cutting back aspargus

Asked June 20, 2019, 12:52 PM EDT

when is it ok to cut back the asparagus plant? Do I need to wait until after the first frost? They have gotten to HUGE and are taking over the area.....thanks!

Multnomah County Oregon

1 Response

Hi, and thank you for contacting Ask an Expert in regards to when to cut back your asparagus. The fern creates energy that will be stored in the underground portion of the plant to produce the following year’s spears. It is important to take care of the ferns even after the harvest is over to make sure you will have good future harvests.

The proper time to cut down asparagus ferns is during their dormant period. The process of becoming dormant is turning from the chlorophyll-green color that typifies photosynthesizing plants to a bright, vivid yellow. The loss of green pigment signifies that these plants are no longer photosynthesizing, but does not indicate full dormancy. That state has only been reached when the fern turns the same light brown color that one sees on dormant pastures or mature cornfields. Asparagus fern can be mowed or chopped any time after the “dormant brown” color is seen without losing any of the energy that will go into making next year’s spear crop.

Again, thank you for contacting the Cooperative Extension Ask an Expert and happy gardening.