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root pruning an acer palmatum dissectum?

Posted by bobb_grow 8a SW BC (My Page) on
Sun, Oct 10, 10 at 22:36

Our neighbour wants give her front yard a total makeover next March or April. She is giving us a beautiful 40 year old red acer palmatum dissectum that is in the way of her new plans. I protested when she told me she was getting rid of it so now she said that she would like us to to take it next spring. It is about 6 feet tall and the trunk is just over 6 inches in diamter.

My question is whether it would be helpful if I gave it a good root pruning in the next few days. My understanding is that in the mild west coast climate of the Fraser Valley, quite a number of new roots would form over the next 6 months. In fact, we have had quite a bit of warm (thought wet) weather this Fall and the soil is still quite warm. I thought that by removing soil from around a planned large root ball, I could prune the roots at least 2 feet down. I then would back fill with composted bark mulch and hope that new feeder roots would have developed by March or April and thus, help the tree get a good start in our front yard. I would plan to gather a group of friends to help me move it across the street.

Does this seem a wise course of action? Or, does anyone have any advice for me about how best to move this beautiful specimen?

Thankyou!

Bob


Follow-Up Postings:

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RE: root pruning an acer palmatum dissectum?

  • Posted by tapla z5b-6a MI (My Page) on
    Tue, Oct 12, 10 at 21:57

Imagine looking down at the tree from directly above it, then imagine an octagon shaped root ball as large as you're comfortable handling. With a sharp spade, dig as deep as you can at the outer limits of your imaginary octagonal root ball, severing the roots on 4 sides of the octagon - call them the N,S,E,W sides. Use loppers if req'd. Next spring, about 6 weeks before you expect bud break, prune the NE, NW, SE, SW sides. This will chase fine feeder roots back closer to the trunk and better prepare the tree for the trauma of lifting. Again, in the spring and just as buds are moving, lift the tree and transplant at the same depth the tree was situated, or a little higher to allow for some settling.

What about hiring a tree spade to do the grunt work?

Al


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RE: root pruning an acer palmatum dissectum?

Thankyou, Tapla.

Interestingly, I received two responses to the same post on the Northwest Garden forum which quite clearly argued against root pruning! Their argument was that root pruning stresses the tree twice, rather than just once, when moving it in the spring. That surprised me b/c I have always heard that root pruning helps prepare the rootball but I it also seems to make some sense.

Do you, or anyone else, have any thoughts about that advice?

Thanks

Bob


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RE: root pruning an acer palmatum dissectum?

  • Posted by bboy USDA 8 Sunset 5 WA (My Page) on
    Sun, Oct 17, 10 at 10:03

...if the proper time is allowed between root pruning and digging, some benefits may occur. However, with the multitude of factors involved, both internally in the plant and environmentally, the likelihood of striking the right combination is challenging. At this point root pruning may be one of those techniques that is best to talk about rather than practice

--Carl E. Whitcomb, Establishment and Maintenance of Landscape Plants (1987 (1991), Lacebark Inc., Stillwater)

Here is a link that might be useful: Establishment and Maintenance of Landscape Plants II


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RE: root pruning an acer palmatum dissectum?

That's for plants that are staying in ground, yes?

I think we're talking about a one-time jobber here, a transplanting.

I'm glad you're reading Whitcomb, though.

Josh


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RE: root pruning an acer palmatum dissectum?

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Oct 20, 10 at 21:16

I'm not being indignant when I say that I've spent hundreds of hours in workshops and lectures listening to bonsai masters and in some cases tree professionals discuss how best to lift established trees. I can say that the general consensus is to root prune, in order to chase the roots back closer to the trunk so you are harvesting a larger fraction of feeder roots instead of only the conductive roots found near the bole.

I'm a huge fan of Dr Whitcomb and quote his works very often, particularly the work 'Plant Production in Containers II'and I agree that root pruning as a tool is best left to those with some experience in that area. I have used it, though less than regularly, as a tool on my trees as well as the trees of others, to help short circuit the affect of a radical top reduction, that affect being a prolific flush of basal shoots and water sprouts. I have also used it extensively as a way to prepare wild trees/shrubs and trees planted and established in the landscape for lifting, prior to being indentured as future bonsai specimens.

My experience is that not only is root pruning to chase roots back to the trunk logical, but it also works quite well in practical application. Keep in mind too, that MANY of the practices that were taken as ironclad in 1987, have long been abandoned. I had dinner with the past president of the Michigan Nurseryman's Assn. not long ago, and for a good part of the evening we discussed 'the way we were'. What I remember very clearly, was him saying, "Al, we don't do ANYTHING the way we did 30 years ago". I even wrote a little piece on that comment that can be found on GW pages somewhere. Of course, I didn't take the 'anything' at face value, but the gist of the conversation was what I alluded to when I talked about 'what used to be iron clad'. Things change.

Just something to think about. If you DO decide to root prune, please know it will be up to you to prevent the ground from becoming too dry, though with the 2-stage process, it should be less an issue than if you pruned 360*.

Whatever you decide - best luck - good growing.

