The Do’s and Don’ts of Tree Pollarding

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Pollarded tree with obvious knobs

Pollarding is a tree pruning technique that develops a framework of bare scaffold branches with a gnarly knob at the end of each branch.  Every spring numerous straight long and leafy sprouts emerge from these knobs to produce a dense, shady canopy. 

 As far as we know pollarding started in the Middle Ages in Europe in order to produce kindling for fire places and fodder for livestock.  Nowadays we pollard to manage the size of a tree that is too large for its space and/or to create a formal look in the landscape.

A good example of pollarding is the band shell area in San Francisco’s Golden Gate Park. It hosts dozens of pollarded sycamores or plane trees (Platanus x acerifolia). 

Pollard Sprouts Photo by Natubes-WikiMedia

Pollard Sprouts Photo by Natubes-WikiMedia

To be perfectly honest I’m not a fan of pollarding.  I do respect  the impact that a grove of pollarded trees has on a formal landscape. But it also pains me to see stunted versions of what could be beautiful, towering majestic trees. I’d prefer to see smaller trees chosen for smaller spaces.  And a formal garden can be created in so many other ways.

The biggest problem I have with pollarding is that it is so often done wrong. A properly pollarded tree can live a long and healthy life.  But it needs regular and appropriate maintenance.  

  1. The sprouts should be removed every one to two years. Pollard sprouts are weakly attached to the knob. If they are left on the tree for years and years the sprouts become thick and heavy. They become a potential hazard.
  2. The sprouts should be removed all the way back to the knob
    These sprouts have been left on the knob too many years and they haven't been pruned back to the original knob consistently

    These sprouts have been left on the knob too many years and they haven’t been pruned back to the original knob consistently

    In other words don’t leave little stubby branches on the knob. Cutting all the way back to the knob makes it easier for the tree to seal off the pruning wound and assists the tree in preserving important energy resources (carbohydrates) in the knob. This is because pollard knobs compartmentalize readily.
     
  3. Start the pollarding process when the tree is young – two or three years old.  Ideally you will never need to cut a limb or sprout that is more than 1” in diameter.  Over a few years a small knob will develop and expand. Each year the knob will grow larger and will harbor dormant buds, carbohydrates and wound calluses.
  4. Do not attempt to start the pollarding process on a mature tree that has not been pollarded before.  This is REALLY hard on a tree. Sprouts will emerge from below the cuts and it will look sort of like pollarding. But bluntly cutting mid-node through

    This tree has been topped. This is not pollarding

    Don’t do this. This tree has been topped. This is not pollarding

    thick and/or mature branches is called topping. Trees heal poorly from topping cuts. Topping cuts instigate branch decay due to the slow healing process and exposure to pathogens.  Topping cuts weaken the tree’s structure and can shorten the life of the tree.  How do you know if the tree has been pollarded before?  It has a knob.

  5. Choose trees that take well to pollarding. Sycamores, mulberries and horse chestnuts respond well.  You can find other species online by searching for “trees for pollarding”.
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21 Responses to The Do’s and Don’ts of Tree Pollarding

  1. Pingback: Weeping Willow Tree

  2. Eli says:

    Hello, I found your article on pollarding very interesting. I especially noticed the part about not doing it to older trees, which brings me to my follow-up question. I have got a mature flowering plum tree (20-25′ tall, 1′ diameter) that is being hollowed out by a shelf fungus ( major wind throw hazard). I was wondering if it could be pollarded down to a safe height. I figure the the main reason not to do this (preventing infection) is moot, but I would appreciate a second opinion.

    Thank you , Eli

    • Karen says:

      Hello Eli, It’s too late to develop proper pollarding in a mature tree. Pollarding should be developed when the tree is young. At this point pollarding would just weaken the tree further.

      • Dave says:

        This seems like very definitive advice. If as a last resort because the tree is dying, why not attempt a pollard. Plums, being a fruit tree, should produce lots of stress growth, making pollarding possible. It is my understanding that this practice is commonly used on mature trees which are failing.
        All comments welcome

        • Karen says:

          I don’t recommend starting to pollard a mature tree. The wounds are too large and at awkward positions for effective healing. Yes, you can pollard plums but I would start them young.

