Growing Perennial Vegetables: Plant Once, Harvest for Years

I ripped out my entire front lawn six years ago, and the single best decision I made was planting perennial vegetables first. While my neighbors were replanting tomatoes every spring, I was harvesting asparagus spears in April, rhubarb stalks in May, and sunchoke tubers in November — all from plants I put in the ground once. Perennial vegetables are the closest thing to a permanent food system in a temperate climate, and most gardeners overlook them entirely. The average annual vegetable garden requires 40 to 60 hours of bed prep, planting, and replanting per season. A well-established perennial bed drops that to under 10 hours of maintenance per year after the second season, while producing 15 to 25 pounds of food per 100 square feet. This is not theory. I have measured this in my own USDA zone 6b garden in the Hudson Valley, where I now grow 20 perennial food species on a quarter-acre lot. Here are the 15 plants that earn their keep with minimal fuss, along with exact cultivars, spacing, and the mistakes I made so you do not have to.

Asparagus, Rhubarb, and Horseradish: The Three Pillars of the Perennial Garden

Asparagus is the slowest payoff in the perennial world and the most rewarding. I planted 25 crowns of ‘Jersey Knight’ in a 4-foot-wide by 20-foot-long raised bed in April 2019. ‘Jersey Knight’ is an all-male hybrid that produces thicker spears and yields about 30 percent more than heirloom varieties like ‘Mary Washington’, which waste energy on seed production. I spaced the crowns 18 inches apart in trenches 8 inches deep, then backfilled gradually as the ferns grew. The first year, I harvested nothing — you must let the ferns grow and die back to build root mass. Year two, I harvested for two weeks. Year three, six weeks. By year four, I was cutting 1.5 pounds of spears per plant per season, totaling roughly 38 pounds from that single bed. The most common failure is planting in poorly drained soil. Asparagus crowns rot in standing water within 72 hours. I lost six crowns my first year to a low spot that held spring rain. If your soil is heavy clay, build a raised bed at least 12 inches tall and mix in 3 inches of compost before planting.

Rhubarb gets treated like a fruit but is botanically a vegetable, and it is nearly impossible to kill. I grow ‘Victoria’, an heirloom that produces thick, green stalks with just enough red blush to look pretty on the plate. I planted three crowns 3 feet apart in October, and by the second spring each crown was producing 4 to 5 pounds of stalks over an 8-week harvest window. Do not harvest any stalks the first year — the plant needs that foliage to photosynthesize and build root reserves. The mistake I see constantly is people cutting stalks instead of pulling them. You must grasp the stalk near the base and pull it sideways to detach it cleanly from the crown. Cutting leaves a stub that rots and can introduce disease. Rhubarb thrives in zones 3 through 8, but in zones 7 and 8 it needs afternoon shade or the stalks go limp and stringy by June. I lost a planting to crown rot in zone 6b when I mulched too heavily with wood chips directly against the crowns. Keep mulch 4 inches away from the crown center.

Horseradish is the thug of the perennial bed, and you need to contain it or it will take over. I planted one crown of ‘Maliner Kren’, a Bohemian variety with exceptional heat, in a 5-gallon bucket with the bottom cut out and sunk into the ground. That single plant produces 3 to 4 pounds of roots per year, which is more than my family of four uses in a year of sauces and ferments. The roots grow 12 to 18 inches deep and spread aggressively via lateral roots. If you break off a piece of root during harvest and leave it in the soil, it becomes a new plant. I learned this the hard way when I dug up the original planting carelessly and ended up with horseradish popping up in a 6-foot radius the following spring. Harvest after the first hard frost in fall — cold converts the root starches into sugars and intensifies the pungency. Dig the main root, save a 6-inch piece for replanting, and you are set for next year.

Sunchokes and the Underground Bounty That Keeps Giving

Jerusalem artichokes, properly called sunchokes, are the highest-yielding perennial vegetable I grow, and they require zero care after planting. I put in 1 pound of ‘Stampede’ tubers in a 4-foot by 8-foot bed in April 2020, spacing them 12 inches apart and 4 inches deep. ‘Stampede’ is an early-maturing variety that produces uniform, knobby tubers and tops out at 6 feet tall, unlike the 10-foot monsters of older varieties like ‘Red Fuseau’ which fall over in the first windstorm. By November of that first year, I dug up 18 pounds of tubers. By year three, that bed was producing 35 to 40 pounds annually. The plants spread aggressively through underground rhizomes, and if you do not harvest every single tuber, you will have sunchokes forever. Some people consider this a feature. I consider it a warning. Plant them in a contained bed with buried edging, or accept that they will naturalize. I have sunchokes growing in my lawn now from tubers I missed three years ago.

The one problem with sunchokes is the inulin. These tubers store carbohydrates as inulin rather than starch, and for many people, inulin causes significant digestive gas and bloating. I learned this after serving a sunchoke gratin at a dinner party and spending the next 12 hours regretting every bite. The fix is simple: ferment them or cook them with an acid. I lacto-ferment sliced sunchokes in a 2 percent brine for 10 days, which breaks down the inulin into digestible short-chain fatty acids. Roasting them with lemon juice or vinegar for 45 minutes at 400°F also helps. The ‘Red Fuseau’ variety is slightly lower in inulin than ‘Stampede’, but the yield is about 20 percent lower. For a family with sensitive digestion, I recommend starting with ‘Red Fuseau’ and fermenting half the harvest.

