Rejuvenate an Old Asparagus Bed

I was recently asked how to rejuvenate an old, neglected asparagus bed. Asparagus beds, if taken care of properly, can produce for fifteen or more years.

One of the biggest issues of poor producing asparagus beds is the competition for water and nutrients with weeds. Pull them, mow them off and/or spray them. Soft, moist soil after a rain makes pulling weeds much easier. If your preference is to mow the weeds, give them a shot of weed killer after doing so.  After you have gotten rid of the weeds, a layer of cardboard makes a great barrier in between rows. Lay a two to three inch layer of mulch, such as straw, over your asparagus bed to help keep the weed population down, conserve moisture and keep the soil cooler during the hot days of summer. Adding a layer of compost under the straw wouldn’t hurt. Do not apply salt as a way to kill weeds.  This may change the pH of the soil.

As the asparagus ferns out, female spears produce green berries that eventually turn red.

Over harvesting can be an issue also. Do not harvest spears that are less than three eighths of an inch. Leave these spears to fern out. This foliage is gathering food reserves for next years spear production. The ferned out tops should be allowed to remain as long as they are green. They will form a dense canopy that will shade out weeds. Tops that are left over the winter help to catch leaves and snow to insulate the crowns. If insects or disease have been a problem, it is best to remove the tops after they have turned brown.

Use an organic fertilizer in the early spring, before spears begin to emerge, to give plants a boost. Apply nitrogen after harvesting is finished to encourage foliage growth.

You can also fill in the gaps between old plants with some young, fresh roots. You will end up with a nice, solid bed in a few years.

As always, Happy Gardening!

More information about gardening and related subjects is available online at The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.