Asparagus Growing is Easy with Compost or Manure and Water

Q. My asparagus attempt resulted in five out of 10 crowns dying.  I did as you suggested and dug down as deep as my tiller would dig about 13".  For better drainage I drilled holes another 12" deeper and filled them with gravel. I ordered Jersey Knight asparagus and planted as per their instructions as well.

'Purple Passion' asparagus has purple stems which turn green when cooked. To get long straight spears requires plenty of nutrients, water and cool temps starting to warm up.

Asparagus planting done in late fall or very early spring with amended soil with compost or aged manure. Drip irrigation can be used but watering should follow a similar pattern to watering fruit trees.

A. The usual reason for asparagus dying or growing poorly after planting is because the plants are watered too often, and the crown or roots drown. Asparagus must be planted in soils that don’t hold water. If the soil holds water easily or there is poor drainage then consider planting asparagus crowns just below the surface of the soil and mound the soil eight or 10 inches above it. Mounding the soil provides better drainage in heavier soil.

Asparagus crowns like this one can give you 100% male plants which produce higher yields. Taste is the same.

            Don’t water deep rooted asparagus the same as other annual vegetables. They could be watered with other perennial vegetables such as artichokes or even fruit trees or landscape trees and shrubs! If in doubt, use a soil moisture meter with the tip inserted at about 4 to 6 inches deep in the soil. Never trust a dry soil surface to tell you if the soil where the roots are growing is dry or wet. Water again when the average needle measurements register midway or around “5” on the moisture gauge.

Asparagus can be started from seed but its better if grown from crowns. Seed results in a 50/50 stand of male and female plants. Female plants are not the heavy producers that male plants can be.

            Asparagus grows in the wild near the edges of irrigation ditches in the desert. But not in the ditch. This means they like to get their “toes” occasionally wet but not submerged. These locations are similar where palm and fig trees like to grow. I had good luck growing asparagus between fruit trees when they were young and there is enough light. When fruit trees get older and dense, it is more difficult to grow asparagus because there is less light. Move the crowns to new locations during the winter months where there is moisture and adequate light.

If the winter is not cold enough to kill asparagus tops then cut them back, turn off the water for a month and resume production.

            Adding rock beneath the crowns doesn’t help drainage at all. It’s the same story with sand. To get any kind of soil improvement requires additions of 80 to 90% sand above and below where the plant roots are growing. Research has not looked at gravel but I assume it is the same. But additions of rock above the crowns cause them grow crooked spears. Straight spears require soil above the crowns without rocks.

            In my trials over the years, all varieties of asparagus (12 different varieties) produced spears but the longest and most saleable spears were produced by UC151 hybrids bred by the University of California in Riverside for the hot, dry desert. All the “Jersey” varieties, bred by Rutgers University (New Jersey), didn’t yield as well in the Mojave Desert. You get quality spears with other varieties, but the spears must be harvested earlier than UC151 and this makes them shorter. This holds true for old-fashioned varieties like Martha Washington and most purple types.

            I fertilize asparagus in midwinter with a layer of manure or compost applied once a year and watered in. You can also use a high nitrogen fertilizer, but it will not improve the soil like manure or compost does.