Spring has finally arrived and one of its first harbingers in our area is the appearance of asparagus spears shooting up from an established bed.
Although somewhat labor- intensive to start, a well-maintained asparagus bed can provide your family with a dependable spring harvest for many years. Since asparagus is an excellent source of several vitamins, it deserves special consideration by the home-gardening enthusiast.

The preferred method for establishing a bed is to use 1-year-old dormant crowns, which are readily available from garden-supply catalogs and local nurseries. Choose varieties that are rust and fusarium wilt-resistant like Jersey Giant, Jersey Centennial, Jersey King or Jersey Knight. The "Jersey" series of asparagus, developed by Rutgers University researchers, are highly productive, all-male hybrids and grow well in our region. You can plant asparagus seeds but it will take an extra year to produce a harvest.

Each mature asparagus plant will produce 15 to 20 shoots per year. Unless you plan on canning or freezing extras, a mature bed with 12 to 18 plants should provide more than enough asparagus for a family of four.

As with all perennial plantings, proper site selection is critical Asparagus prefers deep, sandy loam and requires a well-drained site in full sun. You may want to consider an area somewhat separate from your existing garden so the bed will not be disturbed by the annual tilling required for your garden plants. In addition, the, tall ferns of mature asparagus may shade other plants near the bed so plan accordingly.

Since deep, sandy loam is in short supply in our area, adequate soil preparation is a key component for a successful asparagus bed. This is where the labor-intensive part begins. Start by removing all grass and weeds in the desired area. Asparagus is a moderate to heavy feeder, so prepare the bed in advance enriching it with compost, well-rotted manure, leaf mold or a combination of these.

Then dig a trench 10 to 12 inches deep and, about 12 to 18 inches wide. If multiple trenches are desired they should be spaced four to five feet apart. In heavy soils like ours, double digging is recommended. To accomplish this, break up the subsoil in the trench by pushing your spade into the next 10 to 12 inches of soil and rocking it back in forth; do this every six inches for the length of the trench. Keep all the excavated soil next to your trenches; you will be using it to fill in the rows as the asparagus grows. " Once the trench has been dug, sprinkle in a complete fertilizer that is high in phosphorus and potassium (for example a 5-10-10 formula) to encourage vigorous root growth. Asparagus also requires a neutral soil, so add line if your soil pH is 6.0 or below. Finally, apply a 2- to 3-inch layer of compost or well-rotted manure and incorporate all amendments into the bottom of the trench. A small rototiller can make this task more appealing. Next, create small mounds of soil spaced 15 to 18 inches apart inside the trench.

At long last, you are ready to plant the crowns. Place one asparagus crown on top of each mound of soil in the trench. Crowns should be grayish-brown in color, plump and healthy looking. The buds should face up and the roots should be spread out over the mound and into the trench. Cover the crowns with two to three inches of soil mixed with compost; firm the soil and water well. As the first shoots appear and continue to grow, fill in the trench gradually with the rest of the soil alternating with layers of compost. Once the trench has been filled in, cover the area with a 2-inch layer of straw mulch to help keep moisture in and weeds to a minimum.

During the first summer, allow: all the shoots to produce their lovely fern-like foliage. Do not harvest any spears this first year. Provide one inch of water per week when there is inadequate rainfall. Allow the foliage to stand until after the first hard frost, then cut back to 2-inch stubs when it starts to yellow.

A light harvest of spears over a three- to four-week period may be taken in the spring following planting but you should allow most shoots to mature into foliage. Harvest the asparagus when they are 6 to 8 inches tall and snap or cut off just below the soil surface, being careful not to injure the crowns. In the following years, a full harvest may be taken each spring, however, if spears becoming thin and spindly, stop harvesting immediately and allow the plants to produce foliage for future crops.

Maintain your bed by applying nitrogen in late winter and a top, dressing of compost each spring. Mulch with four to five inches of straw or shredded leaves each fall, which should be pulled aside in early April to allow the shoots to appear.

With a little patience and hard work, you will be rewarded with a bountiful harvest of these delicious green delights for many: years to come.

Melanie Bernier of State College has a bachelor of science degree in horticulture from Penn State.
For answers to your gardening questions, contact Master Gardeners by e-mail at centreext@psu.edu