Look at hybrid varieties such as the pink flowering yaks (R. yakushimanum) that bears pink and white flowers, or the Rhododendron lutescens for light-yellow blooms and new leaves that start off red. Choose a half-barrel for the tallest or those with wide root systems; consider a 10- or 15-gallon container for others. As such they perform best when the soil is acidic (with a pH between 4.5 and 6.0). Is it a Rhododendron or an Azalea? Scientifically speaking, all azaleas are of the genus Rhododendron. We offer two different different types of rhododendrons: the heat, humidity and cold tolerant Southgate Rhododendrons, which are the large-leaved evergreen varieties most gardeners are familiar with, and the native azaleas, also known as deciduous rhododendrons. Proper soil conditions are very important. Generally large-leaf rhododendrons are less tolerant of sun and wind than small-leaf rhododendrons or evergreen and deciduous azaleas. (See Soil Conditions for more information.) If growing rhododendrons in containers, use an ericaceous compost . With their shallow roots, rhododendrons can grow well in pots. The root ball should be soaked prior to planting. Place the plant in a tub or bucket for a brief soaking, until air bubbles disappear. Moisture is required for proper rhododendron care. Select dwarf varieties of rhododendrons when planting in containers. Rhododendrons don't like having wet feet; in fact, soggy, waterlogged ground is the most common cause of failure. If you have a heavy clay soil, plant your rhododendron in a mound of improved soil as described below. Rhododendrons are acid loving plants. Plant the rhododendron bush so that its crown is at the same level as in the pot.