Pelargonium ‘Citrosum’

Pelargonium ‘Citrosum’: The Mosquito-Repellent Scented Geranium

Pelargonium ‘Citrosum’, or Pelargonium ‘Citronella’ commonly known as the Citronella Plant, Mosquito Plant, or Citrosum Geranium, is a perennial herbaceous plant. It is from the Geraniaceae family. Originating from southern Africa, this plant has been popular for its distinctive lemon-scented foliage and its purported ability to repel mosquitoes. Although its effectiveness as a mosquito repellent has been contested, it remains a popular choice for gardeners seeking a fragrant and ornamental addition to their outdoor spaces.

Botanical Description

Pelargonium ‘Citrosum’ is a subshrub that typically grows upright with a bushy habit. It can reach a height of up to 24 inches (60 cm) and spread up to 18 inches (45 cm) wide. The plant features deeply cut, crinkled, and serrated soft green leaves that emit a sharp citrus scent when bruised. The fragrance is most pronounced when the leaves are touched or crushed, making it a delightful sensory addition to any garden.

During the summer months, the plant produces clusters of small, lavender-pink flowers adorned with deep crimson brush marks on the top petals. These 1-inch (2.5 cm) blooms add a subtle splash of color to the vibrant green foliage. While not as showy as some other flowering plants, the combination of attractive foliage and delicate flowers makes Pelargonium ‘Citrosum’ a versatile choice for various garden settings.

Growing Conditions and Care Instructions for Pelargonium ‘Citrosum’:

Light Requirements: Pelargonium ‘Citrosum’ thrives in full sun, requiring at least 6-8 hours of direct sunlight each day. While it can tolerate some light shade, especially in the heat of the day, full sun exposure is essential for optimal growth and flower production.

Soil Requirements: This plant prefers rich, well-draining soil with a slightly acidic to neutral pH (6.0-7.0). If planting in the ground, amend heavy or clay soils with compost or sand to improve drainage. When grown in containers, choose a pot with drainage holes and use a well-draining potting mix.

Watering: Pelargonium ‘Citrosum’ requires regular watering during the growing season but is drought-tolerant once established. Allow the top inch (