Introduction to Container Gardening

Posted at 9:55am on May 05, 2017

Container gardening is a diverse subject. Talks can range from raised bed gardens to house plants. Here, I want to give an introduction to the benefits of this form of gardening, and the various styles that are available. Since a book could be written about vegetable containers alone, I plan to go into detail about each type in later blogs. First, what is considered a container? Seems self explanatory, but really there is a wide variety available for gardening purposes. The first thing most bring to mind is a traditional clay pot. These can be a variety of shapes, sizes, and materials. All types of traditional pots will have a hole through the bottom for drainage. Another style of container is known as a "self-watering" or "self-contained" pot. This design is the most basic form of hydroponics. Here, water does not drain freely from the container. There is a small well contained at the base of the pot so that the soil or roots can pull up/wick moisture. Lastly, raised beds are considered a container as well. They function like a very large traditional planter constructed of an outer frame with a layer sand or rock at the base to increase drainage and reduce compaction.

What are the benefits of these types of planters?

Each design has its own unique pros and cons, but all containers provide the crucial benefit of loose soil, resistant to compaction. It is easy to forget the importance of a healthy root system. We spend so much time focusing on what we can see of the plant that the root system can go unnoticed. A plants root system is the direct reflection of overall health. Higher root development yields greater above ground growth. This is achieved with adequate nutrient availability and easily penetrable growing media. Both of these factors are easy to moderate and control in a container environment. Healthy soil is healthy plants. The goal is loose, well-drained, nutrient rich soil. Don't settle for less, and please NEVER use topsoil. In the case of vegetable gardening containers are the only way to grow. Even in areas with rich tillable soil, a raised bed or large container will almost always yield more per square foot. Large in ground gardening requires stepping around plant root systems to remove weeds and harvest. This means the ground compacts quickly through the season. This leads to slower roots development which will not produce optimum yields. Container gardening also allows for versatility in the use of space. A wide variety of hanging planters, small pots, and wall containers convert tabletops, shelves, and deck rails into places to garden. Using vertical space is a great way to have a garden anywhere.

There are other benefits specific to each style of gardening as well. Traditional pots, for example, provide the greatest about of drainage. Therefore, they are excellent for plants that like it on the dry side. They are also great for areas that get a lot of rain. This is because standing water on a roots system can cause rot. This is especially true in our area. Be careful using a self-contained pot in an exposed area for this reason. In contrast, use self-watering or self-contained pots in areas that are very dry, plants that prefer continuously moist soil, or when growing indoors. Raised beds are an excellent long-term solution to compaction, erosion, and poor soil. For this reason they are perfect for terracing steep inclines or creating a striking look to an entryway. They can also provide tailored soil environments for any plants that do not thrive in your native soil. For example, lavender, pines, and sedum like well drained, semi-sandy soil. This is not available for many homeowners locally. Here in the Mississippi river valley many yards are poorly drained clay which can lead to root rot for many of these types of plants. This makes a raised bed a perfect solution because the soil is customizable.

All this talk about soil... What do I choose?

Tailoring the planting media to botanical variety is an important benefit to container gardening. It is also a crucial step for success. There are two general groups of planting media available: potting mix and potting soil. Potting mixes consist primarily of sphagnum moss or coconut hulls and vermiculite/ perilite (a mineral used for drainage). Their ingredient list does not contain any soil ingredients such as compost or earthworm castings. For this reason it is the lightest weight mix with the greatest amount of drainage and air space. Use these types of mixes (we carry Fertilome Ultimate Potting Mix) for self-contained pots/hydroponics, plants that require maximum drainage, or if water soluble fertilizers are preferred. On the other hand, Potting soil often contains compost, peat, or earthworm castings mixed with a drainage element like perilite or rice hulls (HSU or Dr. Earth potting soil). It is slightly more dense, but still has better drainage than traditional garden soil, and has higher intrinsic nutrient content. These mixes are best for raised bed gardens or in traditional planters when slow release fertilizers are used. In any case, always buy loose, well-drained soil/mixes for containers.

Step By Step: tips for success

1. Choose where to put your container garden. This is most important to decide first since light availability, temperature, and space will all determine the following steps.

2. Choose what to plant. Consider exposure to sunlight, rain water, and relative temperature of the spot, then ask a nursery associate to help find plants which will work well for those conditions. Keep in mind if it is annual or perennial, as frost resistant containers will work better for permanent plantings.

3. Choose a container. Keep in mind what the watering needs are of the chosen plants (full drainage/ needs to dry out between watering or self-contained/ consistently moist) and provide a container which suits this. Winter hardy/ perennial plants should be in raised beds or concrete/weather proof pots that can provide proper insulation to the rood systems.

4. Choose a potting media. Keep in mind the type of container (self contained containers need soiless mix), preferred method of fertilization (slow release or water soluble), density and quality of mix (should be fine textured, loose, and well drained).

5. Fertilize

6. Water, and keep a good eye on watering. Since containers have excellent drainage, they tend to dry out faster. Check all containers daily for the first couple weeks to get an idea of general watering schedule.

7. Add trellises and supports to taller plants. Not only does it look stunning, it can provide support to plants in windy conditions. It is also crucial for container veggies like tomatoes, peas, and beans to provide a greater yield.

Written for The Green Thumbers by Elaine Guthrie 4/23/17