Most people seem to understand that proper watering of the tropical plants in their home or business is vital to their health and beauty. Few people water indoor tropical plants using the method our maintenance staff has perfected over the years. Plants do need water to survive in pots indoors but the frequency of watering and the volume of water needed is a tricky proposition.
Here’s an important point to consider: plants benefit from drying out between watering. Roots need oxygen and dryer soil has more air pockets than soil that is constantly wet. Plants are susceptible to disease and root rot when the soil is always sodden.
In my experience, people water plants frequently because they believe it’s necessary to do something to insure the plant’s survival. They also err in using too large a volume of water for the plant to use in a two week period.
It’s easy to examine the top of the soil: If the surface is wet, it’s a safe bet the soil will be even wetter deeper in the pot where most of the plant’s roots are. The more roots a plant has, generally the more water transporting ability the plant has. Another method I use frequently is to lift the grower’s pot that holds the plant. The heavier the plant is, usually the wetter the soil is. Also, one can put a finger as deep into the soil as possible; if the soil feels wet, it will need less or no water.
Succulent type plants and plants grown in Hawaiian volcanic rock need very little water bi-weekly. I will add no water to these plants if I determine they’re moderately wet. Conversely, I’ll add up to 1.5 gallons of water to a 6’ tall floor plant in a sunny window if it’s dry. If the plant is left sitting in a few inches of water, it will soak it up over a couple of days.
The last idea to grasp is that the volume of water a plant needs can change with the season and other environmental factors. Plants usually need more water during the winter months because the heating system will encourage transpiration. They will need less during the air conditioner season.