai, Johan Bucher, Freek T Bakker, Guusje Bonnema, Evidence for two domestication lineages supporting a middle-eastern origin for Brassica oleracea crops from diversified kale populations, Horticulture Research, Volume 9, 2022, uhac033, https://doi.org/10.1093/hr/uhac033
Mabry ME, Turner-Hissong SD, Gallagher EY, McAlvay AC, An H, Edger PP, Moore JD, Pink DAC, Teakle GR, Stevens CJ, Barker G, Labate J, Fuller DQ, Allaby RG, Beissinger T, Decker JE, Gore MA, Pires JC. The Evolutionary History of Wild, Domesticated, and Feral Brassica oleracea (Brassicaceae). Mol Biol Evol. 2021 Sep 27;38(10):4419-4434. doi: 10.1093/molbev/msab183. PMID: 34157722; PMCID: PMC8476135.
Mariga, I. K., Mativha, L., & Maposa, D. (2012). Nutritional assessment of a traditional local vegetable (Brassica oleracea var. acephala). Journal of Medicinal Plants Research, 6(5), 784-789.
Rodríguez, V.M., Soengas, P., Alonso-Villaverde, V. et al. Effect of temperature stress on the early vegetative development of Brassica oleracea L.. BMC Plant Biol 15, 145 (2015). https://doi.org/10.1186/s12870-015-0535-0