The best time to transplant an oak tree is between mid-December and late March when the tree is dormant, but it is no easy task. Transplants are most successful with trees that are only two or three years old and ideally under three feet in height. The pin oak and the red oak are the easiest types of oaks to transplant, but regardless of type, following the steps below will make the process as painless as possible.
Step 1 – Pick a Tree
Make sure the tree you choose is healthy and shows no signs of damage.
Step 2 – Prepare the Transplant Site
Time is of the essence when it comes to transplanting an oak tree. As soon as you remove your tree from the ground, it needs to be transplanted, so have the transplant site ready to go before you start digging. Choose a spot that will accommodate the size of a full-grown oak. This size depends on the type of oak, so do your homework regarding your specific type.
Planting an oak near a street, sidewalk, or a foundation is a bad idea. This can be damaging to the roots and even to the sidewalk or foundation. Oak trees have large root systems that extend even beyond their width. When you are ready to dig, make sure your hole is a few inches larger than the tree's root ball.
Step 3 – Work the Soil
Break up the soil from the hole, and add compost and garden sand to improve its quality and drainage. Keep an eye out for fungus or pests in the soil that could harm your tree's newly transplanted roots.
Step 4 – Dig up the Tree
Dig a trench around the tree about two feet deep. Slowly extend the trench towards the tree until you see evidence of roots. If the tree is very young, the roots may not have traveled very far. You should be able to estimate the depth of the tap root (the main root at the center of the root ball) based on the tree's height. Tap roots are almost as long as the tree is high. Be careful; it is important not to break the tap root while digging out the tree. If the tap root is damaged, your oak tree may not survive. Take the trench to the necessary depth and then start digging towards the tree.
Tip: Avoid digging into the root ball. Continue to dig until you notice the tree start to lean. Then, gently wiggle the tree in its hole to determine if it can be easily removed. Do not pull or jerk. If the tree does not seem loose enough to remove, continue digging carefully. If you can maneuver a shovel under the tree, it is ready to be removed.
Step 5 – Wrap and Move the Tree
Lift the tree out of the trench a few inches. Try to capture as much of the root ball as possible and wrap it in light hessian sacking. Tie the sacking around the trunk of the tree and remove the tree from its hole completely. Transport the tree to its new position as soon as possible.
Tip: If you do not have any hessian sacking, you can use tarp or plastic to wrap the tree roots. However, you must be sure to remove this material before planting!
Step 6 – Plant the Tree
Place the tree into the hole you have prepared. Make sure that the root ball is slightly below soil level and the soil line is at the same point on the trunk that it was in the original spot. Remember that some soil settling will occur in the next few weeks so you may even want to plant your tree lower than seems necessary. Build a platform of soil under the tree, and fill in the rest of the hole with the soil that you have worked. Tamp it down firmly yet carefully around the root ball. You can actually leave the hessian on the root ball. The hessian will encourage root growth by keeping the root ball moist and then slowly decay naturally.
Step 7 – Water and Fertilize the Tree
Directly after planting, drench the soil. Over the next few months, water the tree carefully once or twice a week. A deep soak is much more beneficial than watering with a sprinkler. Remove all attachments from the end of your hose, turn it on to a slow trickle, and leave the open end on your tree for 20 minutes or so.
Spread a layer of organic compost over the newly disturbed soil and work it into the first few inches using a trowel or garden claw. Make sure not to dig deep enough to disturb the roots.
Step 8 – Prop the Tree
There will be no growth in the tree or the root system until the spring, so the tree will have to be supported in case of high winds. Place two strong bamboo stakes on either side of the trunk, with the bottom six inches firmly extending into the ground. Use gardening tape to fasten the tree to the stakes. If you use twine or rope instead of tape, the tree can't move at all and is much more prone to develop a shallow root system. Gardening tape is flexible and allows the tree to move a healthy amount.
Step 9 – Prune and Protect Against Gnawing Animals
Next, use sharp pruning shears to prune off one to three lower branches. Transplanting is shocking to the tree's system and if you prune off some lower branches the tree does not need to exert as much energy to survive. Wrap the trunk of the tree to protect it against vermin and other gnawing animals. There are multiple types of tree guards to consider.
You won't know whether or not the transplant was successful until the spring. Keep checking on the tree to ensure that the props are still holding it properly and that nothing is causing it any damage.
Tip: If your oak tree is older or bigger than recommended, you should begin to prune the roots starting the spring before transplant. Bigger trees have large complicated root systems that can be very tricky to move. In the spring, take a sharp shovel and begin digging around the outer roots and carefully cutting them back. As the spring and the summer progress, continue pruning the roots, only taking off a few inches each time to gradually move the root system closer and closer to the trunk. This will make them more manageable for the winter transplant.