Asparagus is the rare perennial vegetable, meaning once you plant it, it will continue to grow for years to come. In fact, asparagus doesn’t begin tasting like the delicious vegetable we know and love until at least the second or third year, but will continue to produce vegetables for 15 to 20 years, sometimes more. If you’re in it for the long haul and have the space to dedicate exclusively to asparagus, here are some tips on how to grow asparagus to get you started.
TYPES OF ASPARAGUS
Each individual asparagus plant is either male or female. Male plants produce more harvestable stalks than female plants, which put much of their energy into producing seeds. Some varieties of asparagus produce almost exclusively male plants and are great if high yield is the goal. Otherwise, you can thin out female plants after planting.
Grow about 10 plants per family member, more if you eat lots of asparagus or intend to preserve it.
WHEN TO GROW
Prepare your garden bed in the fall and plant in the spring after the danger of frost has passed. Whether starting from asparagus heads, seeds, or transplants you’ll need to wait until soil temperatures reach at least 60° F – 70° F before planting. Asparagus seeds prefer even warmer temperatures (around 77° F) to germinate properly. You can sow seeds indoors 6-8 weeks prior to the last frost of the season.
WHERE TO GROW
Asparagus does best in grow zones 1-7. It is difficult to grow in warmer southern zones such as states along the gulf coast. Be sure you have at least a 4′ X 4′ section of garden that you can dedicate exclusively to asparagus for at least 2 or 3 years (more is better), otherwise it will not be worth it. This space should receive full exposure to the sun, though a little shade will not be detrimental. Be sure that other garden activities will not interfere with the space where you intend to plant your asparagus.
Asparagus does best in light soils that drain extremely well. Be sure to till and weed your garden bed thoroughly, removing any obstructions such as sticks and rocks. Fortify the soil with lots of organic material like mature compost or aged manure before planting. We suggest you till in about 3 inches of compost in the fall and then mulch over for the winter.
Keep in mind that you only plant asparagus once. The most important thing for a long-lasting, successful crop is to properly prepare the soil. The pH of the soil should be 6.0 to 6.5.
To get a head start, plant 1 year-old asparagus heads. If you start from seed, you’ll have to wait an extra year to enjoy homegrown asparagus. Don’t bother with 2 year-old heads, which often suffer from transplant shock, which delays the rate of their maturity. Be sure to only purchase healthy crowns from a reputable source.
Dig a 6″ deep trench down the center of your prepared garden bed. Plant each crown 1 to 2 feet apart (budding end up if they are flowering) and cover with 3 inches of soil. Add 2 more inches of soil two weeks later and repeat the process until you create a slight mound above the surface level of the garden.
For better results, soak your crowns in compost tea for about 20 minutes prior to planting.
Apply mulch. Leave any foliage that is killed in the winter to provide protection but remove before new growth as it appears in the spring and apply fresh mulch.
GROWING FROM SEED
If you choose to grow asparagus from seed, start them indoors in individual containers 6 to 8 weeks prior to the last frost of the winter. Keep the soil warm (about 77° F) until they sprout, then lower to 60°-70° F. Transplant seedlings outdoors only after the danger of frost has passed. They should be about 1 foot tall. Plant them 3 inches deep, 1 to 2 feet apart along the center of your prepared garden bed.
When tiny flowers begin to appear you can check to see which are male and which are female with a magnifying glass. Female blossoms have distinct, three-lobed pistils while male flowers are longer and larger. Weed out all female plants.
Water regularly for the first 2 years after planting. Keep an eye on the soil during dry spells to be sure it doesn’t dry out for more than a moment between waterings. Use mulch to retain moisture in the soil.
Top feed in the fall and the spring with compost tea.
Resist harvesting until the third season if growing from seed. You can harvest in the second year if you’ve started from 1 year-old crowns, but if you wait until the third year, your crop will be that much better.
In the 3rd year, harvest spears over a 4-week period once they become long enough to eat. You can extend this harvest period to 8 weeks in the 4th year. This will usually be in the spring before the weather gets warm. Harvest every 2 to 3 days (every day as the weather warms). Cut them off at ground level.
Be sure your asparagus is well maintained each year and you should have asparagus each season for years to come.
Do you have tips on how to grow asparagus? Let us know in the comments section below.