Asparagus – The Jewel of Spring

For those who enjoy asparagus, it may be the most anticipated spring vegetable to show up in the garden. This perennial plant has been a delicacy since Roman times and any home gardener can grow and enjoy this vegetable with some careful planning and preparation. 

Asparagus is a perennial that will produce for 10-15 years if it is planted and managed properly. Start by finding the perfect spot in your garden. Asparagus will need a permanent home with a sunny location and well-drained soil. It grows best in medium textured soils with a soil pH between 6.5-7.0.

Asparagus can be grown from seeds but most home gardeners choose to plant asparagus crowns purchased from seed catalogs or from local nurseries. When purchasing, review the varieties available. Hybrid varieties are mostly all-male plants with the open pollinated varieties containing male and female plants. The male varieties produce no seeds so all their energy goes into spear production which generates a higher yield of larger spears. The female varieties put their energy into seed production which generates a lower yield of smaller spears.

Your soil type will dictate the depth of your trench – medium textured soils dig a trench 8-10 inches deep; in heavy clay soils reduce trench to 6 inches and sandy soils increase trench to 12 inches. Place the crowns "head-to-toe" (bud-to-root tip) in a line down the trench, so the buds of the crowns are spaced above 12 inches apart and cover with 2-3 inches of soil. Rows of asparagus should be spaced at least 4 feet apart. Another method of planting is to place the crown in the trench on top of a small mound of soil, spread the roots out around the crown (“octopus” formation) then cover 2-3 inches with soil. Click here for growing guide.

As tempting as it may be, do not harvest asparagus spears the first spring after planting. Lightly harvest during the second spring then harvest normally in subsequent years.
At the end of the harvest, start getting your asparagus ready for next year. Continue to water regularly, control the weeds, and fertilize. Allow your last spears to go to ferns. When the ferns die down in the fall, mow them and leave them for mulch. 

Always be on the look-out for pests and diseases that can damage your asparagus.

The Asparagus Aphid, Asparagus beetle and the beetle larvae feed on leaves and above ground plant parts. The Cutworms, asparagus miner, and grasshoppers feed on the lower stem close to the ground and/or the roots. 

There are also a variety of diseases, such as Purple Spot, Rust, Fusarium Crown, Root and Lower Stem Rot and Phytophthora Crown, Root/Spear Rot which can affect the asparagus above and below the ground.

Your planning, maintenance and patience will be rewarded with numerous harvests of tender, green asparagus spears to enjoy every spring for years to come!

Growing Asparagus Requires Planning, But Gives Many Years of Reward

Asparagus is a shining gem of springtime in Southwestern Idaho. Packed full of nutrition and boasting a delightful flavor, asparagus will give you 15 years or so of production from one well thought out planting. When mature, one plant produces about ½ pound of asparagus a year. It is an early producer, so you can plan on fresh vegetables gracing your table much sooner than neighbors who haven’t established asparagus in their garden planning. Getting this productive perennial started growing in the right spot and with the right preparation, is the most important step for the home gardener with regard to their plans to grow asparagus. 

Where to Plant?

Due to it being a perennial, planting it at the side or center of your garden can be ideal so it doesn’t interfere with plot preparation and cultivation of annual crops. It can grow to a height of 3 to 8 feet tall, so a bed on the north or east side of your regular garden plot in a spot that gets approximately 7 hours of full sun each day is ideal. Because asparagus roots can be deeper than 6’, even raised beds are an option. Consider that a 25’ to 50’ row will supply the typical family with enough asparagus for regular use.

Site Preparation

Asparagus prefers deep, well-drained loam or sandy loam with a pH of 6.5 to 7.5. If the soil retains too much moisture, asparagus can die from root rot. It will grow in soil conditions that are not ideal, but the life of the plant and the production will be reduced. It is best to begin site preparation in the fall by breaking up the soil to around 18” deep and working in rich organic matter like mature compost or aged manure. Simultaneously, add 4 to 5 pounds of 5-10-10 fertilizer per 100 square feet. Prepare an area that is 3’ to 4’ wide and as long as necessary to supply the amount of asparagus you wish to reap from your harvest each year, after plants mature.  

Planting

You can start growing asparagus from seed or crowns. Most choose to start with one year old crowns to get to harvest faster. Choose large crowns that have not dried out - male crowns are more productive than female crowns. Older crowns can be purchased, but they are more expensive and much harder to plant successfully. If you are working with prepared good soil, dig a trench 12” to 18” wide and 6” to 8” deep. If you are working with heavier soil, use the more shallow depth. Spread mature compost or aged manure in the bottom and cover with about an inch of garden soil. Place crowns in trench about 18” apart, while spreading roots to insure they lie flat. During the growing season, continue adding soil or aged manure until the trench is full, being careful not to cover foliage. 

Maintenance

For ongoing high spear yields, it is recommended to fertilize before plants start growing each spring and again in the fall after harvest using 1 ¼ pounds of 5-10-10 fertilizer per 100 square feet each time. A deep watering once every couple of weeks during dry season is plenty due to the deep root system. Weeding should be done somewhat regularly, but do not cultivate deeply as you can encourage disease if crowns are damaged. Adding a thick layer of mulch will help reduce weeds. You may use herbicides approved for asparagus, but mulching and hand cultivating is favored. Take the time to learn about dealing with pests like Asparagus Beetles and diseases like Fusarium Wilt and Root Rot.

Harvest

The reward for taking the time to plan and prepare your plot, and the patience you exhibit for several years is the harvest! It is recommended not to harvest any asparagus until the third year to allow the crowns to be mature. You may remove a small harvest for approximately 3 weeks during the third year. You can harvest for 6 to 8 weeks for every year after that. Harvest in the morning when spears are crisp. Spears should be 5” to 7” when harvested. Snapping the spears is advised over cutting to avoid damaging emerging spears. Refrigerate spears promptly after harvesting. An excellent, simple recipe for asparagus is Oven Roasted Asparagus