Answer: Water stress can cause the leaf symptoms, but so can insects and disease so I can't really diagnose the problem with your maples. Aphids can feed on the foliage which can cause them to curl and lack color. This year watch the leaves for insect pests and hose them off if you find them. Japanese maples like moist soil but not soggy wet soil. Try watering them deeply once each week during the growing season. You can feed your trees with a 10-10-10 general purpose fertilizer in amounts as listed on the label. Hope this helps!
Q&A Library Searching Tips