Kohlrabi

Family: Brassicaceae, alternatively known as Cruciferae (Mustard family)
Genus: Brassica
Species: oleracea

This article is dedicated with deep affection to John Van Miert, whose column in this newsletter predates mine by more than a dozen growing seasons. John, the most knowledgeable gardener I know, has retired from his column-writing responsibilities, but he will continue in his gracious manner to share his knowledge and experience with us all, so that our own flower gardens can be more beautiful and our vegetable gardens, more bountiful. He also shares the fruits of his garden, and one of them is the featured plant for this month.

As I write this, my son is excited about dinner tonight. No, the pizza delivery person isn’t coming to call. We’re having kohlrabi, fresh from John Van Miert’s garden, and it’s one of Leon’s favorite things to eat. If this healthy treat, rich in vitamin C and potassium but low in calories, can tempt a 15-year-old, it will appeal to just about anyone. Its name is a combination of Kohl, the German word for “cabbage,” and rapa, the species name for the turnip, but it is not a cross between the two, botanically speaking. All three, however, are members of the same very large and important Brassicaceae plant family—the Mustards, also known as the Cruciferae family. That latter name, by the way, derives from the fact that the flowers of family members have four petals, arranged in the shape of a cross. The serious plant namers who assemble the International Code of Plant Nomenclature have permitted this family to retain both names, a rare occurrence indeed in the annals of plant identification. These crucifers are also distinguished by the presence of chemical compounds called glucosinolates. These are responsible for the pungency that’s characteristic of many family members. But the family extends beyond edibles like mustard, broccoli, cabbage, and cauliflower. It includes ornamentals such as perennial and annual alyssum, stock, candytuft, and wallflower. And in the good-news, bad-news department so common with plants, it also counts among its members some of our most common and troublesome weeds: Capsella bursa-pastoris, or shepherd’s purse; and Cardamine hirsute, that annoying hairy bittercress that pops up here in the early spring and flings its seeds everywhere if we turn our backs on it for even a day.

Kohlrabi is a biennial, which means that if you grew it for its flowers, you’d have to wait to see them until the year after you put in your seeds. But its flowers are not what this plant brings to our tables. The part we eat is the bulbous stem, enlarged at the level of the soil. The leaves grow out and up from it in a most amusing manner. In fact, if any of our readers are fans of Ruth Plumly Thompson, the successor to L. Frank Baum as the Royal Historian of Oz, they will already know that she and illustrator Jno. R. Neill used kohlrabi as their inspiration for the unpleasant Mugly and the other Headmen of Headland. Perhaps this was a statement about kohlrabi’s taste, which has gotten what some of us feel is a very bad rap. Choose the correct seed, don’t let the plants dry out, and pick them while they’re about the size of a baseball, and you’ll have a vegetable that is crisp and sweet and a genuine pleasure to eat.

All crucifers grown for table use are cool-season vegetables, so plant your kohlrabi seed in the very early spring and again in late summer for a possible fall harvest. While they are known in other parts of the country as quick to mature—in about 55 days—add half as many days for harvest here in the Pacific Northwest. They do admirably well in our climate. They are also relatively pest-free—even slugs have a difficult time gnawing through the tough outer layer of the stem—and not prone to any particular disease. Another plus is that they’ll lend a note of whimsy to your garden.

There are a number of vegetables that are best when they’ve been grown in a home garden or at least by a local grower. Their taste and texture deteriorate when they’ve spent time on the road. Kohlrabi is certainly one of these, but it is a commercial crop in some areas of the country. There’s even a town in California that’s named after it and yes, they host a Kohlrabi Festival every year. That degree of allegiance is perhaps a bit much to ask. But if you’re looking for an interesting side dish for your Thanksgiving table, you might want to at least give it a try. Who knows, perhaps next year you’ll be planting some white ‘Triumph’ or some purple ‘Kolibri’ in your own garden. Leon and I think you’ll be glad you did.

Happy Thanksgiving, everyone.