What many people do not realize is that too much water is just as bad as too little.
Roots need both water and oxygen, and when surrounded by water, they cannot take up oxygen.
Plants can not tolerate soil that is continuously saturated with water, unless it is a bog plant.
Under continuously wet conditions the roots of the plant will rot and even though the soil is moist, the plant can not take up nutrients and will wilt.
If a plant has wilted make sure the soil is dry before watering it.
If you place your hand over the top of a pot with the plant between your fingers and turn it upside down and tap the edge of the pot on a table edge, the soil should slide out of the pot in your hand.
What you should see are pale white roots coming out of the soil.
If the roots look brown and rotten looking you have been keeping the plant to wet.
There are many factors which can influence how often a plant will need water.
A small plant in a large pot will not need watering as often as a large plant in a small pot.
Clay pots are more porous than plastic pots and because of this they loose water faster.
Also, some soils hold water better than others.
When plants are actively growing in the spring and summer they will need to be watered more than the winter months when they are somewhat dormant.
The way I determine if a plant needs water is to touch the soil, stick your finger into the first inch of the soil in the pot.
If the soil is moist do not water.
If it feels dry to the touch water it.
Water the plant till water drains through the pot if it has drain holes in it, but do not let the pot sit in a saucer of standing water.
If you have a problem getting to the soil because of the plant lift the pot if it is lighter than normal it probably needs water.
Some people tap the side of the pot, if the tap sounds dull the soil is moist and if it sounds hollow the soil is dry.
By carefully observing the soil, you may be able to tell dryness from the color of the soil.
Soil that is dry has a very light color compared to a darker color for soil that is moist.
Plants that receive a lot of sunshine will require water more frequently than ones that are in shady areas.
A healthy root system is the basis for a healthy plant.
Water wisely.