Daniel Gill, Bogren, Richard C. | 7/28/2008 8:17:29 PM
By Dan Gill
LSU AgCenter Horticulturist
Growing plants outdoors in containers is popular for a variety of reasons. In-ground beds are not always available where you would like to grow plants – as in the case of paved courtyards, decks, apartment balconies and patios. Flexibility and change are two other outstanding container features because landscapes may be altered quickly by changing their arrangement or location of containers.
Nearly any plant may be grown in a container as long as you provide the cultural requirements that the plant needs. You can choose from small-growing evergreen or deciduous trees, shrubs, ground covers, herbaceous perennials and annuals. Tender tropicals may also be good candidates because they can be brought into protected locations during the winter.
The amount of light they will receive is an important factor in deciding which plants would be suitable in a particular location. Whether the location is sunny or shady, you must choose plants that will thrive in those conditions. Also, consider the size of the area and choose containers and plants that will be in proper scale.
You can use a large variety of manufactured containers and found objects varying in size, material, color, shape and design for planting. Only your imagination and taste set the limits, but in most instances, use those with muted colors and simple designs because brightly colored and heavily decorated pots will detract from the plants. Choose larger-sized containers whenever possible, because small containers are usually out of scale with outdoor landscapes and require more frequent watering.
Make sure the containers you use have one or more drainage holes in the bottom to allow excess water to drain out of the pot when you water. This is critically important.
More than anything else, the potting medium used in a container needs to drain well yet retain sufficient moisture to promote good growth. Two basic categories of potting media are suitable – soil mixes and soilless mixes.
Soil mixes contain soil along with organic matter and sharp sand, perlite or vermiculite to improve drainage. Make sure you purchase soil mixes specifically labeled “potting soil” for use in containers.
Soilless mixes have no soil in them and are composed of peat moss, perlite and vermiculite in varying proportions. Their advantages include excellent drainage, good water retention, light weight and freedom from many insect, disease and weed problems. The main drawback is that they are relatively low in nutrients, a problem easily corrected by using slow-release or soluble fertilizers.
Plants growing in containers are far more dependent on you than plants growing in the ground for adequate water. Water whenever the potting medium begins to feel dry when you stick your finger into it but before plants wilt. Watering frequency will vary depending on the type of plant, time of year, temperature and size of the plant in relation to the size of the container.
When you water, water generously until water runs out of the drainage holes. To facilitate watering, the soil should not be level with the rim of the pot. A soil level lower than the pot rim provides a space to hold water while it penetrates down into the medium.
A constant supply of nutrients should be available when the plants are actively growing.
The best choices for fertilizing container plants are either soluble fertilizers or slow release fertilizers because they are less likely to burn plants when used properly. Soluble fertilizers are easy to apply, especially when you use a hose-end applicator, but they must be applied every two weeks to maintain a constant supply of nutrients. Slow-release fertilizers provide nutrients over many months from one application, cutting down on labor.
Container plantings enrich our landscapes in wonderful and unique ways. With proper selection and care, they can provide year-round beauty to liven up a variety of landscaping situations.
Contact: Dan Gill at (225) 578-2222 or firstname.lastname@example.org
Editor: Rick Bogren at (225) 578-2263 or email@example.com