Newsflash: trees will die if their roots can’t establish

I’ve blogged before about the importance of getting tree roots in contact with the landscape soil during transplanting (you can find those posts here, here, here, here, and here). My advice to bareroot woody species upon installation is often ignored in favor of the quick-n-easy methods so often showcased on HGTV (“A complete landscape makeover in a weekend!”). And of course everything looks great…for a while. Let’s see what happens after a few years.

Below are photos of a pine tree, several of which were installed in 2007 at my children’s school (The Bush School in Seattle):

 

Not only is this pine tree planted too deeply (you can’t see the root flare, so it’s too deep), but the twine and burlap were not removed, leaving the roots encased in clay.  Furthermore, we’re not sure how great a root system this tree has since we can’t see it.  Even more horrific, the orange nylon twine is beginning to girdle the trunk.  What’s been planted is a big ball o’ trouble.

I sent these photos and my concerns to the administration and advised them to have the installers (low bid, of course) redo the planting before the one year warranty expired.  My advice was ignored, and here we are three years later:

This particular tree has declined to the point that the foliage is chlorotic and the uppermost needles are dead.  It’s symptomatic of a root system that has failed to establish, which is what I predicted would happen.  But it’s long past the warranty period, so if this tree is replaced the school will have to pay for it…again.  (Though it’s hard to see in this compressed photo, the pine next to this one also has top dieback, and I’ll continue to follow its decline.)

Many professionals, including some of my fellow GPs, disagree with the bare-root approach.  But based on this evidence, how could one argue that bare-rooting would not have been preferable to decline and death?

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Linda Chalker-Scott

Dr. Linda Chalker-Scott has a Ph.D. in Horticulture from Oregon State University and is an ISA certified arborist and an ASCA consulting arborist. She is WSU’s Extension Urban Horticulturist and an Associate Professor in the Department of Horticulture, and holds two affiliate associate professor positions at University of Washington. She conducts research in applied plant and soil sciences, publishing the results in scientific articles and university Extension fact sheets. Linda also is the award-winning author of five books: the horticultural myth-busting The Informed Gardener (2008) and The Informed Gardener Blooms Again (2010) from the University of Washington Press and Sustainable Landscapes and Gardens: Good Science – Practical Application (2009) from GFG Publishing, Inc., and How Plants Work: The Science Behind the Amazing Things Plants Do from Timber Press (2015). Her latest effort is an update of Art Kruckeberg’s Gardening with Native Plants of the Pacific Northwest from UW Press (2019). In 2018 Linda was featured in a video series – The Science of Gardening – produced by The Great Courses. She also is one of the Garden Professors – a group of academic colleagues who educate and entertain through their blog and Facebook pages. Linda’s contribution to gardeners was recognized in 2017 by the Association for Garden Communicators as the first recipient of their Cynthia Westcott Scientific Writing Award. "The Garden Professors" Facebook page - www.facebook.com/TheGardenProfessors "The Garden Professors" Facebook group - www.facebook.com/groups/GardenProfessors Books: http://www.sustainablelandscapesandgardens.com

16 thoughts on “Newsflash: trees will die if their roots can’t establish”

  1. I qeuss you went over this is an earlier posting that I didn’t see or more likely forgot about.
    By bareroot approach do you mean that all the soil should be removed from the root ball prior to planting?

  2. Linda, this is the second posting in a row from you with a question that surprised me (hopefully by design). Today’s question is almost too loaded for me to take seriously. I don’t think anyone would argue that bare rooting is preferable to the decline and death you illustrated, but I’m not convinced it’s an either/or proposition. Might removing the twine and burlap and planting at the correct depth have also led to success?

  3. @Frosty, I’ll put some links into this that go back to the other posts. Paul, even if you took off the burlap and twine (and many nurseries void your warranty if you do even that), you still have to find the crown to plant it at the correct depth. (In an earlier post, the crown was a full 10″ below the top of the clay ball.) This will involve removing the clay. And yes, I’m arguing that bare rooting is better!

  4. Linda, I agree that you need to find the crown to determine the correct planting depth and I agree that if the crown is buried in the root ball, that you may essentially bare-root the tree to find the crown. However, I still take issue with the initial question. You asked “how could one argue that bare-rooting would not have been preferable to decline and death” (and kind of called out your fellow GPs in the process). I’ve read this blog for a little over a year and come to think of you as a very fair and straight forward person – always science first (and with particularly good taste in fencing). While the post pointed out common planting mistakes, the final question was, I thought, loaded and out of character. You (possibly inadvertently) posed your question so that everyone had to agree – no one prefers death and decline to bare-ro
    19e0
    oting. Could bare-rooting these trees before planting have prevented the noted problems? Arguably, yes. Is bare-rooting the ONLY way to have saved these trees from death and decline, there’s no way to know without a horticultural autopsy. I miss the fair and scientific Linda.

