Containers have always been essential for gardening on patios, decks, porches, and balconies--any place where soil isn't present. But they're also being added to landscapes, either as a focal point within the garden or as a way to let gardeners grow plants that wouldn't otherwise thrive in the native soil or that need special care.

Almost anything that can be grown in the ground can be grown in a container, and sometimes a container is a better choice. Tiny rock garden plants can be brought up to eye level where they can best be enjoyed. Vegetables can be moved to the sunniest spots in the yard throughout the growing season. Trees and shrubs can be nestled in among other plants, even if they don't have the same care requirements.

Containers are great if you want to grow specialty plants, such as tropicals or succulents, especially in areas where these plants wouldn't survive the winter outside. You can bring both plant and container into a sheltered area until spring.

There are some rules for container gardening. You need to choose the right pot for the overall size and shape of the plant. You also need to find the right potting mix. Finally, you need to pay attention to water and fertilizer needs. Because the roots of container-grown plants can't get food and water from ground soil, you're the only source of these essentials.