Is It Too Early to Plant Asparagus? What to Do Right Now for the Healthiest Harvest

One of the big bonuses of growing asparagus is that this nutrient-dense vegetable is a perennial plant you can harvest from for many years. However, you do need a little patience, as it takes time to mature, and it’s picky about planting time.

We asked the experts why planting asparagus in spring is the best strategy to allow you to appreciate fresh and flavorful spears year after year.

Why Spring Is the Best Time to Plant Asparagus

Shuresh Ghimire, Vegetable Associate Extension Educator for UConn Extension, says that asparagus plants establish best in early spring when the soil is cool and moist.

“Asparagus crowns or transplants should be planted as soon as the soil is workable, usually when temperatures reach around 50°F,” he says.

By doing this, Shruresh says it reduces the risk of frost damage, as the plants will be well-established before winter.  

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Why Is Fall Not as Good a Time to Plant Asparagus?

Planting asparagus in the fall is possible, but it’s a more risky proposition than spring planting. CSU Horticulture Extension Specialist Linda Langelo explains that cutting back the ferns to transplant the crowns too early in the fall shortens growth and stops the energy from returning to the root system.

This weakens the plant, making it more vulnerable to frost heave and freezing.  

If you have to transplant asparagus at this time of year, Langelo says that late fall is a better time.

“In late fall, the soil gets cooler, and the crowns are dormant as they are in spring,” she says. ”Dormancy is a prevention for transplant shock.” 

How to Plant and Grow Asparagus for the Healthiest Harvest

Even if you plant asparagus in spring, you need to provide the right conditions and care to provide the best chance of a bountiful harvest. Follow these tips for growing asparagus successfully.

• Depth: Long-lived asparagus develops deep roots, so it’s best to grow in trenches that are 8 inches deep. “Cover with 2 inches of soil initially, gradually filling as plants grow,” Ghimire says.
• Spacing: Plant crowns at least 12 inches apart in rows 4 to 5 feet apart. Ghimire explains this promotes good air circulation and helps to prevent disease.
• Light: Asparagus appreciates a full sun position where it gets at least eight hours of sunlight. “Shaded areas reduce spear production,” Ghimire warns.
• Soil: Asparagus plants do best in a well-drained, loose soil. Amending the soil with aged manure or compost improves drainage and fertility. 
• Water: “When you are first establishing an asparagus patch, give the plants consistent water of 1-2 inches per week,” Langelo recommends. She says you can reduce this to around every two weeks after the third season of growth and then every four weeks from the fourth season onwards.
• Mulch: “Grass clippings that have not been sprayed with lawn chemicals or fertilizer are a good mulch,“ Langelo says. Alternatively, you can use a layer of compost. Langelo explains that both of these options will help to suppress weeds. 

How to Grow Asparagus in Containers

When you have limited space or your soil has poor drainage, it is possible to grow asparagus in containers.

However, Ghimire cautions that it requires careful management due to the plant’s deep root system. He recommends using a pot at least 20 inches deep and wide to accommodate the roots, which can grow up to 6 feet deep. 

“Use well-draining potting soil with added perlite or sand,” Ghimire says. “Monitor soil moisture closely as containers dry out faster than garden beds.”