Sea Kale growth stages

Sea Kale – Crambe maritima

The Best Kale Growing Site

Kale thrives in moderately rich, cool, consistently moist soil. The soil should also drain well. It is not a ‘heavy duty’, although it is best to amend the soil with aged compost and/or a well-balanced natural fertilizer before planting kale. The strongest possible kale plants will result in plenty of nitrogen, phosphorus, potassium, minerals, organic matter, and beneficial microbial activity within the soil. If you are growing kale in a container, be sure to use one that can drain freely.

Kale grows best in partial sun. Plan to provide kale plants with at least 6 to 7 hours of direct sun per day. If you’re growing kale in the spring and hot summer weather is on the horizon (regularly over 90°F), consider a planting location that receives afternoon shade. That extra protection (along with choosing the right variety) will help your kale last longer before it ‘bulges’ and goes to seed. During the increasingly dark days of fall, the more sunlight, the better! I also try to keep kale at the back (north side) of the garden beds as it can get tall quickly and shade out smaller and shorter plants.

The most important care measures

Immediately after planting, be sure to water your sea kale a few times to encourage root growth. It will not grow as abundantly as it grows on the shore of the salty beach, but it can also reach reasonable sizes as a garden plant. After the first year of growth, the roots should be established enough to provide water for the plant. Your kale will only need extra water during periods of severe drought. Nutrient requirements are moderate to high, especially if shoots or leaves are harvested repeatedly. Add a plant-based, slow-release fertilizer, such as our Plantura Tomato Food, to replenish soil nutrients in a balanced and sustainable way. You can also apply this when planting your kale.

The first shoots and leaves of sea kale can be harvested as early as April. To do this, simply cut them off with a sharp knife. In summer, the leaves will develop a distinctive kale flavor and are perfect for stews and hearty soups.

Harvest when the leaves are about the size of your palm.

Ripe kale leaves are about the size of your hand. Your kale plant will start producing leaves of this size about 70 days after planting. When the leaves are this big, your cabbage is ready and you should harvest quickly, as they will turn bitter soon after.

However, fully ripe kale leaves are not the only type of kale you can harvest. Around 25 days after planting, you will reach ‘microgreen’ size. Microgreens are basically baby kale leaves. These leaves are particularly tender and tasty (perfect for eating raw!).

Daubenton (B. oleracea var. ramosa)

Named after a French naturalist, ‘Daubenton’ is a short-lived perennial that does not go to seed – instead it is propagated by cuttings. It is a cultivated form that does not grow wild.