Pruning Asparagus

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.

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23 Responses to Pruning Asparagus

  1. Mark Hoy Jr. says:

    Very , very helpful. Thanks a million

  2. Linda Morgan says:

    This is the second year for my asparagus and I did not harvest. I’d like to cut them back now though because they all got bent over in a storm, they didn’t break. I can’t seem to get them to stay upright now even with support. Any reason not to cut them?

    • Christy says:

      Yes, there is a reason not to cut them. Asparagus is like a flower bulb in the way that it stores up energy for the next year. Those fronds are gathering nutrients and energy for next year’s fruiting. Leave them there until they turn brown, then you can cut them down if you wish. I leave mine over winter because the lady bugs use it as habitat, then I cut it down in early spring. Either way, if you cut them while still green you will greatly reduce their potential for next year.

  3. Loann says:

    We live in the country of Panama…in our new home there is a really nice garden with some very tall asparagus fronds – please, tell me what to do and I will do it!

    • Christy says:

      HI Loann,

      The first thing to do is make sure it is the edible kind of asparagus, rather than asparagus fern. Asparagus fern is an invasive plant that will take over your yard if you let it. I’d get that out of there if it’s not edible. If you’ve verified that you have edible asparagus, let the fronds grow until fall, and you can cut them down when they turn brown and dry out. Some people leave them through winter and cut them in early spring because they can provide habitat for lady bugs and other beneficial insects. Cut the fronds down to the soil level in spring (or winter, really) and then amend the bed in early spring for new growth. That’s about it.

  4. Donald Adams says:

    You should pick the red seeds and not let them sprout the following season. More plants will crowd out what you have already planted and current plants will not produce as much.

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