Care of Plants Growing in Containers

Growing plants in containers has rapidly increased in popularity in the last 15 to 20 years.  There are a number of reasons for growing annuals and vegetables in containers.  Container gardens are an excellent way to grow vegetables when suitable garden sites are unavailable.  Container gardening allows individuals to beautify patios, porches, balconies, the front steps, and other areas around the home.  Container gardens also provide individuals with physical limitations an opportunity to grow flowers and vegetables. 
Container gardening is relatively easy.  The basic requirements are suitable containers and a high quality potting mix.  Gardeners also need to meet the basic needs of the plants in regards to watering and fertilizing. 
The frequency of watering may vary considerably from container to container.  Watering frequency depends on the size and type of container, composition of the potting mix, plant species, and weather conditions. 
Plants growing in containers should be checked daily (especially in summer) to determine if they need to be watered.  If uncertain about the need to water, poke your finger into the potting mix.  Water the container when the potting mix is dry at the 1 to 2-inch depth.  Watering frequency may vary from once or twice a day (small container, hot windy weather) to once or twice a week (large container, cool weather).  When watering plants in containers, continue to apply water until water begins to flow out the drainage holes in the bottom of the container. 
Do not allow the potting mix to dry out completely.  Potting mixes shrink and pull away from the sides of the containers when completely dry.  Dry potting mixes are difficult to moisten as water tends to flow between the potting mix and container and then out the bottom of the container (while the potting mix remains dry).  Containers that have been allowed to dry out completely should be placed in a tub of water for 20 to 30 minutes to remoisten the potting mix. 
Plants in containers need to be fertilized on a regular basis as nutrient levels in potting mixes quickly fall due to absorption by plants and leaching during watering. 
Many commercial potting mixes contain a slow release fertilizer.  However, slow release fertilizers usually don't last the entire growing season.  When using a potting mix containing a slow release fertilizer, begin to fertilize plants when plant growth slows or the color of the foliage fades.  A granular fertilizer can be applied to the soil surface or plants may be fertilized with a water soluble fertilizer.  Check the product label for application rates and frequency. 
Other Maintenance Chores
Remove spent flowers on annuals to improve plant appearance and encourage continuous bloom.  Pinch back plants that get tall and leggy. 
Harvest vegetables at the proper stage of maturity for best quality and to encourage additional production. 
Inspect plants on a regular basis for insects and diseases.  Control insects by either handpicking or by spraying/dusting with the appropriate insecticide.  Control diseases by removing infected leaves or entire plants.


Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on July 1, 2016. The information contained within may not be the most current and accurate depending on when it is accessed.