Perennial Plant Pruning

Through a moment of lazy logic I decided to defy conventional perennial pruning practice. Decided is the wrong word…perhaps forgot to would be better! I even posted about the proper way to take care of mums including pruning several weeks ago when the mums were fading. Did I do what I said? Nope, sure didn’t. Now I think that I did a good thing by not doing anything at all! Most people recommend that you trim back the mums to 3-5 inches in the fall after blooming. Not pruning them makes sense when you think about it. Mother nature knows best. Perennial plants in nature come back year after year with no one tending them, so why not do the same thing in the home landscape?

(a Salvia nemerosa with green growth at its base)

This was no great inspiration brought on to me through reading a book on perennials or an article in a newspaper. I was just too darn lazy to go out into the cold air to trim the dead growth off the plants. In fact I could have done it during our warm snap last week but by then I had decided not to bother with it. I think that trimming perennial plants before winter is mostly for aesthetics. Everyone wants their landscape to look great all the time but if you can stand to let go of the reins and let your plants do what nature intended you may benefit from it. I’m not advocating to never cut back your plants, but maybe waiting until spring is better for plants like chrysanthemums, echinaceas , rudbeckias, salvias, asters, and probably other several others.

(an aster with green growth at its base)

Now why wait to prune? The dead sticks and leaves that hang around protect the base of the plant from direct frost damage. Sure it’s still cold but the branches protect and shield the plant from too much cold. Despite sub-freezing temperatures our plants look ready to sprout new growth at a moments notice. Also by leaving the dead growth and seeds on the plants you provide habitat and food for birds and beneficial insects. It might even be dangerous for the plants to get pruned in the fall since some plants will respond to pruning by growing new growth which would get frost bit by the cold temperatures. In the future all of my perennials might just have wait until spring to get their trim.

6 thoughts on “Perennial Plant Pruning”

  1. I was in the garden just this week while it was cold, trimming some perennials back. Now is probably the time but I don’t trim my mums until about March, when I am sure the worst of the cold has gone by. I have read to wait on them. You are doing a good thing waiting and I agree with you, most people trim due to aesthetics.

  2. It seems to me that waiting until frost danger has past and right before new growth begins would be the best time for most perennials. The dead stems don’t really bother me, since I’m not out as much in the winter.

    What kinds of perennials did you trim?

  3. I trimmed brown eyes, sedum and eupatoriums. I left mums, coneflowers (for the birds), grasses (for interest), and mums. I have not touched the coreopsis or veronica or powis castle. there may be a few more. i will get them once they start looking really ratty or new growth comes. the coreopsis are so small and low that really they don’t need cutting back, just tidiing up in the spring. i like to do a little at a time. i hate to cut ornamental grasses and monkey grass. oh well. such is gardening.

  4. Glad you posted about this topic Dave! I was wondering when the correct time to prune the dead was and now I know… I prefer to leave it as is for the critters to utilize also. I am an animal lover to the core so anything to help my feathered friends is okay by me…

    Should you cut back the dead of a Mexican Heather Bush? Or will it come back from the dead growth which remains above the ground? I cut mine back thinking it died out completely (annual) but left the roots in the ground and darn if the thing did not come back (perennial???) and beautiful this past year!

    This year, I left everything in the garden dead as can be. Hopefully the birds have enjoyed the shelter and seed food…

  5. Skeeter,

    Thanks for dropping by! Mexican Heather is a perennial in its native area (Mexico) or in zones 9-11. I would suspect that in a milder winter it will come back in zones 7-8. I have one that we put in a pot and brought into the garage for the winter. It still has some green on it but it is mostly faded out. I’ll clip the dead stuff back to help it flush out when the weather is warmer. To help cheat the zone a bit you could take a rock or two and put them near the plant. The rocks should warm up in the sun and create a micro climate. What zone are you in?

  6. We seem to be (kind of) in between Zones 7 and 8… We had a mild winter last year so that is probably why the Mexican heather returned so nicely this year. We have had several days below freezing so far this winter so we may loose it this year. Will be interesting to see what happens. Neat idea of the rocks!

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