  3. Christina Metcalfe says:

    regarding pollarding. How often should it be done; we do it every 7 years, and it seems we have to remove so much of the tree that it resprouts at its base.

    Also, does drought affect the schedule?

    Thanks.

  4. Christina Metcalfe says:

    regarding pollarding. How often should it be done; we do it every 7 years, and it seems we have to remove so much of the tree that it resprouts at its base.

    Also, does drought affect the schedule?

    Thanks.

    • Karen says:

      Christina, Trees should be pollarded every year in the winter when they are dormant. The drought does not impact that schedule.

  5. Maria Hennessy says:

    i have a very large white mulberry that was pollarded long before I bought this house. i cut the whips back every year, but the knobs have become so large that i feared for an accident. I told my partner that we should use a chain saw to remove half of each knob. I have seen this done at the school where I teach. i went away for a week and my partner and his son cut the knobs off entirely. They said that it was too difficult to remove half of each knob. Aside from painting the wounds, what can I do to make sure that they haven’t destroyed the tree?

    • Karen says:

      Maria, Painting won’t save the tree. The tree will have to heal itself. Cutting off the knobs in any ways if very hard on the tree. The best you can do is nurture the tree by giving it adequate irrigation and nutrition. Karen

  6. Barbara says:

    What time of year is it appropriate to remove the sprouts? The Acer griseum that I have been pollarding sends out sprouts over the fall/winter. I am reluctant to remove them in the late winter/early spring because this is when the sap is flowing. I do not want to make the tree expel fluid from those cuts.

    • Karen says:

      Hi Barbara, I’m very sorry for the late reply. I didn’t see your message before. Remove the sprouts in mid-winter when the tree is dormant. If the sap is running it is a bit late in the season. Consider late December or January. Karen

  7. Bruce Murray says:

    Hi Karen,

    I have a three year old Plane tree that I would like to begin to pollard. I have not been able to find a source that illustrates how to start the pollarding process on a tree that has never been pollarded. Can you advise me? Or point me to a source?

    • Karen says:

      Hello Bruce, I found a short article online that I think will get you started. http://www.gardengatemagazine.com/63pollarding/. About half way down this article there is Step 1 which they recommend you do the first year. You are 2 years behind but I think it won’t matter as the tree is still young. The illustration should help you figure out where to make your first cuts. Do this next winter when your plane tree is dormant.

      • Bruce Murray says:

        Thank you, Karen. One simple question. When the article says you should begin in the “first year,” what is the assumption about how large this tree is in its “first year?”

        If, for instance, I would like a grove of plane trees to provide a canopy at about 12 feet, do I wait until the point at which I first top the tree is 12 feet above the ground?

        Will the height of the tree continue to increase after topping it, or does the topping stop all vertical growth?

  8. Mike Murphy says:

    where can I purchase pollarded sycamore / London plane tree ? Lower Connecticut

    • Karen says:

      HI Mike, Sorry for the very tardy reply. For a long phase I wasn’t getting notice when people posted comments and questions. Perhaps you have already found your sycamore. I have never purchased a fully pollarded tree before. Usually the pollarding is developed over the years. You can contact your local nursery and see if they can order anything like that for you. Karen

  9. Violet martinez says:

    Hello Karen, looking for some expert advise. Can you tell us how do I get a mulberry tree to have a full canopy again. The mulberry is roughly about 40 years old. We love it! We cut back long branches throughout the year, but it’s losing it fullness. We also have a new one that is about 5 yrs old and would like to train it to have a full canopy too.

    Please advise,
    Violet

    • Karen says:

      Hello Violet, Let the branches on the 5 year old tree keep growning into their fullness. Do not cut them back. If there are branches growing in wacky directions remove those branches only and keep the ones that are growing outward. Karen

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