Rosebay Rhododendron Rhododendron 'Fastuosum Flore Pleno' (d)

☠ Toxic to humans
🐾 Toxic to pets
🌸 Blooming
🍪 Not edible
‍🌱 Hard-care
rhododendron 'Fastuosum Flore Pleno'


Rhododendron 'Fastuosum Flore Pleno' is a stunning plant known for its lush, vibrant appearance. It boasts a dense spread of dark green, leathery leaves that provide a year-round backdrop to its most striking feature: the flowers. The blossoms are showy and double, meaning they have multiple layers of petals, which gives them a full, opulent look. These petals range in color from light lavender to violet, with some flowers exhibiting a gradient of hues that can be quite enchanting. Each bloom clusters together with others to form a large, domed-shaped truss that gives the impression of a colorful, floral bouquet nestled among the leaves. The flowers emerge in the spring, offering a display of beauty that easily becomes the focal point of any garden space where it is cultivated. This Rhododendron's overall appearance is one of classic elegance and abundant charm, making it a beloved choice for gardeners looking to add a touch of sophistication to their landscapes.

Plant Info
Common Problems

About this plant

  • memoNames

    • Synonyms

      Lavender Rhododendron, Double Purple Rhododendron, Showy Rhododendron

    • Common names

      Rhododendron 'Fastuosum Flore Pleno'.

  • skullToxicity

    • To humans

      Rhododendron, including the 'Fastuosum Flore Pleno' variety, is toxic to humans. All parts of the plant contain substances known as grayanotoxins. If ingested, even in small amounts, these toxins can cause poisoning. Symptoms of rhododendron poisoning can include burning sensation in the mouth, excessive salivation, vomiting, diarrhea, low blood pressure, and slowed heart rate. In severe cases, ingestion can lead to coma or even be fatal if not treated promptly.

    • To pets

      Rhododendron is toxic to pets as well. Its ingestion can lead to severe and potentially life-threatening symptoms. Symptoms of rhododendron poisoning in pets can include drooling, vomiting, diarrhea, weakness, and central nervous system depression. In extreme cases, cardiovascular collapse, hypotension, coma, and death may occur. It is critical to seek immediate veterinary attention if a pet has consumed any part of a rhododendron plant.

  • infoCharacteristics

    • Life cycle


    • Foliage type


    • Color of leaves


    • Flower color


    • Height

      6 feet (1.8 meters)

    • Spread

      6 feet (1.8 meters)

    • Plant type


    • Hardiness zones


    • Native area



  • money-bagGeneral Benefits

    • Ornamental Value: Rhododendron 'Fastuosum Flore Pleno' has a visually striking presence with its large, double flowers that enhance the aesthetic appeal of gardens and landscapes.
    • Habitat Support: This plant provides habitat and protection for various species of birds and beneficial insects, which take refuge in its dense foliage.
    • Erosion Control: The rhododendron's extensive root system helps stabilize soil, making it useful for controlling erosion on slopes and banks.
    • Seasonal Interest: With its vibrant blooms that appear in the spring, it adds seasonal interest and color to gardens during this time.
    • Privacy Screening: Due to its size and density, it can be used as a natural privacy screen in residential landscapes.
    • Shade Loving: The plant thrives in shaded areas where other plants might struggle, making it ideal for woodland gardens or shaded borders.
    • Durability: Rhododendrons are known for their hardiness and resistance to cold temperatures, making them suitable for a variety of climates.
    • Pollinator Attraction: While it primarily serves as an ornamental plant, it can also attract pollinators like bees and butterflies, contributing to the health of the local ecosystem.
    • Cultural Significance: Rhododendrons are often associated with certain cultures and can be utilized in traditional gardening styles, such as Japanese or English gardens.

  • medicalMedical Properties

    This plant is not used for medical purposes.

  • windAir-purifying Qualities

    This plant is not specifically known for air purifying qualities.

  • leavesOther Uses

    • Rhododendron can be used in bonsai. Due to its attractive flowers and dense foliage, 'Fastuosum Flore Pleno' can be trained into a miniature bonsai specimen.
    • The large, showy blossoms of rhododendrons can be used as a natural dye. The flowers have pigments that can dye fabrics a range of colors, from pinks to purples.
    • The thick foliage provides excellent shelter and breeding grounds for local wildlife, including birds and beneficial insects.
    • In crafts, the dried flowers of rhododendrons can be incorporated into potpourri mixes, adding fragrance and color.
    • Large rhododendron specimens can act as privacy screens due to their dense growing habit, effectively blocking views and reducing noise pollution.
    • These plants are sometimes used in landscape design to create a backdrop for other plants, as their lush foliage contrasts nicely with brighter flowers or variegated leaves.
    • Rhododendron wood is hard and dense, which makes it suitable for carving into small wooden objects such as jewelry or decorative items.
    • The flowers are sometimes used in floral arrangements, especially during the blooming season, to create attractive displays.
    • In some cultures, rhododendron flowers are used in religious ceremonies and decorations as symbols of purity and tranquility.
    • Fallen rhododendron petals can be gathered and added to compost heaps, where they contribute to the nutrient content of the resulting compost.

Interesting Facts

  • bedFeng Shui

    The Rhododendron is not used in Feng Shui practice.

