The name “geranium” often causes confusion, as it refers to two genera in the Geraniaceae family. True geraniums belong to the genus Geranium, known as cranesbills, which are typically hardy perennials. However, the plant cultivated for its fragrant essential oil and medicinal properties is the scented geranium, belonging to the genus Pelargonium (e.g., Pelargonium graveolens). This South African native is prized for its aromatic leaves and flowers, yielding the oil widely utilized in aromatherapy and cosmetics. This article focuses on the versatile applications of the scented Pelargonium, the source of the popular “geranium” oil.
Therapeutic Properties of Geranium Essential Oil
The essential oil derived from Pelargonium species is characterized by a high concentration of monoterpenoid compounds, primarily citronellol and geraniol. These compounds contribute significantly to the oil’s biological activity. Depending on the specific variety, citronellol can be present at levels around 30% and geraniol around 13–15%.
These compounds provide the oil with recognized antimicrobial and antifungal properties, effective against various bacteria and fungal strains, including Candida species. This action stems from the ability of geraniol and citronellol to disrupt the metabolic functions of microorganisms. Geranium oil also exhibits anti-inflammatory effects, observed through its ability to inhibit nitric oxide production.
In skincare, the oil is used for its astringent and balancing qualities, helping to regulate sebum production. Its regenerative properties promote cell turnover and speed the healing of minor wounds and irritations. The oil is also rich in antioxidant compounds, such as flavonoids, which neutralize free radicals.
Beyond topical uses, the oil plays a significant role in aromatherapy, where its rose-like scent is utilized for emotional support. Aromatic compounds interact with the olfactory system to produce a calming effect. This has led to its traditional use in managing stress, anxiety, and fatigue, contributing to emotional balance.
Horticultural and Pest Deterrence Applications
The Pelargonium plant holds significant value in horticulture due to its aesthetic appeal and hardiness. These plants are popular for use in window boxes, container gardens, and mass plantings, offering vibrant colors that bloom from spring through fall. Their thick, fleshy leaves and stout stems make them robust ornamental plants that tolerate warm, sunny conditions with well-drained soil.
The plant’s strong, characteristic scent is the basis for its application in pest deterrence. Scented Pelargoniums naturally produce volatile compounds that are off-putting to certain insects. The presence of a live plant is often cited for its ability to deter mosquitoes by continuously releasing its aromatic profile.
Studies show that the essential oil, especially varieties rich in citronellol and geraniol, functions as an effective biting deterrent against species like the Aedes aegypti mosquito. In the garden, the plant’s foliage is unpalatable to common pests like slugs and snails. While not immune to all garden pests, its presence contributes to a natural pest management strategy.
Guidelines for Safe Use and Application
Geranium essential oil requires careful handling and proper dilution before topical application. Applying undiluted oil directly to the skin can cause irritation, sensitization, or allergic contact dermatitis. For most adults, a typical topical dilution ranges between 2% and 5%, meaning a few drops are mixed into a carrier oil such as jojoba or coconut oil.
Before using a new blend, a patch test is recommended to check for adverse reactions. This involves applying a small amount of the diluted oil to an inconspicuous area, like the inner forearm, and observing the site for 24 to 48 hours for signs of redness or itching. If irritation occurs, the area should be washed gently, and use of the oil discontinued.
Inhalation through diffusion is generally considered a safer method, though it requires good ventilation to avoid prolonged exposure. Essential oils should not be ingested unless under the direct guidance of a qualified health professional. Since the beneficial oil comes specifically from the Pelargonium species, confirm the correct botanical name to ensure safety and efficacy.