I've had an acer rubrum Red Maple for 3 months in a pot which has been growing vigorously. The growth during spring and early summer has been so vigorous that I've had to trim the tree regularly. Now in late summer I've noticed new leaves are sprouting quickly but they've also quickly curl down and die. They are light green in colour which were in contrast to the usual red which then turn to green. Is it some kind of fungal infestation? Some weeks ago I noticed some fungus on the soil surface which I just pulled and threw away. I then added a very thin layer of new soil on top and I haven't seen the fungus since. The weather has not been hot for a long time here in Sydney, in fact it has rained a lot. I also water the tree daily.