I enjoyed your article on blueberries last week, but I garden in New Orleans, and you mentioned that the soil here is not acid enough. Would I be successful growing blueberries in containers? And, if so, do you have any advice? — Andy Newson
Given the alkaline soil common on the south shore, it’s good news that research done at the LSU AgCenter’s Hammond Research Station shows that blueberries can be grown successfully in containers. Growing blueberries in containers allows us to provide them with the acid soil conditions they need. The following information is based on that research.
Plant the blueberry bushes individually in 15-gallon containers. Make sure the containers have several drainage holes to allow excess water to drain when you water. Fill the containers with a growing mix made up of one-half peat moss and one-half finely ground pine bark mulch (you may find this in bags labeled “soil conditioner”). It will be necessary to add fertilizer to provide the nutrients needed by the bushes. Per 15-gallon container, add and blend well with the peat-bark mix 8 ounces of Osmocote 17-7-12 or 16-4-8 (or anything similar), 2 ounces of dolomitic lime and 1 ounce of trace elements (Micromax or other trace element fertilizers would be suitable, follow label directions). Each March, fertilize your container blueberry plants with 8 ounces of a slow-release fertilizer such as Osmocote.
The plants in the research study that did best received about six hours of sun with some shade in the afternoon. Locate your container blueberries on the east or southeast side of a house or other structure to provide this type of light. Avoid shady areas. It would be better to provide the plants with more sun than more shade.
Water is important and must be applied regularly, especially in the heat of summer. Larger containers dry out slower than smaller ones, but even a 15-gallon container may need to be watered two or three times a week. The peat-bark mix will dry out faster than regular potting soil, so check it frequently and water as needed.
Blueberry bushes are quite hardy and there is no need to protect the plants during the winter. Moving a 15-gallon container inside during freezes would not be my idea of fun.
After a few years, you can expect to average around 5 to 7 pints of fresh, sweet blueberries per plant each summer. If birds are a problem, cover the plants with bird netting. There are few insect or disease problems you are likely to encounter. Blueberries are remarkably carefree for the fruit they provide.
In about four years, the plants will outgrow the 15-gallon containers, and the vigor and productivity of the bushes will decline. They should be transplanted into 25-gallon containers when that occurs. This is best done between November and February. Place about 5 gallons of finely ground pine bark mulch in the bottom of the container. Next, repot the bush, filling in around it with a blended mix of 75% finely ground pine bark and 25% peat moss to which 4 ounces of Osmocote 17-7-12 (or anything similar), 1 ounce of dolomitic lime and ½ ounce of trace elements has been added.
I have a pecan sapling in my backyard, and every summer it seems something comes and chews up the leaves. Do you have a recommendation of what to do? — Chris Bayer
There are various caterpillars that will feed on pecan leaves. All of them can be controlled organically with regular sprays of the insecticide spinosad (various brands wherever you buy your garden pesticides). Regular sprays through the summer should help minimize any additional damage.
Garden columnist Dan Gill answers readers' questions each week. To send a question, email Gill at dgill@agcenter.lsu.edu.
