Containers filled with blooming flowers and bold foliage can bring a burst of color to a patio, deck or porch. And for some apartment and condo dwellers, containers may be the only way to grow.
The challenge is water. Plants in containers don't have room to stretch out their roots to search for water like plants in the ground do. To complicate matters, a plant's requirements for water change as the plant matures and the temperatures climb.
In the spring, when plants are just starting out, most containers typically need to be watered about every four days. (If you find yourself watering much more often, you should think about moving your plants to a larger container.)
However, in the heat of summer, with mature plants filling the container, plants might need to be watered daily.
To figure out whether you need to water, do the finger test: Stick your pointer finger into the soil up to the first knuckle. The potting soil should be just wet enough that some of it sticks to your finger.
Of course, you can buy a soil-moisture indicator at the garden center. Luckily, most of them work well. The simplest and least expensive of these are the clay figurines that turn darker red when the soil is moist, but turn orange as the soil dries out.
You also can buy potting soils and additives that help hold the moisture, but a good potting soil must balance water retention and aeration.
(Soil from your back yard holds too much water, and therefore allows too little space for air, when used in a container. That's why potting soils are essential in containers.)