What if you had to stock your refrigerator's crisper drawer just once every three years?
Planting perennial vegetables is something like that. Once they're there, all you have to do is a little maintenance to yield a few seasons worth of food.
Perennial vegetables, including the edible portions of trees, shrubs and vines, have gone largely unnoticed over the decades, aside from the ubiquitous rhubarb and asparagus beds planted in overgrown backyard patches.
Yet these plants produce vegetable crops for many years without replanting, taste delicious, yield abundantly and can be harvested when annual plants aren't available, says Eric Toensmeier, in his "Perennial Vegetables: From Artichokes to Zuiki Taro, A Gardener's Guide to Over 100 Delicious and Easy-to-Grow Edibles."
"I think the information about what's been available out there has been greatly lacking," Toensmeier said in a telephone interview from Holyoke, Mass. "But vegetable gardening is picking way up in popularity and seed companies and nurseries have begun offering more perennials. I hope those upward trends mesh and continue."
Perennial plants don't live forever but they do give you at least three years and sometimes decades of low-maintenance production once established.
"They're easy," Toensmeier said. "I've got a bad back and a busy schedule and I'm always looking for something that will make my life easier in the garden."
- Minimal soil preparation. You can break the demanding spring planting cycle with perennials, which are largely self-sustaining. Their deep root systems discourage disease and ease watering chores. Their leaves develop earlier than those on most annuals, inhibiting weed growth.
- Soil building. "With perennials, you don't have to go out there and run the Roto-tiller around," Toensmeier said. "Just spread some mulch and keep adding compost each year. People are getting smarter about minimum tillage, which doesn't disturb rich organic matter or tear up roots."
- Eco-system advantages. Perennials help prevent erosion, store water and nutrients and allow habitats and organisms to develop that are beneficial to gardens. Many serve as ground covers. Some can be fashioned into hedges.
- Extending the harvest season. Perennials are among the first vegetables to emerge from the ground in spring (nettles) and the last to give it up in the fall (kales).
- Function. Some perennials develop into the whole enchilada. They're easy to look at while at the same time good to eat.
"I grow a lot of sea kale," Toensmeier said. "The flowers are beautiful and smell like honey. It's a gorgeous plant that also happens to be an excellent edible vegetable."
What's not to like about perennial vegetables?
Some folks don't appreciate their strong flavors.
"They're not our favorite things to eat in large quantities," says Dan Gill, a consumer horticulturist with Louisiana State University's AgCenter at Baton Rouge. "I mean, how many rhubarb pies can you make compared to all the things you can do with tomatoes, onions or bell peppers? Asparagus is similar."
Many leafy perennials taste bitter if eaten uncooked. Mixing a variety of these uncommon salad fixings with traditional ingredients helps neutralize that sharpness.
Planting perennial vegetables also means making a commitment to using up precious space.
"Most vegetable gardeners want their gardens to be as productive as possible over as long a season as possible," Gill says. "Typical annual vegetables are planted, produce abundantly for a time, finish production and are removed," freeing up space.
"Most perennial vegetables are quite different in how they are grown. Take asparagus, for instance. We harvest fresh, young asparagus spears in March and April here in south Louisiana. After that, there is no more production from the asparagus. However, the asparagus plants are perennial and the same plants grow from year to year. They essentially 'own' that spot in the garden year-'round."
It's unlikely that perennials will replace annual vegetables in popularity, Toensmeier said. "I'm not advocating that," he said. "But there is a place on your property for a blend of the two. These lesser-known vegetables are not just fun novelties for the garden. Perennials are plants whose time has finally come."