Asparagus is one of the few perennial vegetables that returns year after year with little help from you. The list of vegetables that are true perennials is short: it's pretty much rhubarb and asparagus; sometimes artichokes and sorrel will return too. While the return of asparagus after a harsh winter is exciting to witness, this growing habit also means that you must sometimes move asparagus from its original planting bed to a new site in the garden.
Learn more about how and when to transplant asparagus for a yield of spears of spring to your plate for many years to come.
When to Transplant Asparagus
Asparagus enters a period of rapid growth during the spring. During this period, the plants can better renew themselves and repair any damage sustained during digging and transplanting. The exact timing depends on your climate and the weather, but early spring, as soon as you can work the ground, is the right time to begin the transplanting process.
Why to Transplant Asparagus?
Asparagus plants are long-lived and vigorous. A mature stand of asparagus plants produces spears over several weeks, up to eight weeks. During this time, a healthy plant should yield around 20 spears. When asparagus plants grow in a sunny site with good drainage, proper irrigation, and adequate nutrients, the plants multiply and become crowded over time. Some primary reasons for transplanting asparagus include:
- Crowding: If you notice a decline rather than an increase in your harvest from the past growing season, the plants may be too crowded, reducing vigor.
- Suitable site: The first garden plot you choose may not always be the best. Because asparagus is so long-lived, sometimes a site that was good several years ago loses its viability. For example, a young tree matures and casts shade that wasn't there before, or a new garden shed or other structure overshadows the bed. Look for an optimal site with loose soil, full sun, and no competition from other plants.
- Crop sharing: If you have friends with garden crops, you likely already share seeds, crowns, and divisions (and plenty of stories about gardening). This plant benefits from division, so if you've run out of room for more asparagus plants, give the gift of asparagus.
How to Dig Asparagus for Transplanting
Before you dig up your asparagus, you must prepare the new site for planting. This is to minimize the time your dug plants spend above ground.
Preparing the New Site
- Dig a generous amount of compost into the new planting site.
- Check the soil pH; it should be close to neutral, about 6.5 to 7.5.
- Dig a trench about six inches deep to place the transplants.
Digging Up Established Plants
- Dig deeply with a sharp spade.
- Cut into roots as needed to bring up manageable clumps to the soil surface.
- Shake soil from the clumps, or rinse them gently to expose the roots.
The Asparagus Dividing Process
Identify your asparagus crowns, which will delineate where to make your divisions. Each crown may have several whitish spears beginning to emerge. Roots may be very tangled, and you can tease them apart the best you can with your hands before using a sharp garden knife to separate them. If the roots are excessively tangled and overgrown, you can trim the root mass up to make it easier to replant.
Replanting Your Asparagus
Make a mound of soil mixed with compost in your prepared trench. Arrange the mounds so that each asparagus plant is about 18 inches apart. The top of the crown should be about two inches beneath the soil surface. Spread the plant's roots over the mound, and make sure the emerging spears are facing upwards. Cover the crowns with the soil and compost mixture until the trench is filled. Cover the soil surface with three inches of mulch. Mulching will stop weed seeds from germinating and preserve moisture for the newly planted crowns.
Care for Newly Transplanted Asparagus Plants
Treat your newly divided and transplanted asparagus like a brand new planting. Asparagus beds should be moist but not soggy. After the soil settles, fertilize the plants with an all-purpose balanced fertilizer. Apply one pound of granular fertilizer per 100 square feet. Keep your asparagus bed weeded by lightly cultivating around the plants. Skip the harvest on the new bed for the first season to help plants develop the energy to deliver many future productive years in your garden.