Our fifty year old Japanese Maple

Question: The tips of the end of the branches of our Japanese Maple have been dying during the last two seasons. I noted this spring that there is moss growing in multiple places on its trunk and branches (photo attached)
What can I do?
Thanks,

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied April 03, 2024, 10:59 AM EDT
response: Hi,  Our first thought was that it looked really beautiful and sculptural with the shape and the moss, however if it is struggling to leaf out, that is probably an indication of stress.  To help us further and give you an accurate recommendation we would need some more photos and of better clarity. The one you provided is too blurry to assess anything. If you can take a photo of the branch tips or leaf buds that would be good. You can hold a piece of paper behind it so the camera can focus on the buds clearly. Also a photo of the root flare or where the trunk of the tree connects to the ground, and one of the overall tree and surround space.  Japanese maples are just starting to leaf out so it may be early still to tell if the branch tips are dead. They can get Botryosphaeria canker when stressed. So if they get too much sun, the roots stay too wet, or stressed from drought they can show twig and branch die back from Botryosphaeria. This is a natural soil borne fungus that takes advantage of stressed plants. It infects the plant tissue girdling the branch and causing dieback.  There isn't a cure for it but to help remedy the severity you can lessen the stress of the plant and prune out any dead or wilting branches to healthy wood. This will be easier to do once it hopefully shoes some leaves. Plants can still live for a long time with Botryosphaeria.  Virginia Tech has a extensive publication you can read and view photos of what to look for when pruning. Our webpage that explains Botryosphaeria on Rhododendrons would also be relevant for Japanese Maples. You can send additional photos of the tree and we can help rule out other environmental factors that may be causing its decline. Feel free to attach them directly to this response.  Emily

responder: The Question Asker Replied April 03, 2024, 4:10 PM EDT
response: Japanese Maple3 of 3 Thanks so much,TedOn Wed, Apr 3, 2024 at 10:59 AM Ask Extension <<personal data hidden>> wrote:

responder: The Question Asker Replied April 03, 2024, 4:10 PM EDT
response: Japanese Maple Tree2 of 3 On Wed, Apr 3, 2024 at 10:59 AM Ask Extension <<personal data hidden>> wrote:

responder: The Question Asker Replied April 03, 2024, 4:10 PM EDT
response: Hi Emily, Thanks for the information. The tree faces north and west. I hope these photos are helpful. Only my photography is worse than my gardening. 1 of 3On Wed, Apr 3, 2024 at 10:59 AM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied April 04, 2024, 10:14 AM EDT
response: Hi Ted,  Much better pictures! You did great!  Is there by chance a downspout that is has an outlet nearby?  It does look like the tree is stressed in those conditions and even though has grown for a number of years there, it may have reached its pinnacle. It has limited root room with the surround pavement. Also that pavement will heat up in the summer and with the roots being under and surrounded by it, that will cause heat stress on them and overall stress to the tree.  The close proximity to the walls of the house with restricted air flow (probably why there is so much moss growth), and reflective summer heat is causing stress as well.  We can notice a small population of Japanese Maple Scale at the bottom of the trunk. It isn't abundant so for now, you can just monitor the population. Natural predators may take care of it, or you can gently try to scrape it off with a old tooth brush or similar soft bristle. This has probably moved in due to the stressful conditions. The trunk does look like it is mulched too high or potentially planted too deeply. Trunks on trees need to flare out like the stem of a wine glass. You can read more about it on our blog post "Free the Flare" and try to dig out some of the mulch around the base.  All of these factors could be causing stress to the plant and inviting the Botryosphaeria fungal infection. What we recommended before and the information we gave about pruning out any dead branches (you'll be able to tell as it leafs out more) to the healthy wood. The inner bark may have some dark spots and you want to cut it out until the inner branches look all white and healthy. Also just trying to limit any stress. So making sure to free the root flare, keep it watered in times of drought, and if there is a downspout you can try to extend to outside the bed. Just enjoy the tree and its sculptural qualities as it still lives. It wouldn't make sense and would mostly likely be nearly impossible to have it moved at this point (and probably pretty expensive to do so from a trained professional). Let us know if you have further questions.  Emily

responder: The Question Asker Replied April 04, 2024, 10:51 AM EDT
response: Hi Emily, Thanks so much for taking the time to relay so much info. In 2019 when we re-roofed our house, we had the downspout that dumped water there removed. Seemed like a good idea at the time.We considered moving it years ago and it was ridiculously expensive.I will do what I can, as you recommended, to reduce its stress, and we'll enjoy it.Thanks,TedOn Thu, Apr 4, 2024 at 10:14 AM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied April 04, 2024, 12:02 PM EDT
response: oh good - however for the years it was outlet into that space it may have added to the stress.  Good luck!