AlexKr
Watering frequency depends on a few things. For an average-sized hanging basket in full sun in 90-degree weather, I'd probably water it daily because it is exposed to the air on all sides and dries out very fast. Possibly every other day. Factors that affect that are how densely it's planted, whether it's in sun or shade and the nature of the potting soil. If you wait until the soil is bone dry it will become hydrophobic and water will run down the sides but won't saturate the interior. More hanging baskets fail from drying out than over watering.
Planters and pots are a little different. Assuming they have drainage holes, you should water until water until water runs out the bottom and then the 1" rule is pretty safe but not an absolute. Again, location, temperature and plant size affect watering frequency, as does the type of plant (whether it prefers moist or dry soil). One reason your soil is staying wet could be because the container is too big for the plant(s) and their roots aren't developed enough to fill the container and use the water quickly. In that case, do be conservative until the plant matures or you risk drowning the roots. And certainly water if the plants look distressed or wilted.
As the season progresses, you'll get a sense of how frequently to water based on how the plants respond.
