Take guess out of asparagus: These perennial vegetables grow well in Northern California
Q: How do I grow asparagus? Is it better to plant from seed or transplants? Are there any other perennial vegetable plants that I can plant that will come back every year?
A. Asparagus is easy to grow but planting requires special preparation and care.
It’s best to purchase bare root plants from local nurseries. These will produce much sooner than growing plants from seed. If you start asparagus from seed it can take three years or more before you start to get heathy enough stalks to harvest.
Planting bed preparation is important to a long-lived productive asparagus patch.
Start by digging a trench with inches deep and 12 inches wide, and work compost and fertilizer into the bottom. Asparagus likes a lot of organic matter in the soil, so a 50/50 mix of soil and compost in the trench is ideal.
Before planting, soak bare root plants in water for about an hour to make sure they’re well hydrated.
Plant the asparagus roots — the crowns — every 18 inches and cover with enriched soil.
As the spears grow, fill in the trench, again with enriched soil.
Since a bed will produce for up to 15 years, you need to find a permanent spot for it, and remember that long-term weeding will be necessary as well as long-term fertilizing. You can mulch beds to cut down on the weeds. A layer of organic matter should be added to the asparagus bed each year after harvest to keep plants productive.
Don’t harvest the first spring. The second spring, take a limited harvest, cut spears at ground level for only a couple of weeks. By the third spring they should be well established, and you should be able to harvest for three weeks or so. After harvest period allow to grow into tall ferns and leave the ferns until they’ve turned brown. Then cut them back in the fall.
Other perennial vegetables that grow well here are artichokes, walking onions and sunchokes — also known as Jerusalem artichokes.
Artichoke plants can grow large: Three feet by three feet. They’re quite structurally stunning, making them a great edible landscaping plant. In our climate, at lower elevations, artichokes do best with morning sun only, and plenty of regular water. Artichokes are short lived plants, producing for about five years.
Sunchokes are a member of the sunflower family and grow to about four feet tall. They have small sunflower-like blooms. These plants are grown for their tubers, harvested in late summer. The plants can become invasive if tubers are left in the ground, so care should be taken as to where they are planted. Once established plants will regrow each year from tubers.
Walking onions are a truly delightful plant. They reproduce by topsets, a cluster of bulbils at the top of the stalk, where the flowers and seeds would normally be. The stalks eventually flop over from the weight of the bulbils if not harvested, and replant themselves, thus beginning their “walk” across the ground. Walking onions taste similar to a shallot, but are a bit spicier. Once established they will grow for years with little care.
The Shasta Master Gardeners Program can be reached by phone at 530-242-2219 or email email@example.com. The gardener office is staffed by volunteers trained by the University of California to answer gardeners' questions using information based on scientific research.