Asparagus: Crowned King of Garden

May 15, 2004

By Mary Giambalvo, Master Gardener


As the grandchild of farmers, I have an inherent fondness for garden plants that pay their own way, so to speak. Asparagus stands out because it rewards us with terrific meals and good looks for years and years with minimal labor on my part.

My garden journal tells me that my asparagus plants are in their twelfth year of prodigious production here on the
Central Coast. If you donít count the daily harvesting, Iíve spent less than fifteen mornings of hard labor in more than one decade. There were a few days twelve years ago spent preparing the bed and planting the crowns and one autumn day each subsequent year putting it to sleep for the winter. Automatic watering saves additional time. Nothing else I grow takes as little effort for the rewards it gives.

Location is particularly important because, like fruit trees, asparagus expects to stay around for a good while. It likes to grow in deep, sandy loam, but it will tolerate heavier soil if it drains well and the water table is at least four feet below the surface. Although asparagus prefers areas that develop low enough temperatures to put it to sleep in winter, I am successfully growing it on the coast with very little chill.

One-year-old asparagus crowns can be ordered in the winter for spring delivery. I have done well with UC157 and Jersey King, but almost every year there are new hybrid varieties released with improved qualities.

It pays to spend time preparing the bed. Make a trench six to ten inches deep, 12 inches wide, and four to five feet apart if you want more than one row. Mix in some rich compost. Settle the crowns about a foot apart in the trench, splaying out the roots. Cover the crowns with more compost and soil and give them a good watering. During the next week as the crowns start to sprout upward, keep watering and filling in the trench with compost and good soil. Continue until the trench is level with surrounding soil. That completes the hard work except for periodic watering. You donít, however, get to eat any for at least a year.

As spring turns into summer, the spears will grow into tall beautiful fronds of fern. This is the time it stores its nutrients for the following yearís growth. Meanwhile, it makes a lovely backdrop for colorful shrubs for the entire summer and into autumn. In areas where the weather gets cold, the asparagus will turn brown in fall. This is the cue to cut it to the ground. On the coast, most of my ferns will not die so I arbitrarily cut them back soon after Thanksgiving. A substantial new layer of compost and mulch will stave off weeds, keep the bare ground looking good the rest of the year and provide nutrients.

At the one year anniversary it is best to avoid harvesting. This allows the asparagus to get a foothold in its new home. Well, okay, take a little because you wonít be able to resist. Next year will bring a longer harvest. By the third year and thereafter, the asparagus will provide good eating for two to three months.

When you grow your own, you will learn to love those fat, tender spears heaving up from the soil. There is a common myth that thin asparagus is more desirable than fat asparagus. In truth, when the spears get slender and spindly, the asparagus is tired and ready to rest. Stop harvesting and give it a vacation until next spring.

Whether oneís own roots are agrarian or urban, there is a natural desire to eat well and to not work too hard for it. Asparagus makes the cut on both counts.

University of California Cooperative Extension Master Gardener Volunteers can provide additional gardening information upon request. Call the San Luis Obispo office at 781-5939 on Mondays and Thursdays from 1 to 5 PM, the Arroyo Grande office at 473-7190 on Wednesdays from 9 AM to 1 PM, or the Paso Robles office at 237-3100 on Wednesdays from 9 AM to Noon.  The San Luis Obispo Master Gardener website is at Questions can be e-mailed to