An old Chinese saying holds that the best time to plant a tree is 20 years ago and the second best time is today. Well, the same could be said about perennial vegetables. Now is a great time to add to your garden with perennial plants and give them a head start for the following year. Fall is often a calmer time of year in the garden since annuals like tomatoes and peppers have come to their end and few people are engaging in the frenzied seed-starting of early spring. You’ve just had a full season in your garden so you remember how it went: what crops did well and what didn’t, what areas looked bare or overcrowded, where the sun beats hardest or barely reaches, or where rain collects. That knowledge and timing make it the perfect time to add plants exactly where you want them.
Annuals like tomatoes, corn, and squash are the superstars of the edible garden, but perennial plants can provide tasty nutrition for years with a fraction of the work. There is the clear advantage to planting once and getting harvests over many years, but perennials have other benefits as well. They typically require little fertilizing due to extensive root systems and often grow in conditions where annuals wouldn’t thrive. These can be areas with little water, poor soil, or shade. Additionally, perennials can aid in preventing erosion on hillsides or other areas where you don’t want to routinely disturb the soil. Plus, many perennials can be divided as they grow, giving you more plants for free to add to your garden or share with friends and neighbors.
While fruit trees and berry bushes are the most obvious edible perennial plantings, there are many perennial vegetables that provide short time to harvest and satisfy those who prefer savory to sweet. Below are some of my favorite perennial vegetables that you can plant now in much of the country.
Sorrel (Rumex acetosa or Rumex scutatus) Sorrel has been a mainstay of cooking throughout the globe for centuries but for some reason is rarely seen in American grocery stores. Luckily, this lemony spinach-like green is very easy to grow. It's a great candidate for a partly shady area where other vegetables might not thrive, because sorrel will actually stay tender longer when grown in a cool spot. Sorrel is often one of the first things to pop up in the spring garden and the young and tender greens are delicious in a salad.
Depending on how hot your climate is, the plants often flower in midsummer, causing leaf production to slow. You can enjoy the flowers or cut the plant all the way to the ground to encourage a bigger fall harvest. The larger, tougher leaves of late summer and fall are perfect for soups and stews. Sorrel is hardy in USDA zone 3 and up. Sow in late fall or winter in the South or in early spring elsewhere and keep a lookout for the slender, chartreuse leaves emerging from the soil.
Egyptian Walking Onions (Allium x proliferum) Egyptian walking onions are a great way to get some onion flavor without the early seed-starting hassle of other onions, and they’re just fun! Rather than producing the flowers and subsequent seeds of most alliums, Egyptian walking onions form a cluster of miniature onions at the top of their stems called bulbils. When the bulbils are fully developed, the plant bends over to plant these in the ground and produce new onion plants, thus “walking.”
You can harvest the leaves to use like scallions or green onions, making sure to leave some plants in the ground to keep walking and growing more onions. You can also dig up the whole plant or use the bulbils themselves, which are essentially small onions and can be stored for several months once they have matured and a papery skin has formed.
Ramps (Allium tricoccum) Another member of the allium family, ramps have recently ignited a frenzy among foragers and chefs of late, appearing on menus at high-end restaurants and having entire festivals dedicated to their potent, sweet, garlic-onion flavor. Along with this popularity has come a lot of discussion about overharvesting these native plants, the numbers of which are in decline in many areas.
The good news is that ramps are easy to establish in your own garden via transplanting. Look for ramps with the roots still attached at your local farmers market in spring or dig your own (responsibly and where legally permitted). Find a spot similar to their natural conditions; they prefer moist but well-draining areas with partial shade to protect them from hot, sunny days. Ramps mature and spread slowly, so resist the urge to harvest more than a few leaves until the colony has established.
Horseradish (Armoracia rusticana) Horseradish packs a lot of flavor punch into a small package and grows extremely easily from root cuttings. If you know someone who has it in their garden, they will probably be happy to let you dig out a piece for yourself and you can be whipping up spicy sauces in no time.
To plant, dig a trench and place root cuttings at a 45 degree angle with the skinnier part of the roots facing downward and cover with 3 inches of soil. The plant grows best in cool, moist conditions and prefers full sun. Just be aware that it can spread aggressively, so growing in partial shade or a container can limit its growth. The roots get tougher and more fibrous in the plant’s second year, so it’s best to harvest in late fall before the ground freezes, leaving a small piece of root in the ground to regrow the following year.
Sunchokes (Helianthus tuberosus) Sunchokes, also called Jerusalem Artichokes, do double duty in the garden as sources of food and beauty. These members of the sunflower family are native to central North America and their tubers are nutrient-dense and delicious like a nuttier, crunchy potato. They grow between 5 to 10 feet tall and are topped with clusters of bright yellow flowers in summer months.
Sunchokes prefer full sun and rich soil but will grow just about anywhere and are drought tolerant. The tubers can be planted fall through spring depending on your local climate and should be mulched to protect against hard freezes. Sunchokes are ready about 150 days from the plant emerging but will taste sweeter after a light frost. Any tubers left in the ground will produce more plants the following year, so either dig them all up and replant or leave however many you would like to regrow. Like horseradish, sunchokes can get out of control in the garden, so grow in a bed with metal or wooden sides to better manage their spread.
Once you’ve decided which perennial vegetables to add to your garden, it’s as easy as picking a day with nice weather and putting them in the ground. Because of soil’s insulating properties, underground temperatures are actually warmer in the fall than the spring since we've just been through a long warm period. These warm soil temperatures combined with cool air are perfect for plants to develop strong roots—just make sure you get the plants in several weeks before the soil freezes solid and apply a thick layer of mulch once the nighttime temperatures are consistently below freezing. This will provide more insulation for the roots to establish and also protect against “frost heave” where soil movement from the freeze-and-thaw cycle throws new plants up out of the ground and makes the roots susceptible to frost damage. It’s a good idea to mark where you planted them as it might be hard to remember the following spring. Your future self will thank you!