Several planting techniques can be used advantageously to enhance the appearance of container plants.
Container gardeners can achieve a more finished appearance by using larger plants or by combining several large plants in a single container. For example, a 6 to 7-inch potted geranium already in bloom could be started in a 3- gallon container. Several 6- to 7-inch potted caladiums might be used initially in a half barrel. Or a 2-gallon potted hibiscus already in bloom could be transplanted in early spring in early spring or early summer to a 5- to 7-gallon container. This gives an immediate colour effect.
Another approach might be to use 4-inch potted annual flowers initially. Several 4-inch plants already in bloom can be re-potted into a larger container. Three or four plants are sufficient for an 18- to 26- litre container. Some colour is obtained immediately; however, after several weeks of growth, the colourful effect is more dynamic.
Small and more economical flowering plants also can be used at first. You will need about a half dozen plants for an 18 to 26 litre container. Plant these close to the edge of the pot with one plant in the middle. This procedure allows ample room for growth and air circulation. From four to six weeks of growth will be required to obtain a good effect.
When filling containers, do not pack the soil, simply bump the container in the ground lightly to settle the soil. Fill the container to within 2 inches of the top of the container. This will leave sufficient room for water to thoroughly soak the soil. Before knocking out and planting individual plants, thoroughly wet the root mass.
Plant individual plants so roots are set shallowly rather than deeply and gently firm soil around the roots. Finally, water the plants in thoroughly. This may require a couple of waterings in succession to wet the mixture entirely.
Proper watering is essential for a successful container garden and one watering per day is usually adequate. However, poor drainage will slowly kill the plants. If the mix becomes water-logged, the plants will die from lack of oxygen. Avoid wetting the foliage of plants since wet leaves will encourage plant diseases. Remember to use the nutrient solution for each watering except for the weekly leaching when you will use tap water.
Water-holding gels are becoming popular for use in container gardening. These starch based gels are called hydrogels. They absorb at least 100 times their weight in water and slowly release that water into the soil as it dries. To be effective, they should be incorporated in the soil mix before planting.
Cultivating the soil at a depth of 2 to 3 inches below the surface of the potting medium will encourage maximum air flow around the roots, which encourages bigger and healthier root growth and subsequently better water and nutrient uptake.
Weeding allows the plants to benefit from the nutrients and water that is provided by the medium without having to compete with other non-productive plants. It has to be considered that weeds being native to the environment, usually grow bigger and faster, than cultivated crops.
A gardener does not need to fertilize container plants the first two to three weeks after planning if the potting mixture was amended with fertilizer. Nutritional levels usually drop after this period because plants use them and because nutrients are leached from the soil because of frequent watering.
Fertilization of annuals and perennials of a succulent or soft nature should start about two to three weeks after potting. The frequency of fertilization depends on the method you use. For example, if you use a so-called liquid soluble fertilizer, make an application every two to three weeks during the growing season. If more rapid growth is desired, fertilize every one to two weeks.
Mix soluble fertilizer according to the label directions and apply as a normal watering. Apply enough of the solution so some drains out of the bottom of the container. If a dry, garden type fertilizer is used, it should be applied every three to four weeks. One-half teaspoonful of fertilizer per gallon of soil mixture spread evenly on the soil surface is adequate. Watering after applying the fertilizer dissolves the nutrients and carries them into the root zone. Watering the fertilizer in reduces chances of fertilizer damage to stems and roots.
Slow release fertilizers are popular. These are sold in the form of small, round pills. They release fertilizer gradually when wet. The type that lasts approximately three months is generally used. A teaspoonful per gallon of soil is usually recommended. Check the recommendations on the container because products differ and rates vary.
Fertilize containerized trees and shrubs of a woody nature as often as succulent plants. Woody plants should do nicely if fertilized in early rainy season (March) and again in May and July. Granular type, garden fertilizers at the rate of ½ teaspoonful per gallon of soil mix per application will be adequate. Slow release fertilizers that last six to nine months have proven satisfactory for shrubs and trees in containers. Apply them in early spring. Spread the pellets evenly on the soil surface at the rate of 1 teaspoonful of the material per gallon of the soil mixture.