Containers add interest to decks and patios and are the ideal solution for those who have limited space. While gardening in containers is simple, there are a few key factors to keep in mind. You need to pay special attention to your choice of containers and the soil mix used for the plants. Watering and fertilizing regimes are important, too … and then there are the plants themselves.
Overheated soil is a common cause of many container planting failures. Using appropriate containers can make the difference between a sad and sorry sight, and a planting that says “Wow!” Avoid metal containers. They overheat very quickly. Keep in mind that dark coloured materials absorb heat faster than light colours. Consider using lightweight planters made from one of the new molded polyethylene resins. They withstand all types of weather and are UV sunlight resistant, too. Whatever containers you choose, be sure that they are deep enough to support the plants’ root systems. Most importantly, containers must have drainage holes because the roots have nowhere to go to get away from too much water. Soggy soil causes root rot and that means certain death to most plants. Before you add soil to the container, lay a piece of fine mesh screening in the bottom to prevent the planting mix from washing out through the drainage holes.
Roots require air for growth and transpiration, so it is important that some air pockets remain after the soil has been watered and drained. Don’t use heavy soil from the garden. You’ll get better results with a commercial mix designed especially for container planting. These artificial mixes are made with materials of varying sizes to encourage air pockets, are very absorbent and leave a “reservoir” of moisture in the soil once the water has drained out.
Container plants require more frequent feeding because they generally require more frequent watering. This frequent watering leaches the fertilizer out of the soil more rapidly. Granular time-release fertilizers added to the soil at planting time are convenient and relatively foolproof. Be sure to follow the label directions.
To ensure success, follow these tried and true design principles.
- Odd numbers of plants tend to be more pleasing.
- Stagger plants within the container so they “fill in” better and make for a fuller planting.
- Rows should be about 7.5 cm (3 inches) apart and plants about 15 cm (6 inches) apart.
- Single colours or simple monochromatic combinations are very effective.
- Repeat patterns in and among the containers.
Location, Location, Location
The beauty of gardening in containers is that you can move them around wherever you want them. Just be sure to pay attention to the plants’ cultural needs. Make sure you group plants together that like the same light conditions. For shady spots, try ferns such as sprengerii as well as other foliage house plants. Dwarf hostas, lobelia, coleus, impatiens and fuchsia are all good low light choices. Areas that get full sun most of the day should be planted with plants that can take a lot of heat. The dwarf zinnias, portulaca and small dwarf snapdragons work well in these conditions. For interest add trailers like sweet potato vine or trailing verbena.
For a fragrant planter try spicy scented pinks, dianthus, petunias or nicotiana. Don’t forget that herbs and some vegetables lend themselves to container plantings, too. Basil, parsley, sage, rosemary and thyme grow well in pots. Add some trailing nasturtiums to jazz up the composition.
The latest trend in containers is to combine perennials and annuals together. The best way to get ideas is to visit a garden centre and see what is being offered. Today, more than ever before, there is a wide variety of interesting plant material available. You are limited only by your imagination!