The Homeowners Column

The Homeowners Column

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Add perennial vegetables for perennial harvests

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Sandra Mason
State Master Gardener Coordinator
slmason@illinois.edu

As much as we want to "get out and garden", sometimes the weather just doesn't cooperate. Spring rains arrive escorted by cold wintery winds. We are inclined to stay indoors and our newly acquired garden center plants are screaming, "Forget it, I'm not going out there".

Each year many vegetables are planted in the garden as transplants or as seeds; however, some vegetables are perennial and once established give us a harvest of fresh produce each year no matter what the spring weather brings.

Winter onions (Allium cepa aggregatum), also known as walking onions, are easy to grow. Once found on every farmstead winter onion leaves and small bulbs can be harvested early and often throughout the season. They are planted from the baby onions (sets) that form at the tops of the plants. Winter onion clumps can also be divided in spring. Their "walking onion" name derives from their ability to expand quickly. The top sets fall over and root to appear to "walk" across the garden.

Asparagus (Asparagus officinalis) is one of the most popular and long lasting perennial vegetable. A well-planned bed can yield for 20 to 30 years, and harvest (not done until the third year) can last for more than a month. Asparagus crowns are planted in spring in 6-inch deep trenches. Crowns are covered with 2 inches of soil at first then as shoots grow more soil is added to fill the trench. To grow well, asparagus needs plenty of organic matter such as compost applied after harvest, consistent weeding, well-drained soil and supplemental watering during dry summers.

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Water celery (Oenanthe javanica) makes a great edible groundcover in sun or shade and is fairly easy to grow. The raw leaves, reminiscent of celery and parsley, have a milder taste when cooked. Water celery will thrive in moist soils near water or under a downspout. It spreads to form dense colonies given ideal conditions. Most gardeners start with transplants or seed.

Ostrich ferns (Matteuccia struthiopteris), also known as fiddleheads, are harvested for their tender curling shoots in early spring. Pick fiddleheads when they are still tightly curled and only a few inches tall. They can be eaten in a variety of ways, but must be cooked for at least 10 minutes to make them palatable and bring out the crisp, nutty flavor. Ostrich ferns, often grown as an ornamental groundcover, grow best in moist shady locations.

Rhubarb (Rheum x cultorum) has traditionally been cooked with strawberries and baked into pies, but its tart taste complements meats and stews. Rhubarb develops enormous leaves with red or green stalks that thrive in cool spring weather. Rhubarb stalks can be eaten raw or cooked, but the roots and leaves are poisonous. The flower stalks should also be removed but can be eaten, tasting like sour cauliflower. A side dressing of compost or fertilizer should be added in the summer and fall. When planting rhubarb, cover the crowns with soil (no more than 2 inches). Rhubarb is best grown in full sun and well-drained soil. Rhubarb is quick to rot in wet soils. Once the plants are up and growing, add a 3- to 4-inch layer of straw, compost, or other mulch to help control weeds and conserve soil moisture.

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Rhubarb is one plant that should not be eaten after a freeze. The calcium oxalate crystals that make the leaves poisonous can move into the stalks after a freeze. If the leaves look healthy, the stalks can still be eaten. If the leaves look like cooked spinach, remove the damaged stalks and place in compost pile. As new rhubarb stalks appear, they can be safely eaten.

A small investment in perennial vegetables now can lead to many years of harvest.

Thanks to University of Illinois Horticulture Educator Kelly Allsup for some of the information on perennial vegetables.

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