Ostrich fern fiddleheads are the wildcard in this category, and they are the only perennial vegetable I grow that I did not plant intentionally. I transplanted three ostrich fern crowns (Matteuccia struthiopteris) from a friend’s overgrown patch into a moist, shaded corner of my yard in early spring. They spread via underground runners and now cover a 10-foot by 6-foot area. The fiddleheads emerge in early April in zone 6b, and I harvest about 2 pounds total over a 10-day window — you must pick them when they are 2 to 4 inches tall, still tightly curled, before they unfurl. Once they open, they become bitter and fibrous. The window is short, and I missed it entirely my first year because I was distracted by asparagus. Ostrich ferns are hardy in zones 3 through 7 and require consistent moisture. If your soil dries out in summer, the fronds brown and the plants stop spreading. Mine are planted under a downspout, which provides all the water they need.

The Onion Family That Regrows Itself Every Year

Egyptian walking onions are the most entertaining vegetable in my garden, and they are practically immortal. I started with five bulbs from a neighbor in fall 2019, planted them 6 inches apart and 2 inches deep in a 3-foot by 3-foot bed. By the second summer, each stalk produced a cluster of 8 to 12 small bulblets at the top, which then flopped over under their own weight and planted themselves a few inches away. Hence the name “walking” — they migrate about 6 inches per year. I now have a 12-foot-long row of walking onions that started from those five bulbs. The bulblets are the primary harvest, and they taste like a cross between a shallot and a scallion, with a sharp bite that mellows when cooked. I harvest about 2 pounds of bulblets per square foot per season. The underground bulbs are also edible, but I leave them in place to keep the colony going. The only failure mode is planting them in a spot that stays wet in winter — the bulbs rot in saturated soil. Mine are in a raised bed with excellent drainage.

Welsh onions, also called bunching onions, are the perennial equivalent of scallions and they are far easier than any annual onion. I grow ‘Evergreen Hardy White’, a cultivar that forms clumps of 6 to 10 slender stalks and does not form a bulb. I planted 12 divisions 8 inches apart in spring 2020, and by fall I was harvesting 1-pound bunches every three weeks from April through October. The clumps expand slowly, and I divide them every third year in early spring, replanting the outer divisions and composting the center. The mistake most people make is harvesting by pulling the entire plant. Instead, use scissors to cut the stalks 2 inches above the soil line, and the clump regrows within 14 days. I get four to five cuts per clump per season. Welsh onions are hardy to zone 4 and tolerate partial shade, though full sun doubles the growth rate. I have a patch under a black walnut tree that produces half as much as the patch in full sun, but it still provides onions from March through November.

Babington’s leek is the least common allium on this list, and it is the one I am most excited about. I ordered three bulbs from a specialty nursery in 2021 and planted them 12 inches apart in a 4-foot bed. Unlike common leeks, which are biennial and must be replanted each year, Babington’s leek produces a cluster of 15 to 20 small bulbs at the base and another cluster of aerial bulblets at the top of the flower stalk. The flavor is identical to a standard leek, but milder and sweeter. I harvest the underground bulbs in October, using about half and replanting the other half. The aerial bulblets fall off in late summer and self-sow, giving me a steady supply of volunteer plants. The yield is modest — about 1 pound per plant per year — but the flavor is exceptional and the plant requires absolutely no care. The one catch is that Babington’s leek is not widely available. I bought mine from the Seed Savers Exchange member catalog for $8 per bulb. It is hardy in zones 5 through 9, and I have not seen any pest pressure in four years.

Leafy Greens That Produce for Years Without Replanting

Perennial kale, specifically the ‘Daubenton’ variety, is the only green I grow that produces leaves for 12 months a year in zone 6b with minimal protection. ‘Daubenton’ is a French heirloom that forms a shrubby plant 3 feet tall and 4 feet wide, and it does not flower like annual kale. I planted two cuttings in spring 2020, spaced 4 feet apart, and by fall they were producing 1 pound of leaves per week from May through December. In winter, I cover them with a frost blanket on nights below 15°F, and they resume production in March. The leaves are smaller and more tender than ‘Lacinato’ kale, with a milder flavor that does not get bitter after frost. The biggest problem is that ‘Daubenton’ is not grown from seed — it is propagated from cuttings, and the cuttings are expensive. I paid $12 per cutting from a specialty nursery, and the plants are not widely available. If you cannot find ‘Daubenton’, sea kale (Crambe maritima) is a worthy alternative. I grow one sea kale plant in a 2-foot-wide spot, and it produces 2 pounds of blanched shoots in spring and edible flower buds in summer. The shoots taste like a cross between asparagus and broccoli, and the plant is hardy to zone 4. The drawback is the harvest window is only 4 weeks long in spring, versus 7 months for ‘Daubenton’ kale.

Good King Henry is the forgotten perennial green that deserves a comeback. I planted three seedlings 18 inches apart in a 3-foot by 4-foot bed in spring 2021, and by the second year each plant produced 1 to 1.5 pounds of tender shoots and leaves from April through June. The young shoots taste like asparagus when steamed, and the mature leaves cook like spinach. The plant is hardy in zones 3 through 9 and thrives in poor soil — mine is growing in compacted clay that I did not amend, and it produces better than the plants I put in compost-rich beds. The seed heads that form in July contain hundreds of small seeds that self-sow aggressively. I pull up about 50 volunteer seedlings each spring and either transplant them or compost them. If you want to contain it, cut the flower stalks before they set seed. Good King Henry is not available at most nurseries. I bought seeds from Baker Creek for $4 per packet, and the germination rate was 85 percent after 14 days of cold stratification in the refrigerator.

Sorrel is the perennial green that every gardener should grow because it is the first thing you can harvest in spring. I grow ‘Belleville’, a French variety with large, tender leaves that are less acidic than common sorrel. I planted four crowns 12