Cardinal flower Lobelia × speciosa 'Sparkling Ruby'

☠ Toxic to humans
🐾 Toxic to pets
🌸 Blooming
🍪 Not edible
‍🌱 Hard-care
Lobelia 'Sparkling Ruby'


Lobelia × speciosa 'Sparkling Ruby' is an ornamental plant that is primarily recognized for its striking flowers and foliage. The flowers are a vibrant ruby-red or deep pink color, and they display a unique two-lipped appearance that is characteristic of the Lobelia genus. The upper lip is typically a duo of small petals while the lower lip has a more prominent and lobed structure, creating a visually appealing contrast. The foliage of 'Sparkling Ruby' complements its radiant blooms, with leaves that are often a rich green color, occasionally exhibiting a bronzy undertone. The leaves are lance-shaped with a somewhat serrated edge, contributing a lush, textural backdrop to the showy flowers. The plant itself forms a clumping habit, which gives rise to numerous flower spikes that bear the tubular blossoms. These spikes emerge above the foliage, giving the plant a layered and dimensional appearance. The overall impression of Lobelia × speciosa 'Sparkling Ruby' is one of vibrant color and lushness, making it a sought-after choice for adding bold accents to gardens and landscapes.

Plant Info
Common Problems

About this plant

  • memoNames

    • Synonyms

      Hybrid Lobelia, Garden Lobelia, Spiked Lobelia.

    • Common names

      Lobelia × speciosa 'Sparkling Ruby'.

  • skullToxicity

    • To humans

      Lobelia is known to contain toxic alkaloids, such as lobeline, which can be potentially harmful if ingested in significant quantities. In humans, symptoms of poisoning from Lobelia may include nausea, vomiting, diarrhea, cough, dizziness, tremors, and rapid heartbeat. In severe cases, it may lead to convulsions, hypotension, coma, and potentially death, especially if consumed in large amounts. It is advisable to avoid ingesting any part of the Lobelia plant.

    • To pets

      Lobelia is also toxic to pets due to the presence of alkaloids such as lobeline. If a pet ingests the plant, they could experience similar symptoms to humans, which might include nausea, vomiting, diarrhea, excessive salivation, and signs of nervous system issues like tremors and convulsions. Ingesting Lobelia can be dangerous for pets and could potentially lead to serious health complications; therefore, pet owners should prevent their animals from consuming any part of the plant.

  • infoCharacteristics

    • Life cycle


    • Foliage type


    • Color of leaves


    • Flower color


    • Height

      2 feet (0.61 meters)

    • Spread

      1 foot (0.30 meters)

    • Plant type


    • Hardiness zones


    • Native area



  • money-bagGeneral Benefits

    • Attracts Pollinators: The vibrant blooms of Lobelia × speciosa 'Sparkling Ruby' attract butterflies and bees, enhancing pollination in the garden.
    • Visual Appeal: With its striking ruby-red flowers, it serves as a colorful focal point or accent in garden beds and borders.
    • Low Maintenance: Once established, it requires minimal care, making it a convenient choice for busy gardeners.
    • Durable: It is relatively resistant to pests and diseases, ensuring a healthy and robust display.
    • Versatile: Suitable for container gardening, borders, and as ground cover, providing flexibility in garden design.
    • Long Blooming Period: It has a lengthy flowering season, offering visual interest throughout the summer and often into fall.
    • Hummingbird Friendly: The tubular flowers are particularly attractive to hummingbirds, offering them a valuable nectar source.

  • 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

    • Lobelia × speciosa 'Sparkling Ruby', commonly known as Lobelia, can be used as a natural dye for fabrics, offering a range of purple and pink hues depending on the mordant used.
    • The plant's stems and flowers, when dried and powdered, can be sprinkled on coal or a fire to create a natural insect repellent due to the smoke.
    • The vibrant flowers can be used in potpourri mixes, adding color and a light, pleasant scent to the mixture.
    • Lobelia is sometimes used in floral art and pressed flower crafts due to its striking color and the durability of its petals.
    • The leaves and flowers can serve as a subtle flavor additive for specialty liqueurs when infused in small quantities.
    • It can be utilized as a living mulch; its dense foliage can suppress weeds and retain soil moisture in garden beds.
    • Due to its intricate flowers, Lobelia can be used in educational settings as an example of plant structure and pollination biology.
    • Garden designers may use Lobelia as a natural indicator plant to signal too-wet conditions when it shows signs of stress in overly moist soils.
    • With its colorful blooms, Lobelia can be incorporated into natural jewelry, such as pressing the flowers into pendants or laminating them into bracelets.
    • As a companion plant in the vegetable garden, Lobelia can attract beneficial insects which in turn help with pollination and pest control.

Interesting Facts

  • bedFeng Shui

    The Cardinal Flower is not used in Feng Shui practice.

  • aquariusZodiac Sign Compitability

    The Cardinal Flower is not used in astrology practice.

