Asparagus Growing Instructions

Asparagus Growing Instructions

How to Successfully Grow Asparagus

Plant in full or 1/2-day sun
Avoid competition from trees and shrubs by planting at least 4 feet away
The area where you plant the asparagus must have good drainage, i.e., if your site is waterlogged in the winter, plant in a raised bed to improve drainage
In most regions, the crown should initially be covered by ½” of soil and fill trenches as plants grow
- In zone 8 the crown should be covered by 1”
- In very cold regions, 6” to 8” of soil is required
Do not over water
Fertilize and add abundant compost yearly
- In wet areas the compost should be applied in June/ July
- In dry or cold areas apply compost in the Fall

A Note on Soil

All soils are different and a soil test can confirm your exact needs but here are a few guidelines:

Clay soils need to have abundant composted organic material tilled in
If the soils are acid, bone meal or lime will be beneficial
Sandy loam soil will also benefit from bone meal and lime. Lime at rate of 4 pounds per 100 square feet and bone meal at 4 ounces per 5 feet of trench. A pH of 6.2 - 7.2 is best in both clay or sandy loam soils.

A soil test can confirm your exact needs.

Asparagus Growing Instructions

The perfect time for planting is usually around 6 weeks before the last frost date. The soil temperatures should be close to 45°F and the air temperatures should be between 40°F and 70°F.

Site Preparation

Prepare soil by removing all perennial weeds and digging in aged manure or compost. Please use aged and cold compost; if it is not aged and totally cold, it will compost the newly planted asparagus crowns instead of growing them.

Next, dig a V shaped trench, no more than 3-10" deep. Planting too deep will reduce yield. Apply around 2lbs of 0-20-0 Super phosphate fertilizer, per 100’ row, to the bottom of the trench.

Most rows should be 4-5 feet apart to create a walking path.

*2 or 3 rows spaced 1 to 1 ½’ apart and then a walking path is good in regions with low humidity in the summer and/or areas that are very windy. This keeps the plants from blowing over in the wind.

Planting

Crown spacing ranges 6” to 1 ½’ depending on your soil type and the availability of water for irrigation. You’ll want to plant them further apart in areas with humid summers, less rainfall during the growing season, or wherever irrigation water is limited.

If planted on a slope run rows up and down the slope to improve drainage

Make sure the crown buds are upright and place them along the edge of the trench. Do not compact soil or the emergence of asparagus spears will be reduced.

Cover with a ½” of soil and add up to 5” as the plants grow depending on how cold your winter is. *Contact your local Ag Extension agent for correct final cover depth in your area.

Water after planting if weather is dry.

Fertilize with 2 to 3lbs of 10/20/10, per 20’ of row, after fronds are 6” tall.

Maintenance of Bed:

Keep beds weeded and clean to minimize disease and insect problems. After asparagus fronds have frozen and browned in the fall cut to ground and remove from asparagus bed.

Watering is determined by your plant spacing, time of year, and rainfall. If you don’t have adequate soil moisture in the spring before the spears appear - water to keep soil moist, but not waterlogged. During the season, if you have a tight plant spacing (6 inches to 1 foot) you will need to water more often than if your plant spacing is 1-1/2 feet. Usually once every week the first year and every 2 -3 weeks after the first year.

Once established, asparagus roots can be 6’ – 8’ deep. Do not water too often or roots can rot. Let the top several inches of the soil dry before watering again.

Fertilize in the spring after the spears have formed fern fronds. Several inches of aged manure or rich compost on top works well, plus 2 to 3lbs of 10/20/10 per 20’ of row is sufficient. Fertilizer can be chemical or organic. Mulch to maintain moisture during the dry months and to suppress weed growth.

In the Fall in USDA Zones 3 to 5, if crowns are covered with several inches of soil, add 4 to 5 inches of mulch for added winter protection.

Harvesting: May - June

Do not cut spears the first year. Be patient, the new plants need the photosynthesis energy to grow and store food in the roots for the next years spears. You can cut one or two cuttings the second year and 3 or more cutting the 3rd year. Stop cutting when the spears become smaller than 3/8 inch in diameter. Snap or cut the spears at slightly below ground level. Leave smaller spears to develop into fronds and leave growing till fall. Do not cut near the crown or you may cut new spears that haven’t developed yet. You may find an asparagus knife/weeding tool effective in helping to cut the spears slightly below grown level. Asparagus knives are easily found online, including on our website. Cut the spears in the morning when it is cooler and immerse them in an ice bath to remove heat. After draining, place asparagus in a plastic bag and refrigerate until ready to use.

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Click here to view out Purple Passion Asparagus Crowns

Scenic Hill Farm Nursery, 2820 NW Scenic Drive, Albany, OR 97321, 541-990-6099