Money trees should be watered at least once a week. Money trees thrive in slightly moist soil and should be watered when the soil feels slightly dry. A light misting with a water bottle every few days helps keep them properly watered.
Guide to Houseplants recommends watering indoor money trees until water seeps out of the drainage holes at the bottom of the pot, and then waiting to water the plant again until the first two inches of soil are dry. Outdoor money trees thrive in areas near water because the soil is less likely to dry out. Money trees planted away from water generally require about an inch of water per week. However, they may require more in hot, dry weather.