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How do I grow asparagus?
How do I grow asparagus?
Few harvests from the vegetable garden have a greater anticipation than when it comes time for asparagus. If you have some space in the yard in full sun and out of the way of other routine gardening activities, you may want to try your hand at establishing a bed. The rewards take some time to realize, but an asparagus bed can give 20 to 30 years or more of productive harvest provided good weed control and fertility. Early spring is the best time to plant.
Asparagus is a herbaceous perennial whose root system continues to grow each year to expand the production of immature edible shoots which develop from a crown buried in the soil. There are basically two ways to start an asparagus bed. If you start from seed planted in a bed, plants will not produce well until the third growing season. You can reduce this by one year by planting one-year old roots purchased from local garden centers or ordered from nursery catalogs. They will come as a mass of sprawling, skinny roots with a center full of buds (crown). Do not start from older root stock. This has proven to delay production.
The heralded breakthrough in asparagus production recently was with the development of all-male hybrids. Male plants are touted to live longer and yield higher than females. This is because female plants spend energy on forming flowers and setting seeds taking away from energy reserves directed to the roots. The other advantage of all-male plants is that you avoid self- seeding. Young plants randomly sprouting from seed can be a real problem. All-male plants, of course, avoid this problem. The most widely planted variety of asparagus for decades has been 'Mary Washington.' The most common of the new all-male selections are teh 'Jersey' hybrids, including 'Jersey Giant', 'Jersey Centennial,' Jersey Prince,' and 'Jersey Knight.'
As soon as the soil can be worked, dig a trench 12 inches wide by 12 inches deep. Remove the soil and mix with one part leaf mold or compost with two parts soil plus 2 pounds of 10-10-10 per 100 foot of row. Fill the trench to within 6 inches of the top and level off. Spread the root system of each plant out in the trench spacing individual plants about 2 feet apart. Fill over the crown with 2 inches of soil mix. As the shoots emerge, add soil until the planting site is filled. If done this way, the plants will not be smothered.
As the shoots begin to emerge in the first season, mulch the plants with several inches of leaf mold or compost. Do not disturb these plants or cut the tops. Let the fern-like leaves grow all season to supply nutrients to the root system. Cut them back to the ground the next spring. In the second year, fertilize the bed with 1.5 pounds of 10-10-10 per 100 feet of row in mid-March. Some spears can be harvested in the second year, but this crop is likely to be light because the root system has not become fully established. In a warm climate like ours, harvesting the spears will stimulate bud formation and improve future yields. In the third year, again fertilize in the spring as before. This crop of spears should be quite abundant. When the number of shoots begins to thin out, you will know that it is time to let the tops grow out. By the fourth year, the bed should be well established. Delay fertilization until harvest is over and use the same amount of fertilizer as previously noted for spring treatments.
The bed should continue to increase its production for 7 or 8 years then level off. To get the highest yield, harvest spears when they are 6 to 8 inches long. This is done by snapping them off at or just above the soil line. Some recommend cutting below the soil surface, however, this can injure shoots which have not yet emerged. The harvest schedule will vary. Generally, the younger the spears, the better the flavor so be aggressive.