Growing Asparagus

Growing Asparagus

Asparagus spears
Asparagus spears

Asparagus is a really interesting plant, very tasty, expensive to buy but easy to grow. Growing asparagus is a test of will, however. The plants need time to develop strong, thick roots that can produce a continuous supply of spears. They required deep well drained soil, full sun – and patience…

Here is what is involved. Asparagus is a heavy feeder and appreciates rich, loose, well composted and manured ground. The plants are planted from seeds, but more often from ‘crowns’, or the growing top of a root mass. Growing from seed requires and extra year before you can start harvesting spears. They do best for me with seasonal applications of compost top-dressing – the best organic garden fertilizer.

Compost is also a perfect vegetable garden mulch. Not only does it enrich the soil, it prevents evaporation from the soil which would bring salts to the surface.

Here are some garden seed catalogs that feature asparagus: Baker Creek (seeds), Seeds of Change (crowns)

Asparagus plant
Asparagus plant

When the soil warms the crowns use their stored energy to sent up new plant shoots – the ‘spears’ we eat. If the spears are allowed to grow, they develop into a tall, feathery shoot. The foliage converts sunlight and the nutrients in the ground into sugars which are stored in the root crowns for the next year.

The plants exert significant energy doing this, and over-harvesting will exhaust the plants’ energy. Whenever spears begin to thin, stop picking and let the plants recover for the rest of the year.

Asparagus Growth
Asparagus Growth Progression

Asparagus is usually planted in a trench. The soil at the bottom of the trench should be heavily enriched and manured a week or two before planting. Include blood and bone meal, leaf mold and compost.Work the nutrients into the soil, berm up a row along the center of the trench and reserve some of the enriched soil to cover the crowns.

asparagus root system
Asparagus root system

Root crowns should weigh a couple of ounces but often you have to settle for much less. Reject any crowns that show fungus, look withered, soggy or slimy, or have a moldy odor.

Asparagus Tall
Asparagus Tall

Now you can plant in your ‘rested’ bed. Spread the crowns out with the root tips fanned out evenly. Cover with the Crowns wit 2″ – 3″ of the enriched garden soil you pulled aside. Keep the crowns moist, and continue to add more of the enriched soil to the bed as the spears grow, leaving the top few inches exposed.

Do not harvest any of the spears for the first year. Let the crowns develop and crown the roots and rhizome. Harvest lightly for 3 to 4 weeks the second season, then let the asparagus recover. Your harvest intensity and production period can be increased in following years.

For more information on growing asparagus, please visit the following sites:

Growing Asparagus in the Garden, UC Davis Vegetable Research and Information Center (Right-click the link and chose ‘Save As…’ to download the printable, 2-page pdf to your computer)

Ohio State Extension Service ‘Asparagus Growing in the Home Garden‘ Fact Sheet