Hi maple lovers, I am new to Japanese maples and would like to learn how to identify problems I am in zone 9b and recently there are two heat waves in last month like 90+ degrees. So I water my maples everyday while keep them in 3h morning sun locations. My Amagi Shiguri now looks like sick as in the picture. How can I tell from the leaves whether they are due to heats or overwatering or something else ? Thanks a lot
Good morning @1cc, the reticulated maples do not like the hot sun. They need far more shade than the the plain leafed maples in my experience.m, especially the paler coloured varieties. Unless in a pot, I would not water every day. Every few days, even in high temperatures is fine. So IMO I would aim at more shade to help your Amagi Shigure.
yes, definitely looks like a result of excessive heat on a tree that should only be getting an hour or two of morning sun. These record temps. globally are really putting a number of japanese maple varieties to the test. Also, with these very high temps, personally I would not keep a container grown maple in a plastic pot. The outside of the pot becomes like a warm simmering oven that causes so much stress on the roots. And Clay also will do the same unless it is a very thick diameter. Although cement is heavy and pricey, it definitely is the best option in my opinion. Especially if you have containers in the full sun.
Thanks a lot Acerholic and Otto, your expertise are very appreciated. Yes my reticulated maples are the worst (Amagi Shiguri and Purple Ghost) but all the other 10+ maples are fine (except orange dream) I also have a baby Tyler, in an extremely shady area covered by other trees, and it is doing even better, keeps the pink well and didn't have any leaves damage so far. They are all in plastic pots. The pots however are covered by Azalea bushes in the shade.. Let me see if I can move more plants to cover them. So what will a overwater maple looks like? Google search tells "yellow and backend leaves" is difficult to image.. Have you guys seen a overwater one?
Yellowing of the leaves and root rot, and in the case of the darker foliage maples, a pale foliage not normally seen. Re root rot, then the tree will lose its vigour, with black tips to the leaves and for what you might think for no reason at all as you are watering it regularly it subsequently dies. This often happens in poorly drained soils btw, ie Clay. Re Tyler, do you mean Taylor?? If it is, then I have found it to be a very weak cultivar. I had two that died, so no more. Friends have had the same outcome. Yes a very pretty tree in Spring, hence a lot on display at garden centres etc etc in April to tempt customers. I totally agree with Otto about pot colours. Lighter shades reflect heat and the black absorbs it. So in extreme Summer temps, delicate maples roots will cook. It will be a good idea to also move Orange Dream to some shade. It is a lovely tree but suffers in the Summer sunshine.
unfortunately Amagi shigure... https://forums.botanicalgarden.ubc.ca/threads/acer-palmatum-buyer-beware.63480/page-2
