emerging aspargus that keeps freezing this spring
We planted asparagus crowns last spring and they grew well and looked like a fern bed in the fall. We have been checking them for the last week and have found spears, but they have all been limp from freezing before we can harvest a single one! Will this ruin the entire plants in the bed? Should we cover them or when the nightly temps warm back up to a more constant range, will they grow so we can do a light harvest this year? What should we be doing? HELP
Olmsted County Minnesota
Thank you for the question. Asparagus spears are susceptible to freezing. The stalks probably emerged during the recent warm weather but then last week, if your County was like the Twin Cities, we had night temperatures in the mid to high 20's. It's possible the spears froze during the weather last week. A way to avoid this is to make sure you planted the crowns deep enough last year. Crowns should be planted about 6-8 inches deep. If planted too shallow they will emerge earlier than they should because the top layers of soil warm up to 50 degrees and stimulates growth. The shoots can then freeze during nighttime freezing temperatures. Another technique to help premature emergence and freezing is to mulch the asparagus bed in the fall with chopped leaves, or whatever you commonly use.
I don't know if your asparagus crowns are dead but I would guess not since the soil acts as an insulator. We suggest watching the night time weather reports and covering your asparagus bed with something like old bed sheets held down rocks, bricks, or similar item to keep the cold night air from creeping under the cover protector. During the daytime, remove the cover. You may get a few spears to harvest this year, but next year will be better now that you know you need to watch for frost.
Read more about growing asparagus in the home garden: http://www.extension.umn.edu/garden/yard-garden/vegetables/growing-asparagus-in-minnesota-home-gardens/
Good luck and thank you for contacting Extension.