“This one secret hack will save you time and money!”

I’m resorting to clickbait tactics to get your attention. Here’s another – “Warning! Graphic photos follow!”

Uncorrected roots in containers or landscapes will create chronic water stress problems for trees.

If you have failing trees on your own property or on property you manage, you need to do one simple thing before you assume that pests or disease are responsible: you need to determine whether the root system is healthy and functional.

Now, I know you can’t see underground, but you can draw some informed conclusions based on whether you can see the root flare. To find the root flare, pull away any mulch or groundcover that’s obstructing your view. Once you can see soil, you should be able to see the root flare. If your tree looks like a utility pole (meaning you can’t see the flare), then it’s been planted incorrectly. This single mistake will have myriad consequences:

No flare = no chance

  1. It’s buried too deeply – the flare needs to be at the surface.
  2. If it’s buried too deeply, it’s likely the tree was planted without removing the materials surrounding the roots. Bare–rooting woody plants before planting is crucial to their survival.
  3. Roots that are buried too deeply will not have sufficient oxygen to establish a fine root system for water and nutrient uptake, much less develop any structural roots.
  4. Moreover, without removing the materials around the root, the roots are less likely to establish into the surrounding native soil. Neither are you able to remove poor structural roots. Check out this post for more information.
  5. A structurally flawed root system, stressed for oxygen and encased in layers of clay (or potting media) and various combinations of burlap, twine, and wire baskets, is not going to establish quickly or well. Increasingly, it’s not able to supply sufficient water to the growing crown.
  6. Oxygen-stressed roots will die, compounding the reduced water uptake problem.
  7. As the crown experiences chronic water stress, it will experience dieback while opportunistic pests and disease take advantage of a tree unable to chemically defend itself.
  8. Opportunistic pests and diseases are not the cause of tree failure – they are simply indicators of an environmental problem. Proper diagnosis is discussed here and here.

Bare-rooting plants allows you to correct defective structural roots before planting.

You should be able to confirm lack of root establishment by performing the wiggle test (that’s the secret hack). This will allow you to see whether the soil around the roots moves. If it does, that means the roots are not established. If the tree has been in the ground for more than 6 months, it’s probably not going to establish. The sooner you can dig up and correctly replant a relatively newly planted tree the better your chances that will recover and establish.

The wiggle test!

Published by

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 a 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

12 thoughts on ““This one secret hack will save you time and money!””

  1. Dr Chalker-Scott, I love reading your posts (and hearing you on podcasts) and greatly appreciate this particular topic … but, how can I (both a professional landscaper and homeowner) convince a contractor to remove the burlap and cage from a 15′ evergreen? They absolutely wouldn’t do it. The only concession they made was to cut their usual planting depth by about 6″ so at least I could scrap away the layers of soil tossed on top post dig, and attempt to get the root flair at soil level or slightly above. It’s terrible for me knowing what I know about this when 4 expensive new trees were installed. Unless I am installing something much smaller, from a container, removing b&b material never happens. Not sure what I am to do with this knowledge. Large landscape contractors have zero interest in changing their time honored practices, no matter how wrong and outdated they are. So I do nothing but fret about these trees. I top dress with organic compost and do my best to keep them hydrated going into the winter. There isn’t one contractor I’ve come across that would ever do this :(((

    1. Rosie, I suggest you find an installer who will respect their client’s wishes. There are increasingly more companies who are willing to follow current science in installing and maintaining trees. You might find them more expensive, but on the other hand they usually have a much longer warranty for their plants.

      Good luck!

      1. The Z 60 nursery and landscape standards are free for the download. There is language in there that describes having the root collar at the grade. Sometimes landscapers will respond to the suggestion that they are open to an ethical complaint to the organizations that they belong to that they are doing substandard practices.

  2. This past spring I purchased a very young container grown Parrotia persica. I knew that I would have to do a root washing in order to unwrap and straighten out the roots and also eliminate the soil-less soil to reduce the interface problems. What I was not prepared for was the fact that ALL the primary structural roots had wound themselves so tightly around each other that you could not unwind them. This required careful and selective root pruning which, as a Certified Arborist, I am capable of doing but always do with the greatest of reticence. Clearly, this tree is now a work in progress, taking care that it is not subjected to water stress. It performed beautifully over the growing season but as those of us who work with trees know, I will have to wait 5 + years to really see if the pre-planting efforts were enough to support healthy long term growth.

    Before buying any containerized material, always take the plant out of the pot to see just how impacted the root system is and of course, ensure that the tree is always planted slightly above grade so that the trunk flare is completely visible.

  3. Thank you. I sometimes deal with trees in the course of my employment for a very small fine gardening business. We are often asked questions about the trees on the properties and we do help plant trees occasionally . I can’t tell you how many incorrectly planted trees I’ve seen because it is pretty much all of them! I appreciate the information you are exposing.

  4. Crucial information. It is essential to follow the first link, to understand that “root flare“ refers to the root collar, where the roots originate at the trunk.

    Too many specifications only refer to “the trunk flare” or “the root flare” or “the flare“ which is a large area that starts where the trunk gets broader at the base, and ends at the root collar.

    When the root management standard was being written, we tried to clarify this essential difference. Right now I am working on a job where 750 trees in a public park were planted too deep. Some of them way too deep.

    In one place, the specifications make clear that the root collar should be at grade. But elsewhere in the specifications, they say flare to grade. So the contractor is trying to avoid the need to replant the trees and remove the soil and roots that are growing above the root collar. which is hard work!

    There is a good chance that they will avoid this work because of the poorly written specifications. As a result, most of the 750 trees will develop serious problems. Words matter! It would be nice to have one dictionary for this industry that everybody agrees to use.

    1. in my own experience with authoring detailed specifications, words must be clarified with extremely detailed plan drawings so there is no mistaking what actions the words translate into. Specifications, consisting of general, detailed and detailed plan drawings, are normally appended to the contract so when the Contractor is a contract signer, they are also a signer to the appended specifications as well as detailed plan drawings.

      There are many existing open access drawings that establish exactly how a tree should be planted in relation to the surrounding grade which can assist with the process

  5. Please address how to deal with fruit trees that have been in pots so long the roots have escaped through the bottom of the pots into the surrounding soil. At what point is the situation hopeless? How much of the roots to cut back before replanting if that is even feasible?

    1. Cut off all roots outside the pot so you can extract the root mass easily. Wash the root mass thoroughly and see if you can rescue the woody root structure; as long as you can do this there is hope. Don’t worry about the fine or fibrous roots. I’ve removed as much as 75% of the woody root mass and had the tree establish roots successfully in 3 months.

  6. I agree with having drawings or pictures being so important. There’s very good reason for the old saying “a picture is worth a thousand words”.

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