Perennial vegetables may take more patience than those you plant and harvest in one growing season. Many don't yield a harvest the first year after planting, but the rewards of a return harvest year after year make them worth the effort. Try these vegetables you plant once and harvest for several years. Artichoke (Cynara scolymus) is perennial in Zones 9 and warmer. In Zones 7 and 8, it overwinters in the ground if mulched. In colder zones, treat artichoke as a tender perennial, digging it up and storing it like a bulb over the winter, or grow it as an annual crop.
Asparagus (Asparagus officinalis) can produce for up to 30 years, so plan on a long and fruitful re-lationship with these plants. For more color, add a purple variety to your mix. Grow asparagus in Zones 4-8; in warmer zones, the plants never go into their required dormancy.
Chayote (Sechium edule) looks like a large green pear with a cleft. Use it in cooking as you would summer squash. This perennial vine can grow up to 90 feet and is hardy in Zones 8-10. Where the ground freezes to only an inch deep, the vines die back, but you can protect the roots with 10 inches of mulch. In climates colder than Zone 8, grow chayote as an annual vine.
Horseradish (Armoracia rusticana) readily grows in most garden soils in Zones 4-8. In colder zones, overwinter the roots as you would bulbs. Wear gloves when harvesting the root; it contains an oil similar to that found in hot peppers and can burn your hands. Plant with caution. It can become invasive.
Jerusalem artichoke (Helianthus tuberosus) tubers are planted like potatoes. Harvest the tubers af-ter the plant dies back in fall. In Zones 4-9, leave a few tubers in the ground to grow the following season. In colder zones, overwinter the tubers as you would bulbs. Grow the tubers in an area where you can control the plants, because they can become invasive.
Rhubarb (Rheum x cultorum) can be grown in Zones 2-9, although it does best where the winters are cold enough to freeze the ground. In warmer zones, grow it as a winter annual. Use the thick stalks in cooking; the leaves contain toxic levels of oxalic acid and should not be eaten.