Potted plants require regular watering, and it is important to understand the needs of each plant in your home. Water needs vary, depending on the variety and size of the plant, the size and material of the pot and the location. As a rule, allow the top third of the soil to slightly dry out before watering. For example, the top 2 inches of a 6-inch pot and the top inch of smaller pots should be dry.
Many plants do best when water reaches the deepest parts of the soil. The "old-fashioned" way to water plants is to pour tepid water onto the soil from the top. Another way of top watering is to dunk your plants. Fill a sink or a bucket with water, but don't use cold water, as it can causes leaf spotting and root damage. Place the plant into the bucket and leave it until all bubbling stops.
There are many types of plants that can be dunked, or do better when watered from below. One of these plants is the African violet; top watering mars them, leading to rot. Use tray watering, or the wicking system, to water any plants that may be susceptible to crown rot. The preferred way to water from below is to fill a saucer or other drainless, shallow container with tepid water and place the plant in the saucer. The water is pulled up into the soil by wicking. Always remove your plants after watering; the plant's roots should not sit in standing water for too long.
Watering aids that can be helpful include a slow-release water ball, a polymer to mix with plant soil that causes water retention and a mister for misting flowers and foliage. An electronic moisture meter can measure the dampness of the soil in the root ball. Self-watering pots can help to extend the time between waterings, but they should only be used for plants that require constant moisture.