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Aug 092012
How Do I Transplant Existing Trees?

Do you have a shrub or tree that is planted in the wrong place in your yard? Does your neighbor have a tree that they will let you have, if you move it yourself? Have you wondered how to move a tree and keep it alive? If a tree or shrub is not too big, you can transplant it yourself and save the cost of having it done professionally. Be prepared for some hard work, and take the time to learn how to do it properly. If you work carefully, you can expect a high probability of success in keeping the tree alive and growing after transplanting is complete. The following information will guide you in the transplanting procedure. Recognize that this process can be used for all woody plants, trees, shrubs, or vines. Due to size, trees are the hardest to move, so they will be used as the example

When Should I Transplant?

Transplant early in the spring, after soil frost is gone but before new growth occurs. Once the buds start to break and grow, transplant survival decreases drastically. Plants dug during, or soon after bud break, are intolerant of transplanting especially evergreen trees, but all trees will do better if moved when they are dormant.

What Basic Transplanting Method Should I Use?

Plan to use a ball-and-burlap method for moving a tree. This technique involves moving a large ball of undisturbed soil along with the roots. Keeping soil around the roots is important for survival of trees that have grown unrestricted or unpruned in a yard or landscape situation. The method for digging a root ball will be described in detail below.

How do I Decide if a Tree is Moveable?

The most important consideration for assessing ability to transplant a tree is size. Small trees survive transplanting better than large trees, so the smaller the better. Also, the bigger the tree, the larger the soil ball that should be maintained around roots. A bigger root ball means more weight that must be moved. You must match necessary weight with personal physical ability and tools available for transplanting.

A 24-inch diameter root ball dug to 16 inches deep will weigh anywhere from 200 to 300 pounds, so tree size quickly restricts what is physically possible.

Due simply to the weight involved, it is probably wise to avoid moving trees whose trunks are larger than 2.5 inches in diameter. Alternately, they should simply be cut down or moved with the help of a professional using a mechanical tree spade.

How do I Determine Proper Root Ball Size?

First, figure out the proper diameter for the root ball. As a general rule, for every ONE inch of trunk diameter (measured at 4 inches above the ground), the soil root ball should be 12 inches in diameter. So, if you have a tree whose trunk is 2 inches in diameter at 4 inches above the ground, the root ball should be dug so that it is 24 inches in diameter (with the trunk in the center). Keep in mind that tree height is NOT a factor here. The root ball diameter should be based on the trunk diameter.

Root ball size 1

Diameter less than 20 in. Depth not less than 75% of diameter or 3/4 of width.

Root ball size 2

Diameter 20 to 30 in. Depth not less than 66-2/3% or 2/3 of width.

Root ball size 3

Diameter 31 to 48 in. Depth not less than 60% or 3/5 of width. Balls with a diameter of 30 in. or more should be drum laced.

Next, you will need to decide how deep to dig the root ball for the trees by using the following information:

