Whiskey barrel containers for garden use come as either entire barrels minus the lids or as barrels sawn in half. Some may already have drilled holes in the bottom. If not, you must add these because container plants need adequate drainage. Before adding soil to the barrel, line the bottom with broken crocks as a further drainage aid.
Azaleas, which come in deciduous and evergreen varieties, have very specific soil needs. You must plant them in a well-drained acid soil to ensure healthy specimens. This makes them ideal for growing in a whiskey barrel since you can buy special soils for growing azaleas from garden stores. Use only this type of soil in the container. Gardeners grow azaleas for their colourful blooms, which appear from mid-April to mid-May in most varieties, though some bloom later. The Ohio State University Extension recommends fertilising them once a year in spring or fall with a fertiliser specially designed for acid-loving plants. Azaleas like to be damp but not sodden and grow best in a sheltered spot with partial shade.
Camellias produce delicately petalled blooms in a large variety of colours including pink, white and red. The blooms appear from winter through spring on this evergreen plant. Camellias like an acid soil, so buy ericaceous (lime--free) compost to use as a growing medium in a whiskey barrel. This shrub can grow as high as 6 feet, but they are slow growing and a container limits their ultimate size. Container-grown camellias do best in partial shade in a sheltered spot. You can prune camellias in spring, cutting out dead and damaged branches and shaping the plant as you want it to grow. Camellias can reach a great age and the Clemson University Extension points out that some growing around the Imperial Palace in Tokyo are more than 500 years old.
Holly bushes come in many varieties, including around 20 native to North America. Choose one of the smaller growing varieties to grow in a whiskey barrel. Nana, for example, grows to a maximum height of 5 feet and Shillings grows to only 3 feet. The University of Arkansas Cooperative Extension points out that holly is dioecious, meaning the plants are male or female. Only the female holly produces the red berries, and only then if there is a male plant near enough (within 2 miles) for pollination. Hollies come in both evergreen and deciduous varieties and most have dark green shiny leaves although variegated varieties with lighter tones are available.