Planting Guide and Seed Saving Notes for Kale

Kale (Brassica spp.)

Very cold hardy. It seems a garden without kale is incomplete. With so many varieties, colors, textures and flavors there is surely one to suit any taste. Some of them are so colorful and beautiful that they can even be used as an ornamental. Extremely nutritious, kale can be eaten fresh in salads or cooked in any number of ways, limited only by one's imagination.

Nutrients: dietary fiber, vitamins A, C (very high) and E, calcium, potassium, iron, folate, beta-carotene and the phytochemical quercitinbeta-carotene.

How to Grow Kale from Seed

Bed Preparation

The Brassica family grows best in well-drained soils with compost and available nutrients like Nitrogen. Add compost to ensure that the seedlings will have food immediately available to them once planted in the ground. Kale grows best in partial shade/part sun.


Seed indoors Plant seeds in trays for spring and fall planting. Use Seedling soil or potting soil that acts as a simple substrate. Plant seeds in holes at a depth of ½” planting 3-4 seeds in each hole about 1” apart. Cover the seeds with soil and lightly pat soil to cover each hole. Place tray under grow lights or near a south-facing window. Give seedling tray one good “soak” of water after planting and every day to ensure that the soil stays moist.

Once you have located the best spot for planting, plant each seedling 12” apart. When removing the seedlings from your seedling tray, lightly pull each one out of wet soil and loosen the roots from the soil as much as possible without damaging the roots. Use your finger to punch a hole in the soil deep enough to fit all of the seedling’s roots into the hole. Until harvest, continue watering once a day in the evening. Apply an organic fertilizer every two weeks to push the plants along in production and keep them healthy.

For direct sow, seeds will take approximately 3-12 days to sprout. As the seedlings appear and grow, weed out the smallest sprouts leaving only the largest and strongest in the tray. You will need to “harden off” the seedlings started indoors before planting them outside in a container or garden bed.


Kale is typically ready to harvest after 50 days. Some varieties, such as Portuguese Kale, may take as long as 85 days to mature for harvest. Just keep an eye on your plants, mentally noting their progress. Once the leaves reach desired size, or about the size of kale leaves you see in the grocery store, clip them off the plant using a pair pruning shears or scissors. Do not cut all the leaves to have a “cut and come again harvest”. This way you can reap the bounty of a healthy Kale harvest all summer long! Happy planting.

How to Save Kale Seed

Kale needs to undergo exposure to winter cold in order to flower and set seed, so in milder climates, fall planting for seed harvest the following summer works great. In very cold climates it might be necessary to dig the plant up, trim the leaves and store in sawdust or sad for planting out in spring after frosts have passed. Mediterranean kales of the Brassica oleracea species will cross with each other as will the Siberian kales, Brassica napus, but the Mediterranean and Siberian varieties will not cross with each other. For good seed genetics, allow several plants of the same variety to flower at the same time. Harvest seed pods when brown and dry.