URBANA, Ill. – Many would-be gardeners may be discouraged by a lack of available outdoor space. The solution may be container gardening, according to University of Illinois Extension educator Ken Johnson.
“Anything that you can grow in the garden can also be grown in a container,” Johnson says. “You just need to provide your plants with a few basic needs: a container, growing media, water, nutrients, and light.”
When growing plants in a container, a number of factors should be considered.
Anything that can hold soil and has drainage can be used to grow plants. According to Johnson, this can be a pot from the store, a bucket, a milk carton, or even a shoe. “But if you’re going to be growing something you plan on eating, it may be best to stick to a more traditional pot,” Johnson suggests.
Containers must have drainage holes, but these can be added easily to any container type. It is also important to consider the size of the plant, and to ensure that the container will offer ample space for the plant when fully grown.
When choosing a growing medium for your container, the best choice is something that is well aerated, drains well, and is able to hold enough water for the plant to grow.
“The best and most common growing media for containers are called soil-less media, because they don’t actually contain any soil,” Johnson says. “They are made up of things like peat, vermiculite, bark, coconut coir, and perlite.” These can be purchased commercially as all-purpose potting mixes, or you can make your own.
Because soil in containers dries out much faster than soil in the ground, it is important to keep containers well-watered. “Plants vary in their water requirements, but a general rule of thumb is that plants should be watered when the top inch or so of your growing medium feels dry,” Johnson says.
Water plants thoroughly, until water starts to trickle out of the drainage holes. In warm, dry weather, containers may need to be watered more than once a day. Unglazed ceramic pots also tend to dry out faster than glazed or plastic pots.
Johnson explains that soil-less media are usually low in nutrients. Because of this, container-grown plants may need to be fertilized at some point. “You can use either slow release or liquid fertilizers,” he says. Make sure to follow the directions on the label when applying fertilizers, to avoid damage to your plants.
It is also important to know the light requirements of container-grown plants (i.e., full sun, partial shade, or shade). Most vegetables and annual flowers need at least six hours of full sun to grow properly. Other plants can be damaged by too much bright light. Most plants come with labels that indicate their light requirements.
Before planting, it is recommended that growing media be thoroughly moistened. Johnson notes, “Leave about one inch of space between the rim of your container and the soil. This will help prevent water from overflowing your container.”
If growing plants from seed, plant at the depth indicated on the seed package. “It is usually a good idea to overseed and then thin the seedlings to the spacing indicated on the package, as not all seeds may germinate,” Johnson says. “If growing from transplants, use plants that look healthy and make sure to thoroughly water your container after they have been planted.”
To learn more about container gardening check out the U of I Extension’s Successful Container Gardens website at https://extension.illinois.edu/containergardening.