The idea of “cleaning up” your perennials in the fall should have died out decades ago. It’s never been necessary and in fact the tradition of cutting perennials to the ground in late autumn is even harmful. You’ll find that perennials grow better if you simply leave them alone in the fall.
Because, on one side, the dead and dying leaves help protect the plant not only from the cold, but especially from freezing and thawing (usually much more deadly than cold itself). Dead leaves are a natural insulator.
But also, remember a detail that can’t be emphasized enough: the best fertilizer for any plant is its own foliage. Its leaves contain exactly the minerals the plant needs to grow and bloom well. So, Mother Nature devised a wonderful system whereby the old leaves die, but decompose on the spot to feed the plant the following year. Millions of years went into developing this self-sustaining system … yet so many gardeners still think they know better than Mother Nature and cut the leaves off.
Cut off the plant’s leaves and you’ll have to replace the minerals lost with expensive fertilizer!
Think of it this way: if you remove the plant’s dying leaves, you’ve made the soil the plant grows in poorer, so you’ll have to replace the missing minerals with fertilizer next spring. So, you just added two useless activities to your list of things to do in the garden (cut off perennial leaves in the fall, apply fertilizer in the spring) and, worse yet, you have to pay for the fertilizer!
No Spring Cleaning Either
Of course, there are gardeners who will say they cut the leaves off in the fall so they won’t have to do so in the spring, insisting that it is more pleasant to pick up relatively dry leaves (in the fall) than leaves soaked by a long winter under the snow (in the spring) … but that’s a sign that they still don’t understand Mother Nature.
The leaves of perennials decompose during the winter. They are not there in spring or, if still present, are in a state of decomposition so advanced that if you let them continue, in most cases, there will literally be nothing left before summer even begins.
All that’s left to “clean up” in the spring (and only on some perennials) are the dead flower stalks. They have, in many cases, been feeding the local bird population over the winter, but that role is over by spring. So, when the snow melts, if these stems are still standing and if they bother you, simply snap them off at the base and place them on the ground at the base of the mother plant. That way they will continue their role of feeding momma and will decompose in their turn over the summer.
Good Bugs Against Bad Bugs
Moreover, often beneficial insects overwinter in and on the dead leaves and hollow stems of your perennials. If you remove them in the fall, it’s like welcoming undesirable insects into your garden. Let the leaves and stems decompose on the spot and the beneficial insects will already present when the bad bugs awaken.
In conclusion, the fall cleanup of perennials is a waste of time and it is even harmful. So why bother? Instead, take a laidback attitude and let Ma Nature do her thing!
Article originally published on October 14, 2015.
Mine too! Thanks!
Great article as usual, Larry. Does this apply to all perennials, including peonies? I was always told to cut back my peonies before the frost.
I never do. My father always did, though.
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Larry, thank you so much for this article. I was taught incorrect gardening techniques and I never even questioned them until I started reading articles like yours. My goal was to create a beautiful large garden that attracted pollinators, butterflies, and birds. I wanted to help the environment BUT actually I wasn’t. As the plants in my garden were about to produce seeds, berries, and shelter in the fall for the creatures I claimed to care about, I whacked all the plants down the ground, thinking fall clean-up was kind of mandatory. Ugh, what was I thinking. It seems so counterproductive to think the garden ends in fall when in reality that’s when many creatures need it most for shelter and food for the upcoming winter.
I contacted my local cooperative extension and they second your suggestion. They told me to leave all plants standing over the winter and to clean up in spring when the temperature is above 50 for a few days in a row. That would give any overwintering pollinators time to wake up.
I’m so glad you are getting your message out to people because in truth many of us are self-taught gardeners who might be following poor practices.
I tend to do it early because we can be out in the garden all through winter, and there is no snow to cover it up. Also, I get the habit from cleaning under roses and fruit trees to inhibit the spread of disease. Of course, that means nothing for the perennials here.
I have been cutting back perennials that have disease and it seems to be keeping the problems in check. The leaf spot on my echinaceas comes much later in the season and there is less of it as well. It has disappeared from one side of the house, where there are fewer plants. I have been thinning out the plants in the fuller pollinator garden. Would a lazy gardener just not worry about it?
Logically, you would cut out diseased leaves… or even more logically, removed diseased plants to replace them by ones that are disease resistant. Selectively thinning plants? If the garden is very dense, that makes sense, but I would tend to let the plants duke it out and leave those that win the battle take over.
I very much enjoy your blog; you are the most practical gardener on the internet! However, your comments about the decomposition of perennial tops and of tree leaves don’t apply everywhere in Canada. Here on the Prairies, the air is so dry that full decomposition takes about two years in a flowerbed. Last year’s perennial tops are straw in the spring, and still quite intact by the following fall. I agree that they should be left standing for the winter, but they interfere with thawing and with garden management if left in place in the spring.
True enough, I’ve always gardened in a humid climate and things rot here amazingly quickly. In your situation, I’d likely view the not-yet-processed leaves as a mulch. And the soil is going to thaw anyway.
Thank you for that comment Roland, I was also wondering this here in Edmonton. Larry, follow-up question: We have a large bed of perennial native wildflowers (first year) that we will be leaving to rot best they can, as the soil in our garden is in the process of rejuvenating after a decade of neglect by previous owners. I have many litres of still-rich soil from container gardening this year, and I was considering dumping this leftover soil over top of the wildflower corpses before the snow. Thoughts? Wait until Spring? Thanks, LOVE your blog!
It would work perfectly and you could do it in the spring or fall.
Great post, thanks for the advice.
Sounds good to me though I will still cut a few back that are very ugly
Not a problem.
This really makes sense. Thank you!