Don’t Cut Those Asparagus Ferns Yet!
As the weather cools and your asparagus ferns start to fade, it’s tempting to tidy up the fields and cut them down. Resist that urge. Cutting asparagus ferns too early is one of the most common mistakes growers make, and it can cost you next year’s harvest.
Why Asparagus Ferns Matter
An asparagus bed is typically considered established about three years after planting. Once established, you can harvest spears for roughly 6–8 weeks each spring. When the harvest ends, the remaining spears grow into tall stalks with fine, feathery foliage known as ferns.
These ferns aren’t just decorative; they’re the plant’s energy factory. All summer long, the ferns photosynthesize and send carbohydrates down to the crown, rebuilding the reserves the plant used up during spring harvest. A healthy, vigorous stand of ferns this year means a bigger, better crop of spears next spring.
That’s also why it’s important to stop harvesting after the 6–8 week window: picking spears all summer prevents ferns from forming and starves the crown of the energy it needs.
What Happens in Fall
As temperatures drop, your asparagus ferns will gradually turn yellow, then golden, and finally brown as the plants head into dormancy. This color change signals that important work is still underway.
During this transition, the plants are moving sugars from the ferns down into the roots, where they’re stored as energy for next year’s growth. That process isn’t finished until the plants are fully dormant and the stems have turned completely brown. Cut them while they’re still green or yellow, and you interrupt the plant’s winter preparation.
When to Cut Asparagus Ferns
We recommend waiting until the ferns are entirely brown and you’ve had several hard freezes. Then, you have two good options:
Late fall: Once the ferns are fully brown and dry, you can cut or mow them down to a few inches above the soil. This is the better choice if your bed has had problems with asparagus beetles or foliar diseases, since removing the old growth eliminates places where pests and disease can overwinter.
Early spring: Leaving the ferns standing through winter helps trap snow and insulate the crowns. Just be sure to cut them down before new spears begin emerging.
Whichever you choose, the key is the same: don’t cut too early!
Tip: Use Ferns as Mulch
If you wait until early spring to cut your ferns, you can chop them up and spread them over the bed as mulch to help suppress weeds.
Only use clean, healthy ferns for mulch. If your plants showed any signs of pests or disease, such as asparagus beetles or rust, remove the ferns from the garden and dispose of them rather than composting or mulching with them.
