A question came in to Ask Gardenerd this week:
you please help me understand how to trim my 4’ tall asparagus patch
that was planted in the fall? Does it need to turn completely brown? How
low do I trim it?“
Great question, and the answer can be confusing, because there are two schools of thought on the matter. Many gardeners, including those at Peaceful Valley Farm and Garden Supply (here’s their video), recommend cutting asparagus back in the late fall and mulching with straw to protect the plants from frost. This can help prevent the crowns from rotting from fungi that develop on the plant over winter. Some say to cut back the fronds at soil level, other say to cut them about 1 inch above the soil.
On the flip side of the coin, there are gardeners and farmers who leave their foliage until spring. Much like bulbs, those fronds are collecting nutrients for next years production. There are farmers who also claim that the existing foliage will tent snowfall (if you have that) and insulate the plant from frost damage. My own personal pruning preferences reside on this side of the coin.
One of our asparagus beds in late fall. Partially brown, not yet ready to cut back
There’s a reason why I leave the foliage until spring: habitat.
About 3 years ago, when I first planted asparagus, I noticed in late summer and early fall that ladybugs would “move in” to the asparagus patch to mate and lay their young. The benefits were obvious. Ladybug larvae eat about 400 aphids in a couple weeks, meaning my garden would be practically aphid-free by the end of their visit.
Just one of hundreds of lady beetles that makes our asparagus patch home for the winter
Behind the dead asparagus fronds is a renegade tomato plant.
This year our lady beetles have more to munch on. Our renegade tomato plant volunteer from summer is still producing, but is beginning to be covered with aphids. The lady beetles are taking swift action, enjoying themselves immensely.
So in the spring, I will cut down my asparagus foliage, and layer about 1 inch of compost in each bed. That will give them the signal that it’s time to start producing. Over winter, I still water occasionally, but much less often. In snowy conditions you wouldn’t do this, of course.
I hope this helps. Thanks for your questions – keep writing in.
Hey gardenerds, what do you do with your asparagus? Share your experiences with us here.