Japanese Maple – Watering Properly

Q: My mother has a Japanese maple which did very well after being planted in the fall of 2000. However, over the last two weeks, the leaves have begun to curl and dry and subsequently fell off the tree. She went to a local nursery for their advice and was told that this problem could be due to either too much water or too little water. Since then, the leaves have continued to turn brown and fall off. Could you give us your opinion?

A: I think the nursery diagnosis was right on the money. The likely reason for the leaf loss is simply that the root ball of the maple never stayed sufficiently wet to establish itself in the soil.

Although it was planted in the fall, the winter was not particularly wet and you might not have watered it very often. Once a root ball becomes dry, it is hard to become re-wet again (it’s called hydrophobic soil at that point). Although the spring and summer were wet this year, my guess is that the root ball is still about the same size as it was when you planted it.

At this point there is nothing much you can do. If the maple contains a bit of stored energy it may leaf out now or wait until next spring. Water the soil around it deeply every week or two and mulch with pine straw under the branches. Keep your fingers crossed and we’ll see what transpires next April.