Return to the Maples Forum | Post a Follow-Up

Help with root bound maples

Posted by GreenHavenGarden 6 (My Page) on
Sun, Jul 28, 13 at 13:11

Can someone help me (either with directions or point me to some literature or a good book) with the proper way to bare root and correct root bound trees.

I've bought many maples recently (over 60) and despite shopping at good nurseries, many were root bound. The trees range from 3gallon size up to 20 gallon. Most I'm planting in the ground but some I'm keeping in pots.

I usually remove all the soil with a strong hose spray and try my best to untangle the roots but im not sure how aggressive it's ok to be, should I do it all at once and how much I can cut off without hurting the tree. Occasionally the roots are a big mess that are shaped like the pot.

I know I should be more careful when choosing trees but when you see a variety that you want and don't yet have and there happens to be only one available, it's hard to say no and not purchase it. That's how I ended up with some root bound trees.

Any help would be greatly appreciated.

Follow-Up Postings:

RE: Help with root bound maples

I think your method sounds reasonable. I would wait until fall or early spring so that they have time to heal and grow new fibrous roots, which are more important for the trees than the big, woody roots that are bound to girdle them in pots. I found an extensive post about root pruning from somewhere on here, and I'd suggest also looking at the bonsai forum, as root pruning is standard practice for those folks.

as a backup, you might try air layering a few of your favorites, just in case the root pruning doesn't work out.

Here is a link that might be useful: root pruning maples

RE: Help with root bound maples

Do some online research under the topic "root washing".

Personally, this is something I would be rather hesitant to do with JM's, simply because they have such a sensitive root system. And would highly discourage doing it before the tree was fully dormant as is the preferred time for root pruning as well.

I've been in the nursery industry for years, with JM's kind of a specialty, and while there is ALWAYS the potential for containerized plants to be rootbound, I have found this NOT to be a huge problem here or with the growers we usually purchase from. In many cases, smaller plants offer less of a concern, simply because they haven't been around long enough to develop the problems. Bigger plants, bigger risk.

But even with a number of my own containerized JM's that I haven't up-potted soon enough, I have found that just gently massaging the rootball - not bare rooting/washing it or cutting through any roots - is enough to loosen the feeder roots to encourage their spread.

Girdling is another matter altogether and I might approach that differently :-) But again, I seldom see that with our maples.

RE: Help with root bound maples

  • Posted by botann z8 SEof Seattle (My Page) on
    Thu, Aug 1, 13 at 11:57

I transplant a lot of Japanese Maples from pot to the ground at all times of the year here in the PNW. I never wash the roots clean. Just tease them a bit and plant. I cave the sides of the hole in and level with the topsoil from the hole and water well to establish capillary action so the rootball doesn't prematurely dry out.
Washing the roots clean might present more problems than it solves in my opinion.

RE: Help with root bound maples

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sat, Aug 3, 13 at 2:21

GHG - here is a thread that goes into a fair amount of detail about root pruning and repotting containerized trees. Bare-rooting containerized maples is no problem - they tolerate it extremely well. You should also root prune and correct any potential root issues, like roots that grow back toward the center of the root mass, or grow almost straight up or down. Larger roots that cross, grow back toward the center of the root mass, are potentially girdling or encircling, or are j-hooked should also be corrected asap. Ideally, you want the root mass to consist almost entirely of fine roots, with no or very few roots growing directly under the trunk. They should radiate evenly & horizontally from the same ht on the trunk, and quickly branch into finer roots. This is the top of a trident maple I layered to remove the old (and very ugly) root mass and replace it with a new root system:
 photo repots001.jpg
 photo repots013-1.jpg
You can still see the wire I used to constrict flow in the phloem so photosynthate & auxin would collect in the tissues immediately distal to the wire tourniquet. href="" target="_blank"> photo repots005-1.jpg

Maples respond very well to even severe root pruning if you do your repotting in spring just before onset of bud-swell. It's pretty common for me to remove up to 90% of the roots from trees just exiting the quiescent state that follows dormancy . Root pruning and subsequent repotting is the only thing you can do to eliminate the limitations imposed by having allowed the tree (at any point) to reach a state of root congestion that finds you able to lift the root/soil mass from the pot intact. Once that state of root congestion has been allowed to occur, your plant's potential is permanently limited unless the root issues are corrected by root pruning and planting out out or repotting. Potting up or planting out alone cannot eliminate the limitations. It might allow the plant to grow a little closer to normally, which you might interpret as a 'growth spurt', but in fact what you are seeing is the plant growing in what is only a partial return to what would be normal growth. You might as well call any improved growth after potting up as evidence the tree was indeed growing under the limiting effect of root congestion.

After root pruning a trident that previously resided in a 5 gallon nursery can:
trident roots photo tridentroots_zpsc8bd5944.jpg
It'll be moved to a can about half the size and continue its development until it's ready to be trained to something that deserves a nice pot.


This post was edited by tapla on Mon, Aug 12, 13 at 14:11

RE: Help with root bound maples

Thank you for all the info and links. This was exactly what I was needing. I'm surprised to hear that people don't find many JM's pot grown and root bound. I've found so many and from numerous "good" nurseries. The only source that sends me trees that aren't root bound at all is Diana at Topiary Gardens but those are young trees. Most of my larger trees had some issues with roots. I've got quite a few that still need planting or repotted. I bought Vertree's big book of maples hoping it would help with potting/pruning/planting and although it has beautiful pictures it didnt give me the information I was looking for. I appreciate the advice given, especially Al with those pics. It helps a lot. Thanks again :)

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Maples Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here