Crambe maritima

We have long admired the European beach native Crambe maritima, but repeatedly failed when trying to grow it, assuming it to have no tolerance of our summer heat and humidity. We failed, until we stopped being too nice and planted it in almost pure gravel in our full sun crevice garden, where it has thrived. Being a halophytic (loves salty soils) coastal native, deep sandy soils will also provide a proper habitat. Crambe maritima (first cousin to cabbage) is grown both as an ornamental and a food crop. The thick, waxy, heavily ruffled, large blue leaves of this RHS Award of Garden Merit winner are reason enough to grow sea kale, but when it sends up the tall spikes of baby's breath-like white flowers in spring, your heart will just melt.

Maintenance:

Crambe maritima requires virtually no maintenance in the garden. For us, it goes tardily deciduous in winter, so you can remove the old foliage to keep the garden tidy. The beauty of sea kale is that we don't see any damage from cabbage loopers or any of the common pest that are prevalent on other related crops like cabbage.

Once the flowers of sea kale finish in spring, the old stalks can be removed unless you need to leave them to gather seed before cutting them back. Sea kale can be divided easily, but since the base can be extensive, it's best to dig the entire clump, separate it, then replant the divisions. It also grows from root cuttings, so if you move your plant, expect new ones to sprout in the old location.

We pick sea kale throughout the growing season for a raw garden snack, or to cook for a meal.

Growing Conditions:

We can't stress enough that bright light, and dry, well-drained soils are the key to success. While Crambe maritima doesn't need extra irrigation, it certainly doesn't mind getting watered as long as the soil doesn't get saturated.

Natural Impacts:

Bees are the primary pollinators of sea kale that we've observed, along with a few smaller species of flies