Al


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a clarification

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Oct 21, 10 at 7:41

Pardon me, in the above, I should have been more clear when I said ".... I agree that root pruning as a tool is best left to those with some experience in that area." I offered this as it applies to trees in the landscape. For all trees in containers, root pruning should be considered an essential tool for maintaining trees in peak vitality. According to Dr Whitcomb and most other nurserymen, growth and vitality begin to be permanently affected at about the point where the root/soil mass can be lifted from the container intact. After the plant has reached that point, the deed is done, and even trees planted out will suffer unless the roots are corrected before planting. In order to avoid this issue, potting up BEFORE the planting reaches the point where the root/soil mass can be lifted from the pot intact is required on a continuing basis. Since this is almost impractical for trees we intend to keep for the long term, root pruning starts looking rather attractive.

I didn't say that to bolster my previous comments, as they are pretty much unrelated, but I didn't want anyone growing in containers to think root pruning was taboo. On the contrary, regular root pruning and full repots (changing soil) are your friend and offer the best opportunity for your potted trees to grow at as close to their genetic potential as possible, within the limits of other cultural factors.

Said simply: repotting ensures the possibility trees can grow to their genetic potential within other cultural limiting factors, while potting up ensures they cannot, unless, the potting up process is undertaken, each time, before the critical point where roots and soil can be lifted from the container intact.

I beg a pardon for having drifted a little OT, Bob. Please?

Al


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RE: root pruning an acer palmatum dissectum?

  • Posted by bboy USDA 8 Sunset 5 WA (My Page) on
    Sat, Oct 23, 10 at 11:35

So you're cutting roots off to prevent roots from being lost at transplanting. The logic?


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RE: root pruning an acer palmatum dissectum?

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Oct 23, 10 at 17:13

No - truncating long roots months prior to lifting next spring, to force fine roots close to the bole, thus greatly reducing the trauma @ lifting. Illustrative rhetorical question - would you rather lift a root ball full of only conducting roots, or a rootball that has a good measure of fine rootage as well?

Al


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RE: root pruning an acer palmatum dissectum?

  • Posted by bboy USDA 8 Sunset 5 WA (My Page) on
    Sat, Oct 23, 10 at 21:34

I just transplanted a magnolia today, that had circling roots that were cut back on a prior occasion. As usual, resulting new root growth was concentrated out at the ends, from right behind the cuts. If I had been cutting around the edge of the ball, instead of popping the whole thing out, with a fork, I could have been cutting most of the new roots off. Unless I was very sure to cut well outside of the previous cut.

Better to remove most of the soil, in order to get more roots anyway - instead of subjecting the specimen to advance root pruning etc. in order to get a manageable soil ball. Except with those species that are very sensitive to drying of the roots, with stock that is going to be out of the ground for some time. The time interval different kinds of trees tolerate varies widely, some kinds can sit out of the ground for months and then grow away when re-planted, as though not affected at all. The other extreme is very little apparent tolerance to having their roots out in the air.

What the plant wants is to be left in place, to constantly extend its roots out into fresh soil, over as large an area as possible. Annual pruning of roots of bonsai assists in maintenance of these specimens because cutting of roots is disruptive and results in dwarfing of the top.


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RE: root pruning an acer palmatum dissectum?

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Oct 24, 10 at 13:20

Tone is conversational - not snippy:
Please don't lose sight of something I had already mentioned: I'm not suggesting the use of root pruning as a growth regulatory measure, though it CAN be used in that way if you know what you're doing; and I'm not talking about trees in containers. I'm saying that systematic root pruning months before an anticipated lifting/transplanting, is a very effective tool. It 'chases' fine roots back close to the trunk and can greatly reduce the trauma associated with lifting/transplanting.

Roots 'back-bud' in the same manner as branches. Truncate a branch, and buds activate proximal to the cut; truncate a root, root generation occurs proximal to the truncation. You're going to leave the roots outside of the rootball behind anyway; why not truncate them now and enjoy the benefits of the subsequent regeneration of fine roots that would have been absent in the root ball at the time of lifting for transplant?

I think we need, too, to look at the practicality of bare-rooting or nearly bare-rooting a tree with a 6" trunk in order to collect more roots. If you think this is something that could be practically applied, I'd have to say we're in disagreement. I just think it's a better plan to lift the tree with as much of the intact root/soil mass as is manageable. A plan executed in advance to ensure there are as many fine roots in the root mass just seems like a prudent goal to me.

I'm content to let it go to the jury. ;o)

Al


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RE: root pruning an acer palmatum dissectum?

Thankyou both for a very enlightening conversation; it is the kind of discussion that makes forums like these so helpful to me. And no worries, Al, about 'drifting OT.' We have several bonsai plus some larger plants in pots so I consider the digression a bonus.

Now, to decide what to do with that maple.......

Bob


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RE: root pruning an acer palmatum dissectum?

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Oct 28, 10 at 17:40

.... and thank YOU for going out of your way to offer the kind words, Bob. If there is anything you think I might be able to help you with re your containerized trees .... I'll do my best by you.

Best luck with the landscape tree.

Al


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