Kelly Jackson
Christian County Extension Office
Grow Delicious Asparagus in Your Garden
Asparagus is low in calories and provides substantial amounts of two antioxidants—vitamin A and C. It’s a great source of folate and has a goodly amount of fiber. Best of all, you can grow your own with just a little garden space, lots of patience, and the right information.
Now is the time to plan for an asparagus bed and to order crowns for planting in the spring. When starting an asparagus bed, select a location at the edge of the garden where it will not be disturbed. Asparagus is a perennial and therefore will remain in the same location for 15 to 30 years. For best results, avoid a low, poorly drained or shaded site.
To prepare the soil for planting, incorporate organic matter such as well-rotted manure or compost into the soil to a depth of 8 to 12 inches. Organic matter improves the physical condition of the soil and makes it a better growing environment for the asparagus plant.
It is recommended to start with one-year-old crowns. Asparagus plants are naturally either male or female. The female plants bear seeds, which take considerable energy from the plant and sprout new seedlings, which cause overcrowding in the bed. Male plants produce thicker, larger spears because they put no energy into seeds and have no weedy seedling problem. Top varieties include Jersey Giant, Jersey Knight, and Jersey Prince. All the newer varieties are cold tolerant and are resistant to rust and fusarium.
The crown of an asparagus plant is a combination of fleshy and fibrous roots and rhizomes, which are underground stems with buds. The fleshy roots store food reserves that help develop tender shoots the next spring. Dormant crowns should be planted in early March to early April. Usually they are planted in a trench 12 to 15 inches wide and 6 to 8 inches deep. Plant at the shallower depth if the soil is heavy clay. Make sure the organic matter and fertilizer have been incorporated before setting the crowns because organic matter cannot be added later.
Set plants 15 to 18 inches apart with 30 inches between rows. Approximately 10 to 15 plants will produce enough asparagus for one person. Place the crown on a small amount of soil in the trench, allowing it to be slightly higher than the roots. Spread the roots out and cover the crown with 2 to 3 inches of soil. Firm the soil gently over the crown. As shoots begin to grow, continue to put soil around and over the crown. Repeat this procedure as the plant grows until the trench is filled. Mulching around the asparagus plants with 3 inches of mulch, such as weed-free straw, will help to control weeds.
Asparagus shoots or spears should not be harvested the first year after crowns are set. The shoots are needed to supply food to the root system and to store food for the next growing season. The second year after planting, limit the harvests to three to four weeks. Then let the shoots grow. Again, the root system needs to continue to develop. Plants harvested too heavily and too early after setting may become weakened and spindly. The third year after planting, harvests can continue for 8 to 10 weeks. The harvest may end earlier if numerous spears pencil-sized or smaller are produced. Allow the shoots to grow all summer to transfer food to the roots.
Early in the spring each year, before the spears appear, sidedress asparagus plants with 1 pound of 5-10-10 fertilizer per 100 square feet. To sidedress asparagus, place the fertilizer in bands about 6 inches away from the plant on both sides of the row and gently rake it into the soil.
