By Aaron J. Steil–Iowa State University Extension and Outreach

What is a suitable planting site?

Grow asparagus, rhubarb, and horseradish in moist, well-drained soils. Rhubarb prefers highly organic soils, and horseradish is better grown in low-fertility soils to help control its rapid growth rate. Avoid poorly drained, wet sites. Heavy, clay soils can often be improved by incorporating organic matter, such as compost or well-rotted manure, into the upper 12 to 15 inches of soil. Raised beds are also a good planting option for sites with poorly drained soils.

Start with a weed free planting area. The planting site should receive at least six to eight hours of direct sun each day.

What is the proper way to plant asparagus? 

Early spring is the best time to plant asparagus. Asparagus crowns should be planted in shallow trenches. The planting depth depends on the soil type. Asparagus crowns should be planted eight to 10 inches deep in light, sandy soils, but only 6 to 8 inches deep in heavier soils. A small amount of compost or well-composted manure can be worked into the soil at the bottom of the trench before planting. Space crowns 12 to 18 inches apart in rows that are 4 to 5 feet apart. Then, spread the roots out in the trench with the buds pointing upward. After planting, completely fill in the trench with soil.

What is the proper way to plant rhubarb?

Spring is the best time to plant rhubarb. Space individual plants three feet apart. Plants growing in containers should be planted at the same depth as they are currently growing in their pots. Bare-root plants should be planted with the buds one to two inches below the soil surface.

What is the proper way to plant horseradish?

Early spring is the best time to plant horseradish. Grow in an area where its spread can be contained. Loosen the soil down eight to 12 inches and incorporate a small amount of compost or well-composted manure. One to three plants spaced 12 to 18 inches apart is all that is necessary to produce enough horseradish for the typical home. Plants growing in containers are planted at the same depth as they are growing in the pot. Often, horseradish is sold as root cuttings. Dig a hole or trench and set root cuttings at a 45-degree angle with the slanted-cut side down, then backfill with soil. The top of the cutting should be one to two inches below the soil surface when done.

When can I start harvesting newly planted perennial vegetables?

Do not harvest asparagus or rhubarb for the first two years after planting. In the third and following years, asparagus can be harvested until early to mid-June. Harvest rhubarb lightly in the third year, only collecting stalks for four weeks. In the fourth and succeeding years, rhubarb stalks can be harvested for eight to 10 weeks. Horseradish is typically harvested in the late fall after the first frost of the season. Do not harvest horseradish roots the first year. Begin harvesting horseradish annually the following fall.