Growing Rabbiteye Blueberries in Containers
I recently purchased 2 rabbiteye blueberry plants from Lowe's and have transplanted them from the 3.5G planter they came in to a 8G planter (19.2" diameter). I used a traditional potting soil that I treated with 1 cup household vinegar and 2 cups of "Soil Acidifier" containing gypsum and other sulphurs. This has brought my soil pH under 5.0. This concludes what I know about the plants. Can you recommend resources for the car of these plants? I am aware they can grow to be quite large, but I am under the (hopefully realistic) impression that they can be trimmed and pruned to be kept around 5 ft tall. Thank you Nicholas
We generally grow highbush blueberries in Kentucky as opposed to Rabbiteye blueberries because they are hardier and bloom a little later in the spring which helps to avoid flower kill from frost. Rabbiteye blueberries require two different varieties to cross pollinate and set fruit. As your plants get larger and you re-pot the plants into a slightly larger container it would be good to re-pot using pine bark fines. These are acidic and will hold up much longer than peat which will enhance pot drainage and reduce the chances of phytophthora root rot. The pot size will limit the size of the plant growth so it won't get to 10' tall and annual pruning will help keep the plant smaller.
Fertilize with 2 oz of Osmocote 15-9-12 + minors 3-4 month release fertilizer alternated with 3 oz of ammonium sulfate per pot on a monthly basis beginning in March with the Osmocote for a total of 5 applications. The larger garden supply stores carry Osmocote in 1 lb containers. The ammonium sulfate will help to continue to lower the soil pH and the Osmocote will provide iron to the plants which have a problem picking up iron at higher soil pH's. Our city water in Lexington has a pH of about 7.5 and this will continue to raise the pH as the plant is watered. Blueberry plant roots are injured when they reach a temperature of around 18 F, so the roots in potted plants need to be protected by burying the pot in the garden over the winter, mulching heavily around the pot with a medium like sawdust or moving the pot into the coldest part of the garage over the winter once the outside temperature reaches about 15 F. These publications should help out with basic production practices. http://www2.ca.uky.edu/agcomm/pubs/ho/ho60/HO60.PDF https://extension.umd.edu/hgic/topics/planting-blueberries-containers