How to Grow Asparagus

Favored in Europe and in gourmet restaurants, white asparagus has a sweeter flavor than green asparagus. Though it’s a common misconception, white asparagus is not a variety of asparagus. It’s simply the manner in which it’s grown. Soil is heaped over the crown of the plant to prevent sunlight from prompting the production of the chlorophyll that makes the plant green. The spears are harvested in the early morning hours, just as the tips of the shoots break through the mounded soil.

Treat it right

When planting asparagus, bed preparation is essential and, ideally, should be done the year previous to planting; fall is an excellent time to begin preparation. Rich, fertile soil is not necessary. Remember, its native location was the sea coast, so asparagus prefers sandy, well-drained soil in full sun. It won’t mind growing in very sandy soil, but neither will it mind if you boost the organic matter in the soil with the addition of compost or manure. Asparagus roots are deep, so a well-drained location is crucial; it won’t tolerate heavy clay or soils that are continually wet.

A soil test should be performed before planting. Simple, easy-to-use soil test kits can be purchased from most nurseries, or contact your local county extension service for more extensive testing. Asparagus requires a neutral to high pH level (a “sweet” soil). Optimum pH is approximately 7.0 to 7.5, though a bit lower or higher is acceptable. If a soil test shows a low pH level, add garden lime in accordance with the package directions. Asparagus will grow in soils with lower pH levels, but research indicates that the lower levels promote the growth of Fusarium fungus, which attacks and eventually kills the plants.

Asparagus spears come from the crown of the plant. There are varied opinions about which is better to plant – the crown or seed. It’s thought that when planting from seed, diseases are less likely to be introduced into the bed. But the amount of time it takes a seed to grow to a crown mature enough to harvest from is lengthy, therefore asparagus is generally not directly seeded into the bed.

Most often one- or two-year-old crowns are planted – one-year crowns are preferable because they are less likely to suffer transplant shock than the larger, older crowns. Plant them 6 to 8 inches deep, leaving 2 to 4 feet between them to allow the ferns ample room to grow.

Don’t fill in the planting hole or trench completely. Cover the crowns with approximately 3 inches of soil, and water them in thoroughly. Using a root stimulant mixed in the water according to the package directions will help ensure the success of the new plantings by enhancing root development and reducing transplant shock. Wait about 6 weeks – enough time for the plants to sprout through the first 3 inches and start growing strong, then add another 3 inches of soil. When the plants go dormant in the fall, fill in the remainder of the furrow.