  5. Oh, Paul, that hurts! I agree it’s a loaded question, but the science that’s out there comparing the three production methods – bare-root, containerized and B&B trees – is that bare-root ultimately outperform the other methods once transplanted. It takes them longer to get going (because they have to develop a root system first), but that the root problems inherent in many containerized and B&B trees ultimately stunt their performance. Add to that the differences between native soil and clay/growth media resulting in poor water and gas transfer. We’re stacking the odds against plant survival by creating and then failing to remove barriers to root establishment.
    I’ve done a number of horticultural CSIs over the last 10+ years, and in every single case I’ve seen(of younger trees anyway) it’s been because roots have failed to establish.
    To be “fair and balanced” I will mention that another method of planting – cut and spread – also is successful with containerized plants. But I’ve seen nothing for B&B trees in between planting the intact rootball and removing the soil completely – at least not in the scientific literature.

  6. VG, I’ve only been involved with one magnolia transplant, and I’d advise soaking the rootball as opposed to using a stream of water from a hose. It’s a little less disruptive to the ropy, succulent root system. Even so, broken roots are stimulated to begin regrowth once they’re underground with sufficient moisture. I’d be curious to hear from others who have bare-rooted magnolias from B&B.

  7. If you don’t bare root plants, you don’t know what the growers have been up to. If I’d bare rooted my Arbutus ‘Marina’ before planting, I’d have discovered the solid ball of sawdust in the middle, and I might still have it. I pretty much bare root everything now, including plants that don’t like their roots disturbed. I’ve been lucky with that so far.

  8. Good for you Deirdre, and I’ll second your observation. Bare-rooting may seem extreme, but at least you end up with a root system in direct contact with the native soil, rather than entombed in stuff.

  9. Boyohboyohboy. I’m with Linda and Deirdre here. I can’t think of a tree I’ve gotten to plant in the last several years that didn’t need some kind of root flare excavation something contractors have no interest in doing. Bare-rooting a B&B tree is a scary proposition, but it’s better to be able to see what you’re dealing with and to do what you can to fix it than to remain ignorant and then find out, once that young tree has gone into severe decline and/or died, that the root mass was a mess. When you start to explore a root ball, you might find J-rooting (all the roots growing horizontally to one side beneath the trunk butt), circling and girdling roots, wildly crossing roots, rock-hard clay or pure sand or sawdust, and secondary root systems, which indicate that the tree is struggling to keep growing even with its trunk flare growing. I’m hoping to have a presentation on this issue ready next spring, with the aim of doing something to educate people on what to look for and how to plant the trees coming out of the nurseries these days.

  10. Woops — sorry. I meant to say ‘struggling to keep growing even with its root flare covered up.’ And now I’ll wipe the foam from my mouth.

  11. You know what’s interesting…it seems there is a definite gender bias on this topic. Deb, I’m glad you’re on board with educational efforts. I’ve been doing a talk on root washing for a number of years. Photos of tree post-mortems, plus photos of the process and several years of follow up help convince people that (1) there is a problem, if only locally, and (2) that it’s worth it to address the problem early rather than wait and see.

  12. Linda, it’s also quite effective, if your venue has the space and you build the time into your talk, to bring in an actual B&B tree and to dissect its root ball right there. Nothing like seeing the phenomenon in three dimensions to understand it.

  13. Yup, Deb, I’ve done that too. Every single time there’s been at least one problem. It’s messy so it doesn’t work everywhere, but it is the best way to make the argument.

  14. I was thrilled to have found this discussion. My starting question was whether I could safely bare- root a 15 gallon Arbutus ‘Marina’. After lots of on-line searching I found your discussion.

    After reading your discussion I am willing to take the chance to perform that procedure.

    Perhaps I will tell my clients that if the tree dies I will pay to replace it because I have no experience, specifically, completely, bare-rooting a ‘Marina’.

    Then, my clients who are, perhaps in their 70s – 80s, told me they want me to buy a larger plant. I began thinking about the container root problems you discussed. I think I will just stick to my preference for planting smaller trees and explain to them why that is what I recommend. (I don’t like the fact that this may disappoint them because Arbutus ‘Marina’ is reputed to be a slow grower. )

    Thank you all for your passion for educating about the research and the importance of doing the job correctly.

    I would appreciate getting any feedback you may have for me.
    Beryl

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