Rhododendron flowers bloom on shrubs in a variety of blossom colors during the spring season. Widely planted for their aesthetic impact, rhododendrons prefer temperate climates with high humidity. Employ appropriate care and pay attention to environmental conditions that may harm your rhododendrons. Look for vigorous plants that can resist problems like chlorosis.
Rhododendron flowers (Rhododendron spp.) bloom from early in the spring season to the middle of the summer season in a wide array of colors including yellow cream, white, salmon, apricot, pink tints, reds, lavender, blue and purple. Shape and size of flowers depends on the particular variety, but blossoms may reach up to 12 inches wide; from summer through autumn, rhododendrons also display dark green foliage until leaf drop. Rhododendron height spans from 5 to 20 feet depending upon cultivar, according to Clemson University Extension.
Rhododendron flowers need dappled shade; excessive exposure to sunlight may result in leaf scorch and diminished health. Plant these flowering shrubs in well-drained soil with an acid pH level of 4.5 to 6.0. If your soil conditions are not ideal, consider the addition of organic matter for more appropriate drainage and nutrient absorption. Since rhododendrons are spring-flowering, plant them during the autumn season for substantial growth time.
Pruning and Mulching
Though rhododendrons may grow successfully without pruning and mulching, the benefits outweigh the drawbacks of the extra work. With pruning, watch for plants with unneeded growth or dead/injured plant parts and apply a light pruning during any time of the year. Always deadhead, or remove stems, as soon as blossoms have completed their flowering cycle for successful blooming during the next season. Mulching is also a beneficial process for rhododendrons because it retains moisture and nutrients that are easily depleted, particularly in sunny environments. Add a thin layer of mulch surrounding your rhododendron plant during the autumn season; use compost when possible as it provides extra nutritional content.
Varieties of rhododendron flowers abound in different shapes and colors. Choose based on the needs of your garden. Carolina rhododendron (R. carolinianum) is a rhododendron with evergreen foliage with flowers in white or pink; this plant reaches a height of 6 feet. The hybrid 'English Roseum' is an upright variety displaying lavender-pink blossoms, reaching a total plant height of 6 feet. Rosebay rhododendron (R. maximum), also referred to as great laurel, displays white to pink flowers and grows to a height of 12 feet, according to Clemson University Extension.
Problems of the rhododendron flower include environmentally induced issues as well as problems of disease and pests. Leaves become scorched from too much wind or sun exposure, so choose your planting space carefully. Iron chlorosis occurs in alkaline soil, causing yellowing of leaves; make sure soil is acid and apply an iron sulfate solution to leaves at 1 oz. per 1 gallon of water to replenish iron and save your plant, as directed by the Virginia Cooperative Extension. Rhododendron flowers generally remain free of pests but borers or mites may appear. Watch for symptoms like stunted plant growth or the appearance of pests on leaf surfaces and determine the appropriate method of insecticidal application for control. Prevalent diseases include dieback and root rot; watch for twig death or decaying of roots and consider fungicidal control. Keeping your plants vigorous through proper care greatly increases their ability to remain pest- and disease-free.