Plants emerging from terra cotta or plastic pots, windowboxes, or hanging baskets are common refrains, and they make great growing vessels. But let's also think outside the box.

Practically any type of container can be used to grow plants as long as it holds soil, can drain water, and is large enough to accommodate the plants you're growing. You are only limited by your imagination and access to such places as attics, garages, and recycling centers. Consider these planter possibilities: buckets, tubs, beach pails, ceramic bowls, teapots, stacks of old tires, crocks, baskets, ceramic flue tiles, half wooden barrels, crates, sinks and bathtubs, toys (football helmet, dump truck, wagon).

Better yet, have your students brainstorm their own list. Here are some things to consider when choosing containers:

• The larger the container, the larger the plant (or number of plants) you can grow to maturity. Soil depth is also important. Deep-rooted plants, such as tomatoes, need at least 12 inches of soil, but radishes can get by with as little as 4 inches. Windowboxes should be at least 9 inches deep.
  


• Think about drainage and porosity when you choose containers. For plants to have healthy roots, soil needs to drain well. If a container lacks holes or other methods for drainage, water can build up and roots can smother. On the other hand, if a container dries out too quickly, plants can suffer. The materials you choose may depend on your climate, the plants you're growing, and your willingness to water.



• Note: Avoid using containers made of pressure-treated wood, which is impregnated with toxic chemicals that can harm plants and people. If you build your own wooden boxes, use rot-resistant wood, such as cedar, or treat your container with an exterior grade paint or opaque stain to protect it from rotting.