How to grow Asparagus

Keep them regularly watered and fertilized during the summer period and keep the bed free of weeds, especially perennial weeds which will compete for nutrients.

In the first 2 years, cut back the plumes in mid-summer to encourage new shoots to form ⁴. After 2 years, in early spring, build up the earth around the crown, to elongate the bud/shoot, and also to blanch it ⁴.

Asparagus can be sown indoors and this can be done any time between February and March, about 2 months before last frost. Soak seed for a couple of hours, then plant into individual pots containing moist seed starting mix. Place them in a warm room at approximately 15-18 degrees Celsius then, once germinated, move to to a cool, light area such as a windowsill, but keep them out of direct sunlight. Once the threat of frosts are over they will need to be gradually accustomed to conditions outside – this known as ‘hardening off’ and can take between 2-3 weeks.

Try to aim for a seed spacing of at least 1.62 feet (50.0 cm) and sow at a depth of around 0.23 inches (0.6 cm). Soil temperature should be kept higher than 21°C / 70°F to ensure good germination.

By our calculations*, you should look at sowing Asparagus about 90 days before your last frost date .

Once they are ready to be moved out into the asparagus bed proper, they can to be planted fairly deeply into well-run, well-composted, loamy soil. Cover with about 5cm of soil, deeper than the compost in the pots. Choose the asparagus bed carefully, the plants can be productive for up to 20 years. Water well and do not allow to dry out before the buds appear above the surface ⁴.

You can propagate by division in early spring, after 4 years of growth ⁴. New pieces should be planted at least 60cm apart and watered well every week until established ⁴.

Ensure that temperatures are mild and all chance of frost has passed before planting out, as Asparagus is a hardy plant.

Harvest asparagus by snapping 7 to 9 inch (15-20 cm) spears with tight tips. There is no need to cut asparagus below the soil with a knife. This may injure other buds on the crown that will send up new spears. The small stub that is left in the soil after snapping, dries up and disintegrates. A new spear does not come up at the same spot, but comes up from another bud that enlarges on another part of the crown.

As the tips of the spears start to loosen (known as “ferning out”), fiber begins to develop at the base of the spears, causing them to become tough. The diameter of the spear has no bearing on its toughness. When harvesting, the asparagus patch should be picked clean, never allowing any spears to fern out, as this gives asparagus beetles an excellent site to lay their eggs.

The year after planting crowns, asparagus can be harvested several times throughout a three-week period, depending on air temperatures. Research shows there is no need to wait two years after planting before harvesting. In fact, harvesting the year after planting will stimulate more bud production on the crown and provide greater yields in future years, as compared with waiting two years before harvesting. If planted from seed, you may have to wait an extra year.

Asparagus spears will start to emerge when the soil temperature reaches 50 degrees F. After this, growth of asparagus is dependent on air temperature. Early in the season, 7 to 9 inch spears might be harvested every 2 to 4 days. As air temperatures increase, harvesting frequencies will increase to once or twice per day, harvesting 5 to 7 inch spears before the tips start to fern out and lose quality. The second year after planting, the length of harvest can increase to about 4 to 6 weeks. The third year after planting and thereafter, harvesting can continue for 6 to 8 weeks. Since the length of harvest season will vary from year-to-year depending on air temperature, stop the harvest when the diameter of 3/4 of the spears becomes small (less then 3/8 inch). Experience gained by growing the crop will make it easier for the gardener to know when to discontinue the harvest.

When harvest is finished, snap all the spears off at ground level. Apply fertilizer. Mulch to suppress weeds. New spears will then emerge, fern out, and provide a large canopy to cover the space between the rows. Once a dense fern canopy is formed, weed growth will be shaded out.

Remove plant top when berries are red and head starts to droop. Hang to dry. Soak berries in water then wash off pulp. Air dry seeds. ²

These estimates for how long Asparagus takes to sprout, grow and harvest are from real observations from real gardeners, right around the world.

Our when to plant Asparagus estimates are relative to your last frost date.

The botanical epithet is from the Latin officinalis meaning “used medicinally”

• Asparagus was first grown in ancient greece and was primarily used as a medicine rather than an edible plant.
• Said by some to be good for urinary infections and liver problems. ³
• Said to be a good general tonic, as well as beneficial to the urinary system (gall-bladder, jaundice, kidney infections), heart disease, rheumatism, flatulence ⁴
• The root and berry-like fruits have been used as diuretics ⁴

Garden asparagus, Asperge, Argenteuil white asparagus, Argenteuil asparagus

Asparagus officinalis L.

Misspellings: Asparagas

¹ http://en.wikipedia.org/wiki/List_of_companion_plants

² The New Seed-starters Handbook; Published 1988

³ Garden Action – Asparagus

⁴ :Growing Herbs with Margaret Roberts; First published 1985