Preparation And Care Of Potted Plants
The key to growing potted plants successfully lies in understanding the individual requirements of plants growing in an unnatural environment, says a gardening specialist in Penn State's College of Agricultural Sciences.
"Maintaining plants in containers -- no matter what shape, size or type -- presents problems," says Robert Nuss, professor of ornamental horticulture. "But if all the conditions necessary for growth are in balance, the plant will flourish."
Nuss suggests following a few simple practices when purchasing or preparing new potted plants.
Isolation. Before purchasing, check all plants carefully for insects, mites or disease. Regardless of what you find, isolate the plants for at least two weeks. "Any insects or mites can be controlled in the early stages of development with a pesticidal soap solution available at most garden centers," Nuss says. "Larger infestations should be controlled with aerosol sprays."
Soil. The ideal potting soil should drain well and have a light texture. Nuss recommends a high-humus topsoil if you have very large containers -- with a volume of a bushel or more. "Nearly all potting soil will be improved if you mix in about 10 percent coarse material, such as sand or vermiculite," he says.
If homeowners use garden soil in pots and containers, Nuss suggests pasteurizing the soil by moistening the mixture and heating at 180 degrees Fahrenheit for exactly 30 minutes. "Higher temperatures and longer heating times can damage the soil," Nuss warns. "Allow the mix to cool before using it around roots."
Moistness. Nuss says it is critical that a potted plant remain moist once it has been established. Even short dry periods can affect roots and the plant. "When plants become too dry, soluble salts in the soil can reach toxic levels, further injuring the root system," Nuss says.
Fertilization. Nuss recommends fertilizing potted plants lightly and only during active growth, when they need added nutrients. "Don't use a high-nitrogen fertilizer when plants are in bloom," Nuss says.
Leaching. Periodically flush the soil with soft water if available. The leaching action of this watering will eliminate any soluble salts that have built up in the soil, Nuss says. "Leaching is done by adding water in an amount four or five times the soil volume in the container," he adds. "The extra water pushes the mineral salts through the pot's drain hole. Be sure to discard the leaching water coming from the pot."
Light. Research the light requirements of your plants or ask a knowledgeable person at a local garden center or nursery. Nuss says most flowering plants need a large amount of sunlight. "On the other hand, foliage plants that are moved from indoors can be damaged by full sunlight." Nuss says. "Avoid sudden changes in light intensity or temperature because the resulting shock can cause leaf or flower drop."