The Old Farmer's Almanac recommends sowing kale between early spring and late summer. If planting it in the fall, cover it with straw during the winter.
Kale is very resistant to frost, so it can be planted earlier than other vegetables. It grows best in sunny conditions and tastes best if the plants grow quickly; therefore, use compost or manure to get the most flavor out of kale. Plant the seeds 1/4 to 1/2 inch deep and 8 to 12 inches apart. Kale needs regular water, but do not over-water it. Harvest the entire plant or just the leaves when they are about the size of a hand. Kale planted in the fall is sweeter when it is touched by frost.