  • aquariusZodiac Sign Compitability

    The Rhododendron is not used in astrology practice.

  • spiralPlant Symbolism

    • Beware: Rhododendrons are often associated with caution or danger, possibly due to the toxicity of their leaves and nectar to humans and animals.
    • Warning: Similarly, they can symbolize a warning to be heeded, as ingesting certain parts of the plant can be harmful.
    • Elegance and Wealth: With their lush, full blooms and often grand presence in gardens, Rhododendrons can represent sophistication and abundance.
    • Survival: These plants are hardy and can thrive in various challenging conditions, symbolizing the ability to overcome obstacles.
    • Passion: Some interpret the vivid colors of Rhododendron flowers as a symbol of intense emotions or passionate feelings.

Every 1-2 weeks
2500 - 10000 Lux
Every 2-3 years
Spring-Early Summer
As needed
  • water dropWater

    Rhododendrons, including 'Fastuosum Flore Pleno', prefer consistent moisture without being waterlogged. Water them deeply once a week, providing about 1 gallon of water per plant during the growing season in the absence of rainfall. Cut back on watering as the weather cools and the plant goes dormant, reducing frequency to once every 2 to 3 weeks. Always check the soil moisture before watering and adjust accordingly; the top inch of soil should be slightly dry to the touch between waterings. Overwatering can cause root rot, so ensuring proper drainage is key.

  • sunLight

    Rhododendrons, such as 'Fastuosum Flore Pleno', thrive best in dappled shade or filtered light. The ideal spot is under the canopy of tall trees that provide light shade, particularly protection from the harsh afternoon sun. They can tolerate morning sun, but too much direct sunlight can lead to leaf scorch. Make sure the location is shielded from strong winds which can desiccate the foliage.

  • thermometerTemperature

    'Fastuosum Flore Pleno' Rhododendrons do best in temperate climates with cool to moderate temperatures, ideally between 50°F and 70°F. They can survive temperatures down to about 20°F but may suffer from cold damage if exposed to prolonged freezing temperatures. These plants usually struggle in areas where temperatures regularly exceed 80°F, especially if nights remain warm.

  • scissorsPruning

    Pruning 'Fastuosum Flore Pleno' Rhododendrons is typically done for shaping or to remove dead or diseased wood. Pruning should occur just after blooming has finished to avoid cutting off next year's buds. Generally, this means pruning in late spring or early summer. Regular trimming to maintain shape isn't necessary; prune only when needed to enhance airflow or to remove unhealthy parts of the plant.

  • broomCleaning

    As needed

  • bambooSoil

    The best soil mix for the Rosebay Rhododendron is well-draining, high organic content soil with a pH between 4.5 and 6.0. A recommended mix is equal parts peat moss, pine bark fines, and perlite or coarse sand. This acidic mixture mimics their native woodland conditions and provides good drainage to prevent root rot.

  • plantRepotting

    Rosebay Rhododendron should be repotted every 2 to 3 years. It’s best to repot in late winter or early spring, just before the growth season begins. Ensure to maintain soil acidity and use a well-draining soil mix at each repotting.

  • water dropsHumidity & Misting

    Rosebay Rhododendron prefers moderate to high humidity levels, typically around 50-60%. They thrive in environments that can mimic the moist, misty conditions of their native habitats. Avoid placing them in excessively dry environments.

  • pinSuitable locations

    • Indoor

      Place in filtered light, ensure high humidity and acidic soil.

    • Outdoor

      Plant in dappled shade, use acidic, well-draining soil.

    • Hardiness zone

      5-8 USDA

  • circleLife cycle

    Rhododendron 'Fastuosum Flore Pleno', commonly known as the Double-Flowered Rhododendron, begins its life cycle as a seed, which germinates in a moist, well-drained, acidic soil environment. The seedling emerges and gradually matures into a woody shrub over several years, developing a robust root system and evergreen foliage. As it becomes established, it enters a cycle of annual growth, producing lush leaves and, in the spring, clusters of vibrant, double flowers. Following pollination, which may be facilitated by insects, the plant produces seed capsules that, upon maturity, release seeds to propagate the next generation. Each year, the shrub enters a dormancy period during the colder months, conserving energy for the next growth season. Throughout its lifespan, which can extend for many years with proper care, the Rhododendron 'Fastuosum Flore Pleno' requires maintenance such as pruning, to manage shape and promote healthy flowering.

  • sproutPropogation

    • Propogation time

      Spring-Early Summer

    • Propogation: Rhododendron 'Fastuosum Flore Pleno', commonly known as the Double-Flowered Rhododendron, is best propagated by semi-hardwood cuttings. This type of cutting is taken in late summer, after the new growth has begun to mature but still retains some flexibility. The cutting should be about 4 to 6 inches (10 to 15 centimeters) long and include several sets of leaves. It's important to use a sharp, clean tool to make the cut just below a leaf node, as this is where roots will develop. The lower leaves are then removed, and the cut end is dipped in a rooting hormone to encourage root growth. The treated cutting is planted in a mixture of peat and perlite, kept moist, and covered with a plastic bag or placed in a propagation chamber to maintain high humidity until roots develop, which usually takes several weeks. Once rooted, the new plants are hardened off gradually before being transplanted to their final location.