  • If the root ball diameter < 20 inches: root ball depth should be 75% of the diameter.
  • If the root ball diameter is > 20 inches but < 30 inches: root ball depth should be 66% of the diameter.
Detailed Instructions for Transplanting a Tree
  1. Digging materialsGather tools to complete the transplanting job. A sharp shovel or spade is required. Burlap is used to hold the soil ball together, and nails can be used to “pin” the burlap in place to hold the material on the root ball. Twine can be used to provide extra support to hold the soil ball together. Hand pruners and a sharp pocket knife can be used to prune or cut branches or roots as needed.
  2. Root ball diameterCheck the trunk diameter 4 inches above the ground. Determine the proper root ball diameter and depth using the rules given above. Once you know the diameter then roughly mark a circle of the proper diameter on the ground around the tree with the trunk in the center.
  3. Dig at least one or two inches further out than the mark for the root ball. Use the BACK of the shovel toward the trunk, and push the shovel straight into the ground. Once the shovel sinks into the soil as far as you can comfortably push it, then lift it STRAIGHT OUT of the ground. DO NOT push on the shovel toward the root ball since you can break up the root ball. The idea is to keep the root ball intact without cracking it.
  4. Once you have dug all the way around the trunk by pushing a SHARP shovel into the soil, then you can use the shovel OUTSIDE of your vertical cuts to remove soil. In this way, you are starting to make a vertical cylinder of soil – the root ball – around the trunk. As you remove the soil, avoid putting pressure on the vertical cylinder of soil (here after called the root ball) so that you avoid cracking it. You want the root ball intact.
  5. After removing the excess soil outside of your cut lines, put the BACK of the shovel against the root ball again and dig deeper this time, digging all the way around the root ball and keeping the shovel straight vertically as you dig. Again, avoid putting pressure on the root ball so that you avoid cracking it. After digging deeper all the way around the root ball, remove the soil outside of your cuts so that you have room to dig deeper again.
  6. To make your digging easier, you should probably clear about 8 inches (or more) of soil away from your vertical cuts so that you have room to dig deeper. The more soil you remove to the outside of your cuts, the easier you can dig down, BUT moving that soil out requires plenty of space and your energy to dig it and move it out.
  7. Root ball depthAs you make vertical cuts for the sides of the root ball and dig deeper, you can begin to taper the root ball, perhaps angling your cuts 1 to 2 inches toward the center of the ball for every 12 inches deep that you dig. In this way, you will have a root ball that is wider at the top and tapered to its base. Since you also should have started the root ball a few inches wider than was necessary, you can make vertical cuts to make your root ball smaller while tapering its shape toward the bottom of the ball. As you make the vertical cuts on the soil cylinder/root ball, you may encounter some very thick roots. If your shovel is sharp enough, it should cut the root(s) with a few good hard strokes or pushes. If the root is either too large or your shovel too dull, AVOID continually hitting or slamming the root with the shovel, since this practice causes excess root damage and will probably help break the root ball. Instead, have a sharp pair of loppers (or other sharp pruning tool) with you to cut the root so that you can continue digging after the root is cut.
  8. Once you dig deep enough, based on the depths provided above, you should start to undercut the root ball. This procedure involves using your shovel to make/cut the bottom of the root ball. You will need to cut under the cylinder of soil from the outside, so this procedure is more readily accomplished (but not necessarily easily accomplished) if you removed the soil from a large area outside of the root ball. Undercutting the root ball must be done carefully since you can easily crack the root ball and ruin all your efforts to this point. The goal of undercutting is to cut roots that may be growing vertically (such as the taproot) or close to vertical. To undercut, use the shovel in the regular way (shovel face now toward the tree) and push the blade toward the center of the root ball going around the ball several times. Digging the root ball (soil cylinder) a little deeper than needed (according to the nursery stock standards) will enable you to remove soil – after making some horizontal cuts – at the bottom and ensure that vertical roots are cut. Trying to move the soil ball with a few roots intact under the root ball (particularly the taproot) will nearly always break open the ball.
  9. Once you have dug under the root ball and cut all the roots, you will need to protect the root system so that the soil holds together and the ball does not crack when trying to move the soil. Typically, burlap is used for holding the root ball together, but other types of material can be used as long as the material is strong enough not stretch and break when trying to tie it around the soil ball. You will need different sized squares of material to hold the soil together depending on the ball size. For example, a 24-inch diameter root ball may require a 36-inch by 36-inch square piece of burlap.
  10. Once the root ball is cut free in the bottom of the hole, take the burlap square and fold a corner of it down so that it goes to the bottom of the hole. Fold about one-quarter to one third of the burlap down. Next, the long diagonal (from corner to corner) of the burlap is tied around the root ball, using the burlap as a band to hold the soil in place. If you are unable to tie the material around the root ball, use a larger piece of material. After tying the burlap tightly around the root ball, shift the root ball (carefully) so that you can grab the folded down corner of material and pull it under the root ball. In this way, you will have the material under the root ball and can cover the bottom and sides of the ball. Once you grab the corner of the material and cover the bottom of the ball, you may need to re-tie the material around the root ball. As you complete these procedures, be careful to avoid breaking the root ball.
  11. Once the burlap or supporting material is all around the root ball, you can pull the root ball out of the hole by lifting on the soil root ball NOT the tree trunk. Once the root ball is out of the hole you can shift or re-tie the burlap or supporting material as needed. Usually nursery professionals use pinning nails to make the burlap tight on the ball. Also, for root balls larger than 30 inches in diameter, supporting material, such as twine, wire baskets, or even chicken fencing are recommend for supporting the soil ball since it can break easily.
What do I do next?
  1. The shrub or tree should be replanted to its new location as soon as possible, hopefully within one week. In the mean time, prevent the root ball from drying out and try to keep the roots cool. If the root ball must remain out of the soil for more than a week, consider burying the ball in an organic mulch to retain moisture and reduce the soil temperature.
  2. Finally, plant the tree in its new location. Dig the new planting hole for your tree or shrub to the same depth as the root ball. Do not bury it too deep. See the planting instructions under the Trees, Shrubs, and Vines section of this web site for more details.
 August 9, 2012