Container Gardening

Sharon Lance
Adams County Master Gardener

One of the most exciting and versatile kinds of gardening, one which seems to grow in popularity year after year, is container gardening. Whether you live on a farm in the country, on a small plot of land in a suburban subdivision or in an urban apartment, there is always room for container gardens. And they are easy; following just a few simple guidelines will produce blooming creations that will delight you all summer.

Location: Before you purchase any plant materials, consider your location; it is one of the most important factors for good container gardening. Plants can be grown in sun, part-sun, part-shade or shade, so make sure the plants you purchase match the lighting requirements where they will be planted. If you are combining different plants in a single container or grouping several containers together at the same site, make sure they share similar light requirements. Do not mix plants that require sun with those that do well only in shady areas. Make sure, too, that your plants share the same watering needs.

Containers: When it comes time to select a container, let your imagination go. Anything that has room for root growth and provides good drainage can be made into a unique and interesting container. More common are terra cotta or unglazed pots which come in many sizes and shapes and are usually orange in color. The pots are heavy and dry out faster than other materials. Glazed clay pots come in many colors and are less porous than unglazed pots thus holding moisture better. Both types are breakable. Pots are also made from nonporous plastic and fiberglass, which cut down on evaporation and hold moisture longer in the soil. They are also lightweight, which makes them easier to move around.

In addition, there are wooden containers, which are usually made of rot-resistance redwood or cedar. They are heavy, durable and do well in cold weather. Wooden containers provide good soil insulation, keeping roots cooler and providing less evaporation than terra cotta. Consider applying a preservative—one that will not harm your plants--to the wood before you plant. There are also containers made from metal, concrete, and other components that may appeal to your taste.

Before planting in terra cotta pots, soak them in water for 10-15 minutes to prevent the clay from absorbing moisture from the soil mix. If you are using old pots, clean them thoroughly to remove any salt deposits and rinse with a 10% bleach solution to reduce chances of disease. Consider how the container drains, and, if necessary, drill drainage holes in the bottom. Good drainage will eliminate water build up in the bottom of the pot, which can lead to root rot and early death of the plant. Also, keep in mind that smaller containers need more frequent watering than larger ones.

Plants: You can grow plants from seeds. If you do, follow the care requirements on the seed packets. If you purchase potted plants, care requirements are usually stated on the plastic stakes included with the plant. These stakes provide the plant name and characteristics which may include lighting, watering, width, height and fertilization requirements. I’ve often kept these stakes until the end of the season to judge how the plant has performed. Then I have plant identification to reference to see if I want to use that same plant in my garden again or to recommend it to a friend.

Soil: The drainage, water-holding ability and growing conditions in a container are different from your regular garden. Use ready-to-use potting mixes. Most contain basically the same ingredients; perlite and/or vermiculite mixed with peat moss. Some mixes have fertilizer added and may even have water-holding polymers which help reduce water needs. To save time and guesswork applying fertilizer, mix slow-release fertilizer into the soil at planting time. Make sure to follow the manufacturer’s directions.

When you fill your containers with potting soil, leave a one to two inch gap for watering between the surface of the soil and the top of the container. Do not use yard or garden soil in a container because it tends to compact and roots cannot penetrate the soil.

Planting the Container Garden: Consider the three basic plant shapes for a successful looking container garden: vertical, trailing and filler plants. Vertical plants (dwarf papyrus, ornamental grasses) are usually tall and narrow and should be planted in the center of the container. Trailing plants (petunia, sweet potato vine) anchor the container and soften the look. Filler plants (coleus, geranium) fill in the remaining spaces between the vertical and the trailing plants and are usually only medium sized. Filler plants can repeat the color of the vertical or cascading plant.

When you are ready to plant, remove your plants from their containers, set them on the top of the planting soil and move them around until you decide where you would like to place them in the container. I have found many prepotted plants to be root bound, so before I plant them I usually cut or tear a scant quarter inch off the bottom of the root ball to break up the roots and enable them to spread out in the soil.

Using your hands or a trowel, dig a hole large enough for the root of the plant, slip in the plant and firm the soil down around it with the edges of your finger. Bury the plant deep enough to not allow the root ball to rise above the soil level. After planting, cover the top of the soil with mulch to help keep in the moisture. Water thoroughly by using a sprinkler hose or watering can. To encourage continual flowering during the growing season, cut off or deadhead flowers past their prime.

Container gardening encourages experimentation. You can combine plants in ways that you would never think to do in a regular garden setting because you can more carefully monitor their light, water and nutrient needs. Planting in containers is a great way to introduce children to gardening by providing them the opportunity to create a container for themselves or as a gift for a grandparent, neighbor, or friend. Container gardening can do all the things that in-ground gardening can do and even more.

So why not resolve this year to plant a container garden. With just a little bit of effort, you will be rewarded with a beautiful garden that will bring you joy all summer long.

Read other articles on gardening techniques

Read other articles by Sharon Lance