Asparagus was first cultivated by the Romans, who used it for food and medicinal purposes. It was brought to America by the early colonists.

The asparagus bed in the Kew Gardens, London, England, is still producing after about 150 years. The key to its longevity is the diligent soil preparation and maintenance it receives. Home gardeners can expect up to a 25-year life span of their asparagus bed if it is well prepared and maintained.

The bed should be prepared on well-drained soil in full sun. Dig trenches 18 inches wide by 10 inches deep. Mix the soil removed from the trench with an equal part of compost, peat moss or mushroom manure. Add 3 to 4 inches of the mixed soil to the bottom of the trench before planting the root.

One-year old roots, not two-year old roots, should be purchased. Spread out the roots like an octopus, crown side up and plant at 2-foot intervals. Cover the roots with 2 inches of soil mix. If the roots are dry when purchased, soak in water overnight. Once the roots begin to grow gradually, add more soil mix until the trench is full.

Asparagus is a heavy feeder and requires routine applications of fertilizer. The first year, apply 3 pounds of a 5-10-10 fertilizer per 50 feet of bed in July. During early spring of the second and subsequent springs, apply 1 pound 5-10-10 per 50 feet of bed and a second application of 1 pound of 5-10-10 in July.

Newly planted roots require considerable water. Water sufficiently to wet the soil 10 inches deep. After the first season, asparagus plants do not require frequent irrigation because of the deep and extensive root system. During dry periods, slowly soak the bed with 2 inches of water every two weeks.

Asparagus should be planted on the north or east side of the garden because asparagus ferns grow 5 feet to 6 feet high and would shade other plants. It is essential that these tall-growing ferns (brush) are not removed until spring at the time when asparagus emerges from the soil. The brush absorbs sunlight and photosynthesis produces energy in the root system. Removal of the brush can substantially hinder the following year's crop.

Do not harvest any spikes until the third spring. This is necessary to allow the plants to develop an adequate storage root system. A general rule for harvesting is the 2-4-6 sequence. Harvest for two weeks the third year, four weeks the fourth year, and six weeks the fifth and following years.

There are five varieties of asparagus recommended for Pennsylvania. These are Jersey Jewel, Jersey General, Jersey Giant, Jersey King and Jersey Knight. All varieties except Jersey Jewel are resistant to rust and fusarium root rot. These are the two most common diseases of asparagus.

The most damaging insect is the asparagus beetle. Adult beetles look like lady bird beetles. These beetles lay rows of black, elongated eggs on asparagus brush. The larvae do the damage by eating the brush. They can be controlled by spraying with Bt in the fall.

When harvesting, it is best to break off spears rather than cutting them. If the crop cannot be consumed the day it is picked, place the cut ends in a shallow pan of water and immediately place in the refrigerator. Good quality can be maintained for several days when refrigerated.

Weight conscience gardeners should note that a 2 oz. (60 gram) serving of asparagus contains 10 calories, 1 gram protein, 2 grams of carbohydrates and only traces of fat.