Watering

• Your outdoor potted plants will thrive if you do not allow the soil to become dry. Check the moisture content of the soil twice a day and, if the first inch of the soil is dry, water the plant. Use enough water to moisten the soil ball so that water starts to drip out of the drainage holes. Well-water or rain water does not have any soluble salts that can harm your plants. Tip the drained water out of the drainage container so that the plant pot is standing on a dry surface at all times.
  
  

Choice of Container

• The container you chose for your outdoor potted plants should be large enough to hold the plant and its roots comfortably yet not too small that the soil dries out between waterings. Containers made of porous materials, such as clay or terra-cotta, will soak up the water, taking it from the soil. You can use a plastic liner in a porous container to stop this water absorption. The soil within your container should remain at an even temperature but metal containers will heat up in the hot sun and cool at night, drying the soil and causing the soil temperature to fluctuate. Dark-color containers cause the same problems.
  
  

Drainage

• Poor drainage leads to water-logged soils that leave no air in the soil for root growth. Ensure that your container has multiple drainage holes in its base, drilling them yourself if necessary. Non-porous containers, such as those made from metal and plastic, do not allow air circulation and need larger drainage holes than porous containers.
  
  

Soil

• Use potting soil or a soilless mix for your potted plants for maximum water retention. Garden soil often has clay particles that compact, reducing the oxygen and water available for the plant. Potting soil is porous and slightly acidic, and will hold water and nutrients for a long period of time. Soilless mixes contain the same nutrients as potting soil but are much lighter. They contain peat moss or ground bark to hold the water and nutrients, perlite to create a loose soil and vermiculite to retain water.