I have a new Hoshi kuzu sapling in a pot on the Western side of the house in the Oakland Hills. From time to time the icy cold foggy air blows up the canyon hitting the house and deck. About a month ago the fog burned the tips of all the leaves on my new tree. Should I cut the dead foliage off? Will the tree die? Should I move it into the house where there is good light?
Hi Leslums: You may want to read this thread below titled Scorched!. http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=3027 I am not so sure it was the cold air that hurt your Maple as with fog after a warm spell we are in danger of getting hit by Anthracnose. Does Anthracnose hit Japanese Maples? Yes, it can. Especially the small leafed dwarf forms when the leaves are the most tender. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7420.html What should you do? Leave the plant alone if the stems have not also been affected. With a little warmer weather you should have new growth buds appear and then you will have a flush of new growth. You will have to be extra careful that the new growth does not get scorched again soon. You should be okay for a while with you being up on the hill but you may want to move your plant somewhere else to protect it when you know it will be foggy again soon after a warm spell. Do not bring the plant into the house unless you really have to and then for only a few hours. Dramatic temperature changes may adversely affect your plant more so than the fog can but it is the series of fungi that attack in cooler, wet conditions that can hurt you the most. Even cool winds can scorch young Maple leaves so keep that in mind when placing your Maple where you want it. Try to keep the Maple away from the direction the winds are originating from. If you have primarily winds out of the Northwest do not place your Maple in a Western exposure. If the winds are coming in from the Southeast then a Northern exposure may be best for you. Jim