Delicious Edible Perennials Add Interest to Backyard Vegetable GardensMay 31, 2022 ● By Lisa Hilgenberg
Asparagus, photo credit: Chicago Botanic Garden
Edible perennials are a useful group of plants to grow in home gardens. Often thought of as the economizers of an edible landscape, they are recognized as plants that keep on giving, year after year. When we think of vegetable gardens, we often think about annual vegetables, those plants living for one growing season such as beans, tomatoes and squash. Adding perennial plants or those that live for three years or more can provide a perpetual harvest, and add interest to our gardens as well. They require less work than annual plants, along with less water, fertilizer and maintenance.
Integrating a few edible perennial plants increases the garden’s productivity and can solve problems in the landscape. Strawberries and sorrel are beautiful bed edgers, and rhubarb’s dramatic leaves look tropical and textural in the garden. Here are some tips and plant variety suggestions for adding edible perennials to the mix.
Recommended Edible Perennials for Vegetable Gardens
Asparagus: Asparagus officinalis is perennial, but requires three seasons to mature. Take a long-term approach when siting the asparagus patch. The first season, asparagus crowns develop roots. Ferny plants form during the second year, and by the third season, a limited harvest can be expected. It fully reaches peak productively between years six to eight. Weed and compost the bed prior to planting asparagus. Plant the crowns along a furrow six to eight inches deep in heavy clay soil. Spread the roots out horizontally. Keep weed-free and water one inch per week throughout the season. Grilled asparagus is a spring delicacy. Cultivars include Purple Knight and Jersey Knight.
Chives: Allium schoenoprasum—eat the leaves and flowers. Chives are great allies planted underneath fruit trees as pest deterrents or as beneficial companions in the vegetable bed. Chives can help deter loopers from Brassica family plants like cabbages and collards. Garlic chives, Allium tuberosum, have wide, flat leaves and their flowers make pretty additions to flower bouquets.
Hops: Hops clamber up to 25 feet in one season, winding clockwise around whatever support they can find. They are not only the most important ingredient (natural preservative) used in brewing beer, but can be planted on pergolas or wrought iron fences as privacy screening. Hops require a partially sunny to full sun location with rich, moist, well-drained soils. Humulus lupulus cultivars can be aromatic with flowery fragrance or bittering with heavy herbal notes. Late summer harvests of hops (the female cones of the plant that carry the aromatic resinous compound called lupulin) could become material for crafts—hop wreaths and spillers in flower arrangements.
Horseradish: A brick-edged barrier such as the parkway
between the driveway and the street might be ideal for a horseradish planting.
Locate horseradish carefully; it can be a vigorous spreader if planted in among
vegetables or next to open soil. Amoracia
rusticana, ‘Big Top’, or the frilly white splotched leaves of ‘Varigata’ are two-to three-foot plants with attractive foliage.
Sorrel: As perennial as spring itself, garden sorrel, Rumex acetosa, is a welcome sight in the garden after a long winter. The sour, lemony leaves are delicious in eggs, salads and soups. Many culinarists prefer using French sorrel (Rumex scutatus) because it is less acidic. The first crop in the spring, the young leaves have the best flavor. Sorrel grows in clumps and can be an attractive edging plant growing around garden beds.
Strawberries: Sweet when picked right from the garden, strawberries are a unique herbaceous perennial and the only fruit with seeds on the outside rather than the inside. They are easy to grow with a careful attention to their cultural needs. Planting depth matters, and should not be too deep; rather, just at the midpoint of the crown at soil level. Consider growing berries in hanging baskets, towers and herb pots. June-bearing strawberries are thought to have more flavor and perfume. They set buds in the fall and produce a heavy crop of berries the following June. These spread by producing runners. Everbearing strawberries produce one crop in June and another in late summer. ‘Tristar’ is the gold standard of day-neutral varieties and produces a continuous crop. Mara des Bois has the highest flower and fragrance of the everbearing types.
Ramps: Commonly referred to as wild leeks, ramps are native to the Mississippi Valley and grow and naturalize in wooded areas. It’s interesting to note, “Indigenous peoples referred to the area around the southern part of Lake Michigan by the name they used for the dense colonies of this plant that grew there in the 17th century as CicagaWuni or shikako, which Europeans pronounced as ‘Chicago,’” according to Susan Mahr, at the University of Wisconsin-Madison. It’s possible to find seeds bulbs or plants of Allium tricoccum in mail order catalogs; never collect from the wild. Plant them in moist, shady areas of the yard.
Rhubarb: Plant rhubarb crowns in a sunny location in the garden and in well-drained, fertile soils. Space plants three feet apart. Cultivate, weed and water during the first two years. Avoid harvesting until the third year to allow the roots and crowns to fully develop. Rhubarb can be harvested for eight weeks up until the middle of June. Harvest stalks by hand, grasping each stalk down at the base, gently pulling and twisting at the same time. Cut off and discard the leaves; they are moderately poisonous, possessing large amounts of oxalic acid. Rheum rhabarbarum ‘Canada Red’ and ‘Valentine’ are excellent for home gardeners.
Lisa Hilgenberg is the horticulturist at the Regenstein Fruit and Vegetable Garden in the Chicago Botanic Garden, located at 1000 Lake Cook Rd., in Glencoe. For more information, call 847-835-5440 or visit ChicagoBotanic.org. Follow her on Twitter @hilgenberg8 and on Instagram @hilgenberg8. Follow the Chicago Botanic Garden on Facebook @Chicago Botanic Garden and on Twitter and Instagram @ChicagoBotanic.