How Does Asparagus Grow?

How Does Asparagus Grow / how to guide is primarily focused on high altitude gardening in the Park City Utah area.  The all male varieties like Jersey Giant and Jersey Knight perform well in Utah. Asparagus is a long term relationship.  Just like a pet in the 1st two years this plant is a pup.  You have to give it a little more attentive care, but by the time it becomes a mature plant, you'll have a reliable member of your garden for decade plus.  Asparagus likes a sunny, fertile, and well drained areas of the garden.   Add plenty of compost (organic material) and phosphorus fertilizer into the area before planting.  Plant the Asparagus crowns 1-foot (12 inches) apart in furrows 8 inches deep, in the spring.  Cover the crowns with 2 inches of soil and slowly fill the furrows over the rest of the summer.  Fertilize the plants with nitrogen after the plant is established.  Water regularly throughout the summer. 2 years after planting, harvest all the asparagus spears for 4 weeks.  Harvest can be 6-8 weeks in the following years.  After harvest, fertilize and water the plants to encourage good fern growth and control pests.  When ferns die in the fall, mow and mulch them on the beds.

How Long Does it Take to Grow Asparagus

How long does it take to grow Asparagus?  Asparagus harvest begins 2 years after planting.  Plants may be harvested for up to 4 weeks the 1st year.  Harvest can be 6-8 weeks the following years.  How long will asparagus last?  Expect the plants to produce spears for 10-15 years.

Soil Preparation

Before planting, control all perennial weeds.  Incorporate 2-4 inches of well composted organic matter.  Apply high phosphate fertilizer (11-52-0) fertilizer to area.  Work compost and fertilizer into soil to a depth of 6 inches.


Purchase quality 1 year-old crowns from local garden centers or seed catalogs.  Crowns should have 8-10 large roots and a healthy bud cluster.  You may also establish asparagus from transplants grown from seed.  Plant seed in january for transplanting in April.

Planting and Spacing


Asparagus crowns should be planted in 8 inch deep furrows in April.  Space plants 12 inches apart in the row, with rows 3-4 feet apart.  Cover crown with 2 inches of soil.  Add additional soil to the furrow by cultivation during the year but do not bury those ferns already established.


During the first 2 years after planting, water frequently by supplying 1 to 2 inches per week in one application.  Use drip irrigation if possible.  Mulch around the plant with compost or grass clippings to conserve soil moisture and reduce weed growth.  Irrigation can be reduced to every 2-3 weeks after year 4.  Irrigate so that moisture goes down to 4 feet in the soil.


After harvest, fertilize with a complete fertilizer (16-16-8).   This is difficult NPK ratio to find but you'd be better off using a organic fertilizer even it the NPK ratios aren't as high.

Oil based fertilizers/chemical fertilizers do absolutely nothing for your soil. They fool your plants by bypassing the micro-organisms in the soil which turn organic matter into nutrients. As time goes by your soil, its natural nutrients along with the micro-organisms (fungi and bacteria) become less and less until finally you end up with soil devoid of organic matter. Ever heard of worn out soil? Of old farmland that won't produce? It's caused by overuse of 13-13-13 of 12-24-12 of 22-0-0 and any and all of the artificial chemical nitrates. Organic fertilizers build up the soil. By using natural organic fertilizers, you will, over a relatively short period of time, use less fertilizer per square foot instead of having to use more and more to get the same results of using chemical fertilizers.

I recommend a product to build fungi and bacteria called GreenNGro


Growing Asparagus

How to Harvest Asparagus

Asparagus harvest begins 2 years after planting.  Plants may be harvested for up to 4 weeks the first year.  Cut 9 inch tall spears at ground level.  Remove all emerging spears during harvest since tall growing spears suppress further spear growth.  Harvest for 6-8 weeks from year 5.  Stop harvesting when the majority of spears are smaller than a pencil in diameter.


After Harvest Plant Care: After harvest is completed, control weeds and then allow spears to develop into fern.  Fertilize the beds, water regularly, and control pests.  After ferns die in the fall, mow them down and use as a soil mulch.  Avoid tilling asparagus beds since this damages the crown.


Productivity:  A mature asparagus plant can produce 1/2 to 3/4 pounds of spears during the complete harvest period.  Plant approximately 20 plants per family member in order to have sufficient spears for fresh consumption and storage purposes.  Spears will store for 3-5 days under refrigeration.


Can you harvest asparagus at other times of the year beside spring?  You can, but generally these plants do not yield well and the life span of the bed is greatly reduced.