Best Containers for Edibles
It is important to choose the right container for planting edibles
When we select a container for growing an edible garden we need to consider which edibles we plan to grow, where the container garden will be positioned, as well as the specific qualities of the container. Just about anything can be used for a container as long as we understand how the container construction and material may affect the plants.
Container Size
The size of the container you choose is very important. Bigger is always better since a large volume of soil will retain moisture best. And many edibles, especially tomatoes, set very deep roots. If your container is too small and restricts root growth production will be reduced. Taller plants can also topple your container if it is too small or too lightweight. Many herbs are shallow rooted and will do well in small shallow containers. Ideally 12 inches deep but some herbs and greens will do fine in an 8 inch deep trough where roots can spread out a bit.
Container Placement
Container gardens require closer attention than gardens in the ground. Frequent watering will be necessary to maintain soil moisture, so be sure your containers are convenient to either your watering hose or for lugging watering cans. Monitoring for pests is easiest when containers are on your deck, patio, or frequently passed area. You may also want frequently used cooking herbs to be right outside the kitchen door.
Typically we would grow full sun plants in full sun and shade plants in shade. But when it comes to edibles we may be growing seasonally and find the need to adapt to changing conditions. Our cool season greens may not fare well in an unusually hot and dry period and will need to be moved into the shade or sheltered in late or early frosts. Consider what you are growing and when and perhaps choosing a container easily moved for certain edibles. I grow my cool season greens in easy to manage trough planters that I frequently move in and out of the sun as needed.
Container Material and Construction
Potting containers are made of many types of material that will affect how frequently you need to water. Porous containers such as clay and unglazed terracotta will allow the soil to loose moisture quickly, especially with smaller pots. Wood and pressed fiber containers are semi porous and will hold moisture better. Glazed potter and plastic or resin containers are non-porous and will allow your soil to retain moisture the longest, but good drainage holes for excess water to drain off is essential.
Other specific considerations:
Metal containers and dark colored containers of any material will heat up quickly in hot sun, potentially damaging plants and roots. In hot climates these containers should be avoided in full sun or be portable enough to move into the shade.
Unglazed terracotta stays cool in the heat, but of course will require frequent watering.
Resin and plastic containers are lightweight and very easy to move as necessary. These containers are looking more appealing all the time and are reasonably priced.
Wood tubs, planters, troughs and window boxes are great for edibles but make sure they are food safe. Treated wood can leach chemicals into the soil that can not only be harmful to plants but may be taken up by the roots to “feed” your vegetables or fruit. If you make your own containers from treated wood be sure to use a liner insert.
Wood and metal containers both require maintenance. Cedar and redwood are the most rot resistant woods, but most any wood will require paint or stain to prevent rotting. Be sure to use non toxic coatings and consider using a liner insert to reduce moisture in the wood. Metal containers will eventually rust outdoors. You may want to clear seal them to seal and protect the metal, but also use liner inserts for your plants to keep moisture from the metal and to prevent rust and sealing chemicals from contacting your soil.
And of course, it never hurts to plant your edibles in a beautiful to look at container!