Trees that have been girdled due to animals or other types of damage will usually require a bridge graft. This is a good repair solution that can be attempted to salvage trees that are already established. The process involves the use of cambium layers in the girdled area to rejuvenate the flow of nutrients. Tree wounds heal differently compared to human ones so without the bridge graft, it’s safe to say that the damaged tree won’t be able to recover.
The first thing that needs to be done before making a bridge graft for the tree is to figure out whether it’s actually needed. Keep in mind that it takes quite a considerable amount of effort to repair a tree using this method. It’s recommended to use bridge-grafting only for those special trees that are really badly damaged. Unless the wound is large enough, the entire process won’t offer much help to the healing process. Early spring is the best time for bridge grafts because you need to work when the bark is actively growing.
1. Materials Needed
Grafting requires a few materials to complete the process. Aside from previously collected scions (bridge wood), you need some special wax used for graft protection. The wound will require a bit of trimming so it’s recommended to have a sharp knife ready. A dowel or short block of wood is needed and you should also include brads to keep the scions in place.
2. Preparing the Tree Wound
The first step for making a bridge graft involves preparing the tree wound for the process. All that damaged bark needs to be trimmed back. The girdled area needs to be reshaped to end up with a smooth edge. It’s important to follow the shape of the tree wound and get rid of any loose bark to reach healthy tissue. Make some cuts at the top and bottom of the wound according to the size of the scions used.
3. Shaping and Placing the Scion
The scion needs to be shaped using the knife. Make a long cut at each end and a shorter one in the back of the bridge wood. There’s no need to leave buds in place. You should end up with a scion that’s a bit longer than the girdled area. Make sure you place the bridge wood quickly before the cut surfaces start to dry.
While you can remove the buds on the scion, it’s very important to check their position to avoid the placement of an inverted scion. Put the bridge wood with the long cut against the wood and fasten it with the help of the brads. Scions are inserted in the slots created in the wounded area and should bow slightly outward.
Next, it’s time to add the dowel in the mid-area of the scion to keep the grafts sturdy against tree swaying. You can take off the wood piece once the scion is properly tacked. To finish the process, you only need to add the grafting wax or emulsion used for covering the nailed scions. Don’t forget this step to ensure the bridge graft doesn’t dry out.