Spider Plants should be watered relatively infrequently, as the plants like to dry out occasionally between watering. The easiest way to tell if a plant needs water is by the weight of the container. If the container is heavy and the foliage is upright, chances are good the plant doesn’t need water, whereas a light planter and limp foliage mean the plant needs some water. Sometimes, water pours out of the container without being retained by the soil. Soaking the dry potting soil in a small dish or saucer can be a helpful way to solve this problem. If you’re unsure, it is always better to let the plant go dry instead of drenching it with water.