With all the hot weather this week it is hard to imagine plants being waterlogged within their soil.  However, some home owners take this hot weather in mind and overcompensate watering their trees & shrubs.  Signs of waterlogged roots in plants can show up as leaf scorch or leaf thinning in deciduous plants and tip burn on the candles of evergreens and pines.  In small shrubs and many perennials, too much water will seem like not enough because the plant tends to wilt.  Best bet on whether or not to water is to stick you finger in the soil around and below the plant.  Moist soil is good and should not be re-watered until the area has dried out (but before cracking of the soil).