It all depends. Some plants like to have moist soil, so you should water when the top one inch of soil is dry to the touch. Roses in the ground and blooming annuals like petunias and begonias may need water once a week if the weather is cloudy or every day if the weather is hot. Some plants like dry soil. This would be plants with gray foliage or succulents and cacti. They may survive on rainfall alone, depending on where you live. Plants in pots need a lot more water and plants in the sun dry out sooner than those in the shade. The general rule of green thumb is to feel the soil by poking a bare finger down. Water when the top one or two inches is dry. Be sure the water drains from the holes of potted plants. Keep growing, Marianne Binetti