Perennials: To cut or not to cut?
Oct 25, 2024, 6:00 AM
Cutting back perennials is the main topic of interest for gardeners in the fall. (Canva)
(Canva)
SALT LAKE CITY — Cutting back perennials is the main topic of interest for gardeners this time of year. The question most people ask is whether they should prune in the fall or spring.
According to KSL Greenhouse Host Taun Beddes, you can cut back about 90% of the perennials out there in the fall, but there are some that you should consider waiting for spring.
The first step to determining whether to prune is checking if the perennials are brown.
“You don’t want to cut them back when they’re still green because they’re actively growing and it could shock them,” Taun said. “You want to let them go dormant naturally and turn brown or let them get hit by hard frost.”
Perennials typically turn brown between late October and early November. When that time comes, you can cut them back within a couple of inches of the ground.
If you’ve already cut them down to the ground, there’s no need to worry because you’re not hurting them, Beddes said.
Perennials to consider keeping
There are some perennials that can remain untouched until the spring. These include grasses that add interest to the winter landscape due to their upright structure and their seed heads. Karl Foerster grass, feather reed grass, and miscanthus grass are a few examples.
One thing to keep in mind about leaving grasses is that they do leave a mess. Therefore, Beddes said he prefers to cut everything down in the fall so that he doesn’t have to clean it up in the spring.
Another reason to leave certain perennials in place is because they can be a source of food for birds in the winter. Take the daisy family, for example, such as black-eyed Susans, sunflowers, and coneflowers. These are also stiff enough to stand up to snow.
Perennials to cut back now
On the flip side, lilies and daylilies should definitely be cut back in the fall.
“They are very difficult to clean up if they’ve partially rotted up in the snow,” Beddes said.
Read more from the KSL Greenhouse show:
- When should you rake those autumn leaves?
- Got green tomatoes? Here’s how you can ripen them
- Getting your garden ready for next spring
KSL Greenhouse is on every Saturday from 8 a.m. to 11 a.m. Follow the show on Facebook, Instagram, YouTube, and on our website.
