(News article for March 26, 2022; edited)
Fruit trees and bushes can be grown in containers on a variety of sunny sites. Besides allowing us to grow fruits even if we don’t have a yard with well-drained soil and sufficient sunlight, container culture gives us the flexibility to grow plants that may need cold protection at some point in the year, if they can be moved into a protected area.
Many types of fruit plants can be grown in containers, though plant size and fruit production will likely be limited in comparison with the same plant grown in favorable conditions in the ground. Plants may eventually outgrow their containers and need to be moved to a larger container, planted in the ground, or replaced.
Citrus trees are commonly grown in containers in Louisiana. Types that naturally stay smaller – like kumquats, satsumas, lemons, and limes – are better suited to container culture than ones that grow larger, like oranges and grapefruits.
Southern highbush blueberries stay smaller than our traditional rabbiteye blueberry plants. They’re also more finicky about soil drainage and pH, and may perform poorly when planted in the ground in less-than-ideal conditions. They can be planted in 10- to 15-gallon containers, with aged pine bark alone as a substrate, instead of a typical potting mix.
Planting Southern highbush blueberry plants in pots can allow us to grow varieties that have low chilling requirements and bloom (and fruit) early. Plants can be brought into a protected area if temperatures get very cold when the plant is in bloom or has ripening fruit on it.
Erect blackberry varieties suited for production in the ground here can be planted in containers. One option is to cut the first-year canes (primocanes) off once they reach about 3 feet tall, though this will limit fruit production the following year. You can also provide support and let them grow taller.
As mentioned above, containers as small as 10 to 15 gallons can be used for some fruits. Halved whiskey barrels or wooden boxes measuring roughly 2 feet in all dimensions, such as those used historically in French orangeries, are also possibilities. If you’ll need to move your plant, consider how large of a container you’ll be able to handle.
Regardless of what type or size of container you use, be sure it has enough holes in the bottom to allow sufficient drainage. Good drainage is imperative in container plantings.
Use a potting mix rather than real topsoil or garden soil. Leave enough space above the substrate and below the rim of the container to allow water to pool briefly before it soaks in.
Place the container in a site with adequate sunlight. “Full sun” is usually defined as at least 6 or 8 hours of direct sunlight per day. As a rule, more direct sunlight results in more production.
Take care to neither let roots get too dry nor overwater them. Plants in wooden or clay containers will generally need to be watered more often than those in plastic or ceramic containers. When you water, do so until water runs out of the holes at the bottom.
Since plants in containers will stay relatively small, fertilizer recommendations for fruit plants in the ground are not directly applicable to potted ones. A couple of options are to use either slow-release fertilizer or one dissolved in water prior to application, beginning in late winter or early spring. Readily soluble fertilizers will need to be applied more often, whereas slow-release fertilizers will provide nutrients over a period of weeks or months. Avoid fertilizing late in the growing season, especially with slow-release fertilizers, since late fertilization can increase plants’ susceptibility to cold damage. For citrus, don’t fertilize after the end of June.
If you plan to move plants into a protected area (such as a sunroom) for a long period in the winter, or if you’re moving them back outside after being inside for a long period, acclimate them gradually.
Let me know if you have questions.
Contact Mary Helen Ferguson.
Kumquats tend to stay smaller than most other citrus trees and are well-suited to being grown in containers. (Photo by M.H. Ferguson)
Southern highbush blueberry plants can be grown in containers filled with aged pine bark. (Photo by M.H. Ferguson)