Red Azalea Shrub Facts

Taxonomy

• Taxonomy is the fancy word for scientific classification. Numerous species of azalea exist, many of which bear red flowers. As such, no single species or type of red flowering azalea exists. Rather, these plants constitute various species of the azalea genus, Rhododendron. Because azaleas belong to the Rhododendron genus, they technically constitute types of rhododendrons. The Rhododendron genus belongs to the dicot class (Magnoliopsida), angiosperm division (Magnoliophyta) and vascular plant subkingdom (Tracheobionta) of the plant kingdom. This means azalea produce vascular tissue and reproduce via seeds.

Garden Azaleas

• Most common types of garden azaleas constitute hybrid varieties or cultivars. Hybrid varieties constitute new types of plants created by combining the genetic material of related species, while cultivars constitute plant types created specifically for growth in controlled environments like gardens. Red flowering azaleas include the "Firestorm" large leaf cultivar, the "Red Red" evergreen azalea cultivar, the dark red "America" hybrid, the "Hinodegiri" Kurume hybrid and the "President Clay" Southern Indica hybrid. When buying red azaleas, ask about a plant’s status as a hybrid or cultivar if this information interests you.

Zone Tolerance

• The zone tolerance of a plant describes the areas of the United States in which that species, hybrid or cultivar grows to optimal results. Generally speaking, azalea grow best in USDA zones 6 through 9, or areas with an average minimum annual temperate range of minus 10 to 30 degrees Fahrenheit. Originally from Asia, azaleas usually prefer temperate or warm areas. However, hybrids experience radically divergent tolerance, some exhibiting cold hardiness and others preferring warm climates. For information on azaleas suited to growth in your area, contact a local greenhouse, garden supply store or university extension.

Azalea Culture

• Plant culture describes the ideal growing environment for a species, hybrid or cultivar. Because azaleas grown in gardens bear close relation to one another, all types of red flowering azalea shrubs possess similar culture requirements. These requirements include shelter from wind, partially shaded areas with filtered sunlight, and well-drained soil. Azaleas prefer soil with a pH range of 4.5 to 5.5 and enhanced by organic material, like mulch or compost. A layer of mulch around the base of an azalea shrub helps the soil surrounding the plant retain moisture; since azaleas produce shallow roots, the plants often require help accessing water. This also means plants need regular watering in dry periods.