Knowledgebase
Japanese Maple Dead Branches #198815
Asked July 12, 2014, 5:51 PM EDT
I have a Japanese maple located on the northwest corner of my house that has many dead branches. I think this is from the harsh winter but would appreciate if someone could tell if could possibly be something wrong with the tree. Assuming that this is winter damage I would like to know if I should just prune away the dead branches and hope that the tree recovers. If this is caused by the winter, I would also like to know if there is something I can do to protect the tree from winter damage in the future.
I recently had a soil test completed in the area around this tree and the soil pH was 7.9 and it had optimum P, below optimum K and above optimum Mg. The calcium was 4308 ppm and the CEC was 24.254.
Thanks for your help.
Hamilton County Ohio
Expert Response
Looking at the photos you sent, I would suggest that the damage is consistent with what I have seen after the winter. My Japanese maple showed the same type of damage.
Prune the branches back to the living tissue, where you see new growth coming from the branch. You can do this any time the tree is not frozen. ( not an issue this time of year). The tree should be fine as long as the harsh winters do not continue. Check the trunk of the tree to make sure that there are no cracks or damaged tissue, which will appear as sunken spots in the bark.
Japanese maples like to have soil that is in the neutral to slightly acid range, a pH of less than 7. Your pH is a little high. You could help the tree by adding a layer of organic matter, like compost, and keeping the tree watered during the dry summer.
Most commercial fertilizers contain all the micronutients that are needed unless you are really deficient in one particular one. The CEC will decrease at the soil pH decreases making more nutrients available to the plants. The soil pH can also be decreased using sulfur or Aluminum Sulfate. Follow the directions on the container if you use these.
As for protection to prevent future damage, since the tree is on the northwest corner, you could build a wind break for the tree using stakes and burlap. Place the stakes in a triangle around the tree and fasten the burlap to the stakes. Do this after the tree has lost its leaves in the fall. However, we may not have similar winters in the future. If this is your first year with damage, then it may just be an unusual winter.
If you wish to fertilize to help the tree to recover, do so sparingly. We are in mid summer, so you do not want to push soft growth too late in the season as that sets you up for more damage in the winter. Your soil test would indicate that you would need some fertilizer with Nitrogen and Potassium, with the lower than optimum K.
I am attaching a discussion from the Buckeye Yard and Garden Online about winter damaged plants. Find the link below:
http://bygl.osu.edu/content/litany-winter-injury-thte-winter-2014-continues-0
I hope this has helped you with decisions about your Japanese Maple. If you have other questions that I did not answer, just respond to this email and it will come back to me.
Thanks for using Ask a Master Gardener.
