An asparagus planting may be productive for 15 to 20 years when good cultural practices are followed.
The first chore in the spring is to cut off the dead asparagus foliage at ground level. Early spring is also an excellent time to fertilize the asparagus planting. Apply 50 pounds of barnyard manure per 100 square feet. Lightly till the manure into the top 2 or 3 inches of soil with a rototiller or spade. This must be done in early spring before the asparagus starts to grow. If manure is unavailable, apply 1 pound of a balanced garden fertilizer, such as 10-10-10, per 100 square feet in the spring.
Weed control efforts in the spring are also important. The best way to control annual weeds is to periodically hoe or till the planting. Cultivate lightly to avoid damage to the emerging spears. Home gardeners also have the option of applying the preemergence herbicide Preen. Established perennial weeds, such as quackgrass, can be effectively controlled by applying Roundup (glyphosate) to the weeds immediately after the last harvest of the season.
Begin harvesting the asparagus spears when they are 6 to 8 inches long. Harvest by cutting or snapping the spears at ground level. Stop harvesting an established asparagus planting by early to mid-June.
This article originally appeared in the March 27, 1998 issue, p. 27.