How to Plant and Grow Asparagus
in Your Home Vegetable Garden
Asparagus officinalisAsparagus plants are long lived, perennial vegetables that have been cultivated for over 2000 years.
They take a considerable amount of garden space, but in return you will be rewarded with
successive crops of delicious young spears for 6-10 weeks, every year in the spring
and three foot tall spires of decorative, layered, fern-like foliage in the summer.
Asparagus are dioecious plants. They can be purchased as male or female plants.
Growing Requirements for Asparagus PlantsAsparagus plants should be grown in a site that receives full sun for 7-8 hours each day except in hotter regions where they can be grown in partial shade.
Because Asparagus plants will be left undisturbed for up to 20 years
the site selection and the soil preparation are crutial.
Asparagus plants prefer a soil pH of 6.5-7.5 and
they will not grow well at all if the pH falls below 6.0,
so it is important to test and adjust your soil pH
before making further adjustments or additions to the soil.
Asparagus are not especially nitrogen hungry plants,
but they do need phosphorus and potassium to thrive, so unless your soil has been tested,
it is a good idea to till in a good granular fertilizer with an N-P-K ratio of 10-20-10
at a rate of 10 lbs. per 500 sq.ft. Mix generous amounts of compost, aged cow manure
and other organic matter into the entire planting area as well.
Be sure to remove any perennial weeds you encounter during preparation.
you should add coarse builders sand, or consider
growing your Asparagus in a raised planting bed.
Planting Asparagus Crowns
Asparagus should be planted in the spring, after the soil temperature reaches 50°.
Asparagus plants are normally sold as 1 or 2 year old crowns.
Their fleshy roots should not be allowed to dry out.
Once the soil has been prepared and raked smooth, you are ready to plant your Asparagus.
Dig a flat-bottomed trench 12" wide and 6"-8" deep.
Add a 3"-4" high mounded ridge of loose, rich soil down the center of the trench.
Additional rows should be spaced five feet apart.
Sprinkle superphosphate fertilizer (0-20-0) in the bottom of the trench
at the rate of 2 lbs. per 50 feet of row. Soak the soil thoroughly!
Spread the roots out evenly over the mound and space the crowns 12"-15" apart.
Add sufficient soil to the trench to bring the level up to the crown,
leaving the growing tip exposed. Do not pack the soil! Water thoroughly.
As the young sprouts grow, gradually refill the trench to ground level,
but allow 3"-4" of the stem to remain exposed.
Growing Asparagus from Seed
Asparagus can be grown from seed, but it is time consuming and adds another year
to the wait for your first harvest. However, it a far less expensive method
of growing Asparagus if you plan on a large crop.
Soak Asparagus seeds in warm water for 48 hours before sowing!
Asparagus seeds can be sown in the garden after the soil has warmed thoroughly in the spring.
Plant seeds 1" deep and 3"-4" apart, in loose rich soil in a sunny area of the garden.
During their second year, transplant them 15" apart in their permanent, well prepared bed.
For better results, start Asparagus seeds in pots indoors in mid winter.
Maintain a temperature in the growing medium of 75°-80° until germination, which takes 14-21 days.
Keep the young plants in a warm, brightly lit area until they can be planted in their permanent,
prepared bed after the soil warms up in the spring.
Maintaining your Asparagus Bed.Asparagus are very thirsty plants that require regular, thorough watering.
Do not cut down the fern growth at the end of the growing season.
Allow the foliage to die back naturally and become part of heavy layer
of mulch that should be added before winter.
Do not remove the mulch until all danger of frost has passed.
Cut the dead canes back to the ground in the spring before new growth begins.
Asparagus Pests and ProblemsBe vigilant about keeping your Asparagus bed weed free.
Take precautions to protect new growth from slugs and snails.
Asparagus beetles and their larvae chew on tender underground spears before they emerge,
leaving the Asparagus spear scarred and sometimes distorted, but still edible.
Later in the season, they feed on the stems of the fern growth, causing it to turn brown
and disabling it from the ability to provide food for the crown, seriously reducing the next year's crop.
Hand pick and squash any Asparagus beetles or their green larvae that you see.
fungicide when the fern growth reaches 3 or 4 feet, following the label directions carefully.
Buy hybrid Asparagus plants that are resistant to these fungi.
Do not harvest anything from crown grown Asparagus plants in their first year, or the second year for seed grown plants.
The next year you should limit the harvest period to 4 or 5 weeks. In subsequent years you should be able to harvest Asparagus for 8 weeks or longer.
Asparagus spears will start to emerge in the spring
when they reach 6"-8" tall and while the tips are still tight.
Use care to not injure underground growth if you are using a knife.
Stop harvesting when the spears start getting smaller.
The remaining spears will then grow into their ferning stage,
which will feed the crown for next year's years crop.