  • spiralPlant Symbolism

    • Transformation: The Lobelia, with its vibrant colors, often signifies change or a transition, reflecting the transformation in nature or personal growth in an individual's life.
    • Devotion: The intense hues of the 'Sparkling Ruby' variety can symbolize deep feelings of love and commitment, making it a symbol of steadfast devotion.
    • Communication: Historically associated with expressing thoughts, the Lobelia can represent the need to communicate or express one's feelings clearly.
    • Healing: Known for its medicinal properties, the Lobelia plant is often synonymous with healing and recovery from illness or emotional distress.
    • Protection: Some cultures believe the plant offers protection from negativity or evil spirits, signifying spiritual defense and safeguarding.

Every 1-2 weeks
500 - 2500 Lux
Every 2-3 years
Spring to early summer
As needed
  • water dropWater

    The Cardinal Flower should be watered deeply enough to saturate the root zone, which typically means providing about 1 inch of water weekly. During hot, dry spells, you may need to water twice a week, ensuring the soil remains moist but not soggy. Avoid overhead watering to minimize leaf wetness and reduce the risk of disease. Allow the top inch of soil to dry out before watering again to promote healthy root growth. In terms of quantity, this might translate to about 0.5 gallons for a small to medium-sized plant, depending on the environment and soil type.

  • sunLight

    The Cardinal Flower thrives in partial shade to full sun. It grows best when exposed to bright, indirect light or filtered sunlight for most of the day. However, it will appreciate some shade during the hottest part of the day, especially in warmer climates. An ideal spot would be an area that receives morning sunlight and afternoon shade, or dappled sunlight under a canopy of trees.

  • thermometerTemperature

    Cardinal Flowers prefer temperatures between 60°F and 75°F and are hardy in USDA zones 4 to 9. They can withstand minimum temperatures down to about -30°F and maximum temperatures up to about 90°F, although prolonged exposure to extremes can be detrimental. The plant performs best within this moderate temperature range and should be protected from harsh winter cold with mulch and from extreme summer heat with shade.

  • scissorsPruning

    Pruning the Cardinal Flower involves deadheading spent flowers to encourage new blooms and improve the plant's appearance. Cut back the entire plant in late winter or early spring, before new growth begins, to promote a bushy habit and remove any dead or damaged growth from the previous season. Pruning can be done as needed throughout the growing season to maintain the desired shape and size.

  • broomCleaning

    As needed

  • bambooSoil

    Cardinal Flower 'Sparkling Ruby' thrives in moist, well-draining soil with a rich organic content. A soil mix composed of loam, peat, and compost is ideal, ensuring both moisture retention and good drainage. The soil pH should be slightly acidic to neutral, ranging from 6.0 to 7.0.

  • plantRepotting

    Cardinal Flower 'Sparkling Ruby' generally doesn't require frequent repotting and can be repotted every 2-3 years to refresh the soil. Spring is the best time for repotting to allow the plant to establish before the growing season.

  • water dropsHumidity & Misting

    Cardinal Flower 'Sparkling Ruby' does best in moderate to high humidity levels but is quite adaptable and can tolerate the average humidity found in most homes.

  • pinSuitable locations

    • Indoor

      Provide bright indirect light, consistent moisture, and good air circulation.

    • Outdoor

      Plant in partial shade, keep soil moist, and protect from strong winds.

    • Hardiness zone

      4-9 USDA

  • circleLife cycle

    Lobelia × speciosa 'Sparkling Ruby', commonly known as Sparkling Ruby cardinal flower, begins its life cycle as a seed, requiring stratification or a period of cold to break dormancy. Once germinated, usually in spring, the seedling stage involves developing roots and foliage in a moist environment. As it matures, the plant enters the vegetative stage, growing larger and forming a rosette of leaves at the base. During the flowering stage, typically in late summer to early fall, it produces tall spikes adorned with vibrant, ruby-red flowers that are attractive to hummingbirds and butterflies. After pollination, it sets seed, completing its reproductive cycle. The plant then either dies back in winter if it is an annual or enters a period of dormancy if it is a perennial, preserving energy in its root system for the next growing season.

  • sproutPropogation

    • Propogation time

      Spring to early summer

    • Propogation: Lobelia × speciosa 'Sparkling Ruby' is commonly propagated through division, which is generally the most popular method for this ornamental plant. The best time to propagate by division is in the spring, just as the plant is resuming growth and when there is plenty of time for the new plants to establish before hot weather. To divide 'Sparkling Ruby', carefully lift the plant from the ground with a shovel, ensuring a good amount of roots with each piece. Gently tease apart the clumps of foliage and roots into smaller sections, making sure that each new division has several growing points or shoots. Replant the divisions immediately at the same depth they were growing previously, water thoroughly, providing about a gallon (approximately 3.8 liters) of water per division to help reduce transplant shock and ensure good contact between the roots and the soil.