How to Transplant Holly Bushes
Holly is a welcome green spot in the garden in winter, especially with its festive berries. If you decide you need to move it elsewhere, however, you'll be facing a big job—not to mention a hazardous one, because those spiked leaves pack a pokey punch.
The larger your tree is, the tougher the holly (Ilex, USDA plant hardiness zones 5 to 9) will be to transplant and the longer its road to recovery. Timing is important too; to limit transplant shock, transplant only in spring or early fall.
Tips for Transplanting Established Holly Trees
Here are some helpful tips for transplanting an already established holly tree.
Don't Transplant a Holly Tree in Summer or Winter
First off, avoid transplanting any plant, shrub or tree in summer. The heat will create an unnecessarily difficult environment to sustain new root formation, so just don't do it.
And for evergreens, such as holly, don't transplant them in the winter either. Evergreen trees continue to lose moisture over winter, and the soil may not be conducive to new root growth due to compaction or freezing temperatures.
For evergreens, such as holly, don't transplant in either winter or summer.
Protect the Root Ball
The amount of roots you can bring with your tree will greatly impact its ability to pull out of transplant shock and reestablish itself in a new location.
Try to plan ahead because large trees can also greatly benefit from root pruning several months in advance of transplant. Root pruning entails digging a trench around the tree the size of the root ball you wish to retain. This severs many of the roots, which then encourages the development of smaller roots within a confined area before transplanting.
For a fall transplanting, root prune in March or early spring for your location; for a spring transplanting, root prune in October or mid-fall in your location.
Clemson Cooperative Extension maintains a table that helps growers identify the size of root ball required for transplanting different sizes of trees. For example, if your tree has a 6-foot branch spread, shoot for a 24-inch root ball, digging the trench 16 inches deep and 12 inches away from the trunk all around.
Maintain a Good Moisture Balance
One of the most common reasons transplanted trees don't survive is improper irrigation—either not enough or too much water. If your soil is very well-draining or somewhat sandy, your tree will need more water, while more clayish soils will create a wetter environment, so your tree will need less water.
Digging Up a Holly Tree
Transplant day! Get everything ready and then get to work. Here are the basics:
Dig the new hole. Dig a hole that's 50 percent wider than the expected root ball at a depth to ensure that the tree will sit at the same level as it does in its existing location. Don't add any supplementary fertilizer or compost to ensure that the tree acclimates to the native soil's environment.
Tie up the branches. Carefully wrap or tie up the branches so they are closer to the tree, not only to protect yourself but to gain better access to dig out the tree.
Dig a trench around the tree. Begin extraction by digging a trench around the tree about 12 inches from the trunk and as deep as possible to prepare to lift as much of the root ball as you can. Use a sharp spade or shovel to make clean cuts into the roots, which helps ensure healing.
Extract the root ball. This sounds easier than it is! This will likely entail digging out soil on one side, rocking the tree back and forth several times to identify still-connected roots, digging out soil on the other side and then repeating.
Root balls can be heavy. For instance, a 15-inch diameter root ball can weigh 200 pounds. Use a tarp or piece of burlap laid on the ground and drag the root ball onto it. You can then drag it to its new location without having to fully lift it. For very large bushes or trees, enlist the help of professionals.
Transplanting a Holly Tree
Transplant the same day you have dug out the tree to avoid having the roots dry out. Set the plant in the center of the hole and then add back soil around the root ball and firm it with your hands.
Water immediately, which will settle the soil more. Continue to add back soil to the hole and tamp the whole thing down with your foot, ensuring that the tree is firmly in its new location.
Water again immediately. Then, monitor the tree's moisture carefully over the next few months, trying to maintain even moisture.
I garden in the Pacific North west, previously Hawaii where I had an avocado orchard. I have a Master Gardeners certificate here in Eugene, Oregon.