The Maple looks like it has a different problem. They don't suffer too much from drying out a bit but the Ilex reacts immediately. The maple could have fungal issues but it is important to make sure there is no insect attack on the very young spring buds which can lead to other complications later. In Australia we have a very common problem with palmatums on the young shoots which is caused by a thrips. It is almost microscopic and attacks the leaves before they open. Black stem on A palmatum is often caused by a lack of proper regular repotting and is not necessarily a disease. You will need to do some research to find out exactly what is going on there. We are in autumn here as well. If it does not get too cold there for a couple of months yet, it is quite ok to repot deciduous trees just as the last few leaves are falling off for the year. I have already repotted a few. I recommend that if you can do it, you repot the Ilex now (when the leaves are yellow) by cutting off at least 50% of the roots and teasing out the remainder properly. The clay I was referring to is akadama or some similar red volcanic clay which I'm sure you have if there are mountains or hills in your area. Maybe try some local soil suppliers. If that is not possible, you can get away with sand/humus (peat moss is quite good) mixtures. You can substitute lava for sand if you cannot get silica sand but make sure the pH is not too high. (adding peat moss will fix it). Also make sure you sieve all the dust out of everything you use and use particles of around 1-3 mm with perhaps 3 to 5mm on the bottom of the pot. If you remember that the deciduous Ilex are native to marshes or wet places it will give you an idea of what they require. It will be difficult to grow serrata if you cannot water when it needs it - which is every day and 2 or 3 times when it's hot.I have another thread about my maples.. do you think is a similar issue or something different?
Acer fungal issues - Again
I have 3 acer palmatums affected by fungus. The leaves got burned (normal, is end of summer), the most burned ones fell off, and from those points new leaves sprouted.. but now, the younger leaves got burned in the tips too, and stopped their growth. But do you suggest? Thank you in advance! 1)...www.bonsainut.com
The problem with “slip-potting” a pot-bound tree like yours is that it won’t likely grow roots into the new soil, and the core of the root ball is still going to dry out.What would you do right now? We are entering fall.