And don't depend upon rain to water the containers as well as it does your garden. Do be careful not to over-water. Soil that is kept too soggy deprives roots of food and oxygen and will lead to death as surely as a lack of watering. If the top of the soil is never allowed to dry out a bit, you are being too fanatical about watering. If the leaves or stems get mushy, or the leaves curl or get yellow, it could be due to an excess of water.
Moderation is the key.
So, too, with feeding your container plants. If a plant is not doing well, investigate before you pour on the fertilizer. It may be that you are already stunting or killing it with food. Perhaps you have put a shade lover in the sun, or vice versa. May be you have been over-watering.