Asparagus is spring’s most luxurious vegetable. It was once cultivated for medicinal purposes as a natural remedy for blood cleansing and diuretic properties. During the Renaissance, asparagus was also promoted as an aphrodisiac and banned from the tables of most nunneries. Botanically, asparagus is a member of the lily family, closely related to onions and leeks, though it bears no resemblance to them in appearance or flavour. It is a finicky plant, harvested by hand and requiring much attention during the brief growing season. Left to mature it will sprout into beautiful feathery ferns that are often used in floral arrangements. Asparagus is a hardy perennial. It is the only common vegetable that grows wild along roadsides and railroad tracks over a large part of the country. Although establishing a good asparagus bed requires considerable work, your efforts will be rewarded. A well-planned bed can last from 20 to 30 years. For this reason, asparagus should be planted at the side or end of the garden, where it will not be disturbed by normal garden cultivation.
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 do not have a weedy seedling problem. A line that produces only male plants was discovered and has been incorporated into some truly amazing varieties. Jersey Giant, Jersey Knight, Jersey Prince, and Viking KBC, are new hybrids with larger yields. It is advisable to plant the best variety available, as an asparagus bed should remain productive for at least fifteen to twenty years. If you are starting a new bed, you may never get to choose a variety again if your bed produces that long. All the newer varieties are cold tolerant and are resistant to rust and fusarium.
Asparagus should be planted as soon as the ground can be worked in the spring. One-year-old crowns or plants are preferred. These young plants should have compact buds in the center (crown), with numerous dangling, pencil-sized roots when they are ready to plant. Place the plants (or sprinkle the seeds) in a trench thirty to forty-five centimetres wide and a full fifteen centimetres deep. The crowns should be spaced twenty to thirty centimetres apart. Spread the roots out uniformly, with the crown bud side up, in an upright, centered position, slightly higher than the roots. Cover the crown with two inches of soil. Gradually fill the remaining portion of the trench during the first summer as the plants grow taller. Asparagus has a tendency to “rise” as the plants mature, the crowns gradually growing closer to the soil surface.
As asparagus plants grow, they produce a mat of roots that spreads horizontally rather than vertically. In the first year, the top growth is spindly. As the plants become older, the stems become larger in diameter. Because asparagus remains in place for years, advance soil preparation helps increase future production greatly. Working green manure crops, compost, manure, or other organic materials into the proposed bed well in advance of planting is a good approach. Asparagus should be fertilized in the same way as the rest of the garden in the first three years.
Asparagus can be harvested the third year after planting crowns, but for no more than one month the first season. The plant is still expanding its root storage system and excessive removal of spears weakens the plants. During the fourth year and thereafter, the spears may be harvested. If you planted seeds, you may need to wait up to five or six years before you can begin harvest. Be aware that pencil thin or thick stems can be equally delicious and contrary to popular belief, thinner stems are not an indication of tenderness. Thick stems are already thick (often male plants) when they poke their heads out of the soil and thin stems do not get thicker with age. Tenderness is related to maturity and freshness.
Although it takes a few years to reap the fruits of your labour when establishing an asparagus patch it is well worth the time and effort down the road, as you will enjoy the fresh flavour of asparagus for decades into the future.