Lithodora Lithodora zahnii
ABOUT
Lithodora zahnii, commonly known as Lithodora, presents itself as a striking perennial bearing vibrant blooms and dense green foliage. The leaves of this plant are typically narrow and pointed, resembling small, elongated ovals with a somewhat leather-like texture. They grow densely along the stems, creating lush, green mounds that serve as a verdant backdrop for the flowers. The blossoms of Lithodora are its most captivating feature, usually appearing as brilliant blue or deep purple funnel-shaped flowers. Each blossom has five rounded lobes that flare outward, presenting a star-like shape. The center of the bloom often includes subtle white or yellow patterns, which contrast strikingly with the rich blues and purples, enhancing the plant's visual appeal. As a low-growing perennial, Lithodora spreads predominantly across the ground, forming mats which can cover the soil comprehensively. It is favored for its ability to create a tapestry of color and texture, often used in rock gardens, as a ground cover or along the borders of garden pathways where its showy flowers can be displayed to full effect. The plant generally enjoys sunlit environments where it can bask in the light while showcasing its vivid flowers against the dense foliage, providing a burst of color in garden settings.
About this plant
NamesFamily
Boraginaceae
Synonyms
Purple Gromwell, Zahn's Lithodora
Common names
Lithodora zahnii.
ToxicityTo humans
Lithodora zahnii, commonly known as Lithodora, does not have a well-documented history of toxicity to humans. However, since comprehensive information about its potential toxicity is limited, it is prudent to exercise caution and avoid ingesting any part of the plant. If a plant is not well-studied, it is always wise to consider it potentially harmful and keep it out of reach of children who might accidentally ingest it.
To pets
Regarding Lithodora zahnii, there is limited information available on its toxicity to pets. As with its effects on humans, Lithodora is not commonly known to be poisonous to animals. Nevertheless, since the full extent of its toxicity has not been well-documented, it is advisable to prevent pets from ingesting the plant. If a pet does consume any part of the Lithodora, it is best to monitor for any signs of adverse reaction and consult a veterinarian if any concerning symptoms arise. Symptoms could potentially include gastrointestinal upset, such as vomiting or diarrhea, but specific symptoms of Lithodora poisoning in pets are not well-established due to the lack of detailed research on the plant's toxicity.
CharacteristicsLife cycle
Perennials
Foliage type
Evergreen
Color of leaves
Green
Flower color
Blue
Height
0.5 feet (15 cm)
Spread
2 feet (60 cm)
Plant type
Shrub
Hardiness zones
7
Native area
Mediterranean
Benefits
General Benefits- Ornamental value - Lithodora 'Grace Ward', also known as Lithodora zahnii, adds visual interest to gardens with its vibrant blue flowers and evergreen foliage.
- Drought resistance - Once established, it requires minimal watering, making it suitable for water-wise landscapes and reducing the need for irrigation.
- Ground cover - Its low-growing, spreading habit makes it excellent for covering bare spots, reducing soil erosion, and suppressing weeds.
- Attracts pollinators - The flowers attract bees, which are vital for pollinating plants and supporting healthy ecosystems.
- Low maintenance - Requires little care once established, making it ideal for gardeners who have limited time for upkeep.
- Adaptable to various soils - Can thrive in different soil types, although it prefers well-drained, sandy or gravelly soils.
- Rock gardens and borders - Perfect for use in rock gardens, alpine beds, or as edging due to its compact size and decorative appearance.
- Container gardening - Its small size and low requirement for soil depth make it suitable for planting in pots or other container arrangements.
Medical PropertiesThis plant is not used for medical purposes.
Air-purifying QualitiesThis plant is not specifically known for air purifying qualities.
Other Uses- Lithodora zahnii, commonly known as Zahn's Lithodora, can be used as ground cover due to its mat-forming habit, effectively preventing soil erosion on slopes and banks.
- Its vibrant blue flowers are excellent for creating contrasting effects in rock gardens, pairing well with plants that have yellow or white blooms.
- Zahn's Lithodora is ideal for container gardening, adding a splash of color to patios, balconies, and outdoor sitting areas.
- The plant is beneficial for attracting pollinators, such as bees and butterflies, thus enhancing the biodiversity of a garden.
- Its evergreen nature makes it a valuable plant for winter gardens, providing green foliage throughout the year.
- Due to its compact size and ornamental appeal, Zahn's Lithodora can be used in fairy gardens to create miniature landscapes.
- The plant can be incorporated into seaside gardens because it tolerates salt spray, contributing to coastal landscaping.
- Zahn's Lithodora is also suitable for xeriscaping or water-wise gardening, given its drought resistance once established.
- The plant's ability to adapt to rocky and poor soil conditions makes it an excellent candidate for revitalizing and beautifying challenging garden spots.
- Dried Lithodora zahnii flowers can be used as a natural confetti for outdoor celebrations, offering an environmentally-friendly alternative to synthetic versions.
