Spring is here, officially, but that doesn’t mean we should get overly excited and go clean up our landscape beds just yet. However, Asparagus will soon be emerging from previous plantings and new plantings can be started soon.
Planting & Care
Asparagus is a perennial vegetable that will come back every year providing you with harvest annually without having to plant it every year. Asparagus is planted as crowns in the spring when soil temperatures have reached 50 degrees, check your soil temperature at go.unl.edu/soiltemperature. Dig a trench 6-8 inches deep and 12 inches wide and place the crowns in the trench and cover with soil. Do not compact the soil around the crowns and be sure to place the crowns with the roots downward and the buds upward in the soil.
Once planted, wait to harvest until the third year to give the roots time to become fully established before beginning harvest. Asparagus can be planted from seeds, but it will add one more year to the establishment period before harvest is initiated.
Asparagus needs to be watered when precipitation is not present. It should receive about 1 inch of water weekly, which may need to be supplemented during periods of drought. Ensure that you are watering down to where the roots are, at 6-8 inches deep by using a screwdriver to probe the soil for moisture.
For fertilizer, you should start with a soil sample to check where your soil nutrient levels are when starting the bed and every 3 years after planting. If necessary, a typical garden fertilizer (10-10-10) will benefit plants annually. If you start to notice that the plants aren’t producing as well as they did after multiple years in the ground, it is likely that fertilizer is necessary.
Weed Control
Weeds are one of the most common problems for gardeners of asparagus. For years, many gardeners used the salt water produced when making ice cream around asparagus, this is no longer advised. Asparagus can survive in a high salt condition due to the deep roots, but salt can build up and cause asparagus to die over time and create a crust which blocks water absorption to plants causing drought stress. Using any type of salt in the lawn or landscape is NOT a recommended practice for weed control in any situation.
The better option for weed control in asparagus would be to use mulch around the plants. Any type of organic mulch will work for weed control around the asparagus including grass clippings, wood chips, straw, or hay. If using grass clippings, be sure that it hasn’t been treated with herbicides or follow the label for length of time to wait after application.
Preen can be used to help reduce weeds in asparagus. Make sure it is the Preen product that is labeled for use around the asparagus and use it in combination with the mulch to help with annual weeds. Pay close attention to the label on the Preen product, it states it can only be used in the early spring before spears emerge.
Harvesting
Harvesting can be completed by cutting or snapping spears off the plant as they emerge and grow to 5-8 inches in length. Harvest for 6-8 weeks or until the majority of the spears are less than 3/8 inches in diameter. When all the spears get spindly, the plant is running out of energy for production and harvest should be concluded to allow the plant to rebuild its resources for next year.
*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.
If you have any further questions please contact Nicole Stoner at (402) 223-1384, nstoner2@unl.edu, visit the Gage County Extension website at www.gage.unl.edu, or like my facebook page at http://www.facebook.com/NicoleStonerHorticulture and follow me on twitter @Nikki_Stoner
Nicole Stoner
Extension Educator
Gage County
March 2024