Frost damage in asparagus
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
When moderate frost settles on emerged asparagus spears, they often remain erect and appear to be normal for a few days. A hard frost normally turns spears to mush and they fall over and disintegrate. The day after the frost the spears can be harvested and eaten, but frosted spears should not enter processing or fresh trade. By the second day, the color turns dark green and the tips become corky and brittle. The spears may even elongate an inch or two. After the second day after the frost, the spears are not usable and they begin to shrivel and slowly turn brown.
Frozen spears that remain standing in the field appear to have an adverse effect on the plant, and new spear production is reduced for several days. The effect can last a week or more. The most effective management of a frosted field is to snap off all frosted spears as soon as possible. If a field was entirely frosted or frozen, the simplest method for removing spears is to mow the field. If only spots or individual plants are affected (which is quite common, for some strange reason), have pickers snap off the darkened and bent spears and leave them lying in the field, while harvesting the good spears.
With the forecast for possible frost this weekend, growers should have a plan ready for removal of frosted spears. Remove them the day after the frost, if possible, to return to normal production.
Dr. Zandstra’s work is funded in part by MSU‘s AgBioResearch.