Answer: Some foliage browning along the edges can be attributed to underwatering, but there are also cases where this is a symptom of overwatering as well. It is important to water a newly planted tree or shrub regularly, helping to supplement rain so that the soil is kept moist during the establishment phase. This would not be saturated or soggy wet, however.
Since this plant (Aesculus x carnea `O`Neill Red`) would do best in a moist yet well drained soil, it would certainly be sensitive to overwatering. Use your fingers to dig down into the soil an inch or two to see if you need to water or not. When you water, water deeply rather than a daily light sprinkling. Also, in case this is some sort of fungal problem, avoid wetting the leaves when you water.
Q&A Library Searching Tips