You can gauge roughly if your plants need water by sticking your finger into the soil up to your knuckle. If soil doesn't stick to your finger, you need to water. Use an inexpensive moisture meter for large container plants, recommends the Colorado State University Cooperative Extension.
About this Author
Kathryn Keep is an eco consultant and full time mother. She is a graduate student studying ecology. Her favorite topics are environmental issues, alternative health, home decorating, green building and general sustainable living.