Interesting Facts
Feng ShuiThe plant Lithodora is not used in Feng Shui practice.
Zodiac Sign CompitabilityThe plant Lithodora is not used in astrology practice.
Plant Symbolism- Resilience - Lithodora zahnii, often known as Purple gromwell, is a hardy plant that thrives in rocky, challenging environments, symbolizing the ability to endure and thrive in difficult circumstances.
- Persistence - The persistence of the Purple gromwell's bloom, which can last throughout the growing season, represents a steadfastness and determination in the face of long-term challenges.
- Adaptation - As a plant that can adapt to poor soils, the Purple gromwell symbolizes the ability to survive and adapt to less than ideal conditions.
- Beauty in Simplicity - With its unassuming but beautiful flowers, the Purple gromwell represents finding beauty in simplicity and appreciating the understated.
WaterPurple gromwell should be watered thoroughly, allowing the soil to become moderately dry between waterings. During active growth in the spring and summer, watering might be required once a week, using about 1 gallon of water for a medium-sized plant. Reduce the frequency to once every two to three weeks in the cooler months and check the top inch of the soil for dryness as an indicator. Overwatering can lead to root rot, so ensure proper drainage. It is critical to avoid letting the plant sit in waterlogged soil, especially during winter.
LightPurple gromwell thrives in a location with full sun to partial shade. It prefers to receive at least six hours of direct sunlight daily, but it can also tolerate some light dappled shade, especially in hot climates. Avoid deep shade areas, as this can result in leggy growth and reduced flowering.
TemperaturePurple gromwell is hardy and can tolerate a range of temperatures but prefers a moderate climate. It can generally survive in temperatures as low as 20°F and as high as 85°F, although it flourishes ideally at temperatures between 60°F and 75°F. Protecting the plant from extreme cold and frost is necessary to prevent damage.
PruningPurple gromwell benefits from pruning to maintain its shape and encourage denser growth. Prune lightly after the blooming period, typically in late spring or early summer, to remove spent flowers and any leggy stems. Every few years, a more substantial pruning may be necessary to rejuvenate older plants. Pruning should be done with clean, sharp tools to minimize damage to the plant.
CleaningNot needed
SoilFor best growth, Lithodora, commonly known as purple gromwell, requires well-drained, sandy or gravelly soil with a slightly acidic to neutral pH between 5.5 to 7.0. A suitable soil mix can be created by combining equal parts of coarse sand, peat, and loamy garden soil to ensure good drainage and aeration. It's important to avoid heavy, clay-rich soils, as they can lead to waterlogging, which can be detrimental to the plant's health.
RepottingPurple gromwell typically does not need frequent repotting as it can thrive in the same container for several years. It should be repotted only when it has outgrown its current pot, which is generally every two to three years. When repotting, choose a slightly larger container to give the roots ample room to grow and refresh the soil mix to provide renewed nutrients.
Humidity & MistingPurple gromwell prefers moderate humidity levels but can tolerate a wide range, from somewhat dry to fairly humid environments. It does not have specific humidity requirements, making it suitable for average household conditions. Ensure there is adequate airflow around the plant to prevent any fungal issues that might arise from high humidity.
Suitable locationsIndoor
Place purple gromwell in bright light away from drafts.
Outdoor
Plant purple gromwell in well-drained soil with partial to full sun.
Hardiness zone
6-8 USDA
Life cycleLithodora zahnii, commonly known as Zahn's Lithodora, typically begins its life cycle with seed germination, which requires a period of stratification to break seed dormancy. Upon germination, seedlings emerge and establish a root system, developing into juvenile plants with vegetative growth observed as foliage expands and matures. This evergreen perennial then reaches the flowering stage, producing characteristic blue flowers that attract pollinators for sexual reproduction. After pollination and fertilization, the plant develops fruit in the form of capsules containing seeds, which are dispersed, completing the reproductive cycle. As an adult, Zahn's Lithodora continues to grow vegetatively and produce flowers annually, typically thriving in well-drained soils with full to partial sun. The plant can persist for several years with adequate environmental conditions, with the life span determined by factors like climate, soil quality, and care practices.
PropogationPropogation time
Spring to Summer
Propogation: Lithodora Diffusa, often known for its striking blue flowers, can be propagated most successfully through softwood cuttings in the late spring or early summer. To do this, a gardener should select a healthy, non-flowering shoot and cut a 4-6 inch (10-15 cm) length. The lower leaves are removed, and the cut end is sometimes dipped in a rooting hormone to encourage root development. The cutting is then planted in a well-draining soil mix, and kept under high humidity by covering with a plastic bag or placing in a propagator. It's critical to keep the cutting in a warm, bright location out of direct sunlight until it has rooted, which can take several weeks. Once the cuttings have rooted, they can be transplanted into individual pots to grow on before being planted out into the garden.
