Perennial vegetables, a sustainability game-changer for busy gardeners

Perennial vegetables

This isn’t your typical veggie patch, but keen gardeners will definitely give perennial vegetables a try. From the many species and kinds of vegetables, several can live, two, three years and more while still yielding a crop for months on end. No need to till and sow… and the crop is always ready to reap!

These hardy species grow in most temperate climates, either wedged into a flower bed or in a sunny spot of the vegetable patch. Perennial vegetables are often closer to the original wild species they were derived from. Their stronger, more affirmed taste tickles the tongues of fine dining connoîsseurs!

1- ‘Daubenton’ perennial cabbage (Brassica oleracea convar. acephala)

Daubenton kaleThis is one of the more common types of tree cabbage. Perpetual kale (or cabbage), as it’s also known, grows into a shrubby 3 to 4-foot tall shrub (1 to 1.2m). Every stem produces a small, tender head of cabbage which tastes similar to broccoli and white cabbage. Harvest as needs arise by cutting a head off. More will sprout up in its place! These young cabbage heads are delicious grated raw in a salad, and they’re also tasty when prepared like other cabbages in stews or chop-suey.

How to grow it?

Plant this Brassicaceae in full sun in a spot where the soil drains well. Add compost or very ripe manure upon planting. Topdress with the same every year to make sure yields stay on par. Propagation is very easy, simply plant offshoots to a nearby spot, that’s all! It rarely goes to seed. As an added benefit, it is highly resistant to both cabbage white and the turnip flea beetle.

2- Sea kale: soft as asparagus (Crambe maritima)

Leaves of perennial sea kaleSea kale, probably an ancestor of today’s cultivated crops, is also a perennial. It grows among the coarse rocks and sands along the coast of the English Channel and the Atlantic Ocean. Lobed leaves and white blooming in May make it a great ornamental flower bed.

In England, young stems barely blanched are much appreciated for their nutty flavor. To remove the bitterness, cover the plant in February-March with an upside-down terra cotta pot or straw. This will make the young stems grow white instead of green, and they’ll be as soft as young asparagus! The fragrant flowers are also edible, they’re an excellent addition to tossed salads.

How to grow it?

Plant the sea kale in full sun preferably, in deep soil that is dry and not too acidic. It’ll do fine in poor soil. The plant grows up to around 2 feet tall (60cm) and you should protect it from strong winds. Sow under a cold frame in March or October or propagate from roots in January. Take note that if you encounter the plant in the wild, it’s a protected species!

3- Tree onion (Allium cepa var. proliferum)

Perennial onion near a fenceIt’s called a perennial onion because you don’t need to pull the plant out to eat its bulbs. It can stay in place for years. Simply harvest the bulblets that form on the tip of flower scapes after the blooming. It has other names, too: Egyptian onion because that’s where it comes from, rocambole onion, walking onion, and also Spanish shallot as a reference to its flavor. The uncanny, top-heavy silhouette, blueish evergreen leaves and cute pink flower balls in Summer make it a fun plant to add to the garden.

The green stems grow 1½ to 3 feet tall, they advantageously replace leek or Welsh onion. You can harvest the leaves all winter long. The small onions, when mature, are delicious if you pickle them, and they’re very tasty both raw and cooked. Use them as you would other onions for a pleasant, richer flavor.

How to grow it?

In spring and in fall, plant the bulblets or sow the seeds, in rather sandy and moist soil, with full sun, or in pots to decorate your deck or balcony. Avoid manure and the like, it tends to make bulbs rot underground. Space plants 12 inches (30 cm) apart. Tree onion catawissa is a sub-variety that has a slightly blander taste, but it’s much hardier.

4- Wild leek (Allium ampeloprasum)

Perennial leekThis very interesting perennial leek indeed produces a clump of finger-thick stems that can be harvested anytime. The clump just keeps growing, year in, year out! It blooms very late in the season, and a key advantage of it is that it resists both the allium fly and cold temperatures. Ridge it twice a year to make the stems grow white underneath the soil level. It’s a tasty species of leek, with a somewhat sweetish flavor that makes it ideal for soup, omelet and quiche. Great for seasoning salad, and, if you’ve got a lot, baked in the oven.

How to grow it?

Purchase and plant small bulblets in summer, or split the leafy clumps in other seasons. 10 inches (25 cm) is a good spacing, in sun or part shade. This leek is content with loose soil, richly manured, with little watering. Harvest can begin end of August and last until the end of spring. In summer, leaves dry out because the plant goes dormant when it’s too hot.