Perennials: What not to cut back in Fall

Posted on October 31st, 2018

Nothing says fall is fully here like realizing that mornings start with a frosty car and cranking the heat to get the windows clear. Unfortunately for your plants, there’s no heater to keep them warm, and right about now, your perennials are probably looking pretty sad. If you’re like many gardeners, that means it’s time to hack everything back! Well, maybe not. If you have any of these perennials listed below, you’ll want to avoid cutting them to the ground this fall, or in some cases, cutting them back at all.

  • Lavender– Wait until March! Cut out any dead wood at the end of winter to ensure the best new flush for your lavender plants.
  • Montauk Daisy (Nipponanthemum)- Cut this woody perennial back to six inches from the ground this fall.
  • Russian Sage (Perovskia)- If the shape or health of the plant has been compromised, cut it back aggressively this fall, to roughly six inches. If not, leave it alone until early to mid-spring, removing any dead wood and cutting back to where you see new growth emerging. Remember- it’s a late breaking plant, so give your sage a little extra time to start growing.
  • Geum– Remove any damaged or dead foliage now, leaving the majority of the plant for the winter. You can repeat this process in April, removing any leaves with winter injury, and even divide it in April and early May every three to four years, but if you need to cut it all the way back, wait until after Geum flowers. 
  • Perennial Hibiscus– Cut this plant back to about six inches from the ground this fall- not because it will grow from the stump, but to keep a marker for you to remember you have this plant. Perennial hibiscus won’t be back in your garden until at least June!
  • Summer and Fall blooming Clematis– Wait until spring to clean up any dead wood on these plants, once you start seeing a little new growth. 
  • Ornamental Grasses– Keep these around all winter to protect the bases of the plants, where the new growth will emerge in spring. Don’t cut them back until March at the earliest, or April at the latest. 

Will O’Hara

Perennial Manager