Inspecting nursery plants, part 1

I’m frequently asked to give seminars on selecting healthy plants at the nursery, especially trees and shrubs which can run hundreds of dollars.  (Nobody seems to want a seminar on how to pick out a flat of petunias.)  I routinely visit nurseries with my camera so I can record examples of good and not-so-good choices.  What better forum to share these than on our blog?   I’m also curious whether the problems we see in the Pacific NW are found elsewhere in the country, or in the world for that matter.  So today we’ll hunker down on our hands and knees and inspect root flares.

The root flare (or root crown) is the point where the trunk meets the roots and should be wider than the rest of the trunk.   The photo below shows this clearly:

In balled and burlapped trees and shrubs, you might not be able to find the root flare as soil and/or burlap cover the root flare.  The tree below is burlapped far above its root flare:

Over time, many trees and shrubs buried too deeply will develop trunk rot.  You can inspect for rot by gently peeling back the burlap from the trunk and looking for damage.  Don’t worry, this doesn’t hurt the root ball or the trunk:

The tree in the above example already has some red flags – the presence of weeds on the soil surface suggests that it’s been in this pot for a long time.  (And no, you don’t want to buy this tree.)
The most dramatic example of the problems that can occur is this weeping larch, which has been completely girdled by the rot induced by the burlap and twine around the trunk:

Lesson:  It’s cheaper to wash your now-dirty pants than it is to buy (and eventually replace) a poor quality plant.

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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

13 thoughts on “Inspecting nursery plants, part 1”

  1. So sad! That poor larch…*sniffle*

    For these very reasons, I always suggest taking a pocket knife with you on any plant-shopping expeditions.

  2. A nice complement to the wire cutters that I often carry when looking for neglected staking on street trees. Don't we make a nice pair!

  3. You also correct the street-tree stakes ?!? I've been doing it so long, the kids think we're going for a walk when Mom puts the wire cutters & Felcos in her pockets !

  4. We have similar problems down under. Ours tend to be more root system problems as most landscape trees are container grown, minus the ball and burlap. Please forgive my complete ignorance, but what is advantageous about the b&b method of tree cultivation? Is the method only used for specific taxa? The closest I've come to seeing the problems in the above photos is mulching too close to the tree once it's been planted.

  5. @ Linda,
    In the Domincan Republic I notice the landscaping tool used for everything from pruning, weeding, edging, etc. is a MACHETE. I felt so inadequate packing my dinky felcos…

  6. Jimbo, Putting B&B into containers is something I rarely see here. The times that I've seen it they dump the tree in and fill it the rest of the way with soil/media/compost — sometimes even wood chips — it's a very poor method. Properly harvested B&B stock isn't held in a container. The biggest advantage of B&B harvest is the size of the tree that can be moved — up to and including a 9 inch caliper for many trees. Larger with specialty equipment.

  7. B&B in containers may be a poor method, but that's the way nearly all B&B is sold here. People like the stability of the containers and they don't like the dirty ball shedding all over the back of their nice SUVs. I've been helping with an installation of large conifers and every single one was B&B in a container. All had a mass of fine roots in the container media, which made it a nightmare trying to get the burlap and baskets off.

    Jimbo, people here want instant gratification in their landscape as well as elsewhere, so they insist on large specimens, which are more easily grown B&B than containers. Perhaps you are more patient in Australia!

  8. We don't see many B&Bs in containers here in Massachusetts, though container-grown plants are getting more popular. MIght another advantage of B&B trees, besides the ease of harvest that Linda noted, be that the root balls of trees grown in the ground are protected from freezing temperatures until they're dug? I knew a distributor who specialized in selling Japanese maples, many of which he bought from nurseries in Washington State. They were beautiful, container-grown plants, but he lost a huge quantity of stock during a late freeze, and he had to sell what he was able to salvage at really low prices.
    I'm another guerilla wire-cutter! Nice to know there are a bunch of us!

  9. Thanks for your replies Jeff, Linda and Deb. Most advanced specimens grown here for transplant are grown in large, above ground containers. But like you said, Linda, perhaps we are more patient here in Australia, as the vast majority of trees I've planted in landscapes haven't been terribly advanced specimens. I like to garden in line with the underpinning biology of the trees, and in my experience it's far more preferable for the trees concerned to plant tube stock or 1 or 2 year old saplings. No instant effect, mind you, but I reckon it grows healthier and more successful amenity trees. A lot of Eucalyptus and Corymbia are planted around Melbourne, and once in the ground they grow like the clappers! There are some replacement strategies the Melbourne City Council have put in place for the Ulmus species we have growing along avenues here in Melbourne (perhaps senescing is a better word, quite a number of them are already on their way out). The replacement trees are only about 2 years old, possible 3, and all are container grown. I've seen very few B&B trees around these parts – it's always interesting to others' preferences on the other side of the world.

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