One of the biggest challenges for gardeners interested in container gardening is choosing the right type of container to grow both edibles and ornamentals. When you visit your local garden center or hardware store, you may be overwhelmed by the sheer variety of container materials from plastic and terra-cotta to stoneware and concrete. Below are some of my tips for finding a pot that will help your container plants thrive.
Drainage Is Key
Before considering the material of your container, I strongly recommend you find one with holes in the base for water drainage. Drainage is a critical element of container gardening. Without an outlet, water will accumulate in your pot and lead to root rot, which will damage or kill your plants over time. While you can often create your own drainage holes in containers, it can be a pain in the neck and can actually weaken some ceramic containers.
Choose Your Material
Two of the most common types of garden containers are terra-cotta and plastic. Both have advantages and disadvantages, and here are some of my thoughts on each to help you choose one to suit your growing purposes.
The ubiquitous mental image of container gardening inevitably includes these classic dark-orange clay planters. Unglazed terra-cotta pots are attractive and come in a range of sizes and shapes. Their porous nature allows water and air to gradually pass through, meaning root systems get the moisture and oxygen they need while also having the ability to wick away excess water. Their thickness helps insulate the soil, keeping root systems free of rapid temperature swings, which can be detrimental.
While container gardeners often reach for terra-cotta pots, keep in mind they’re relatively fragile. During cold spells, the moisture in the walls can freeze and expand, causing the pot to chip or crack. Terra-cotta users also frequently complain about the white crusty residue that builds up on the exterior of the pots caused by salts in the local water or fertilizers leaching through the porous walls. This residue can be removed with a diluted vinegar solution, a scrub brush and some elbow grease.
Plastic containers have the advantage of being both cheap and lightweight, though there are some significant issues with plastics. Because we’re discussing outdoor usage, plastic containers will be exposed to a regular dose of UV rays, which can discolor and weaken many plastics, turning them fragile and brittle within a few seasons. UV-resistant containers are available and are recommended over traditional plastic containers.
Unlike the insulated walls of terra-cotta, plastic pots have very thin walls that can quickly cool down or heat up depending on both the size of the planter and color of the plastic. If you’re in a warm climate, like South Carolina where I live, avoid using dark-colored plastic containers in the summer because they can overheat and dry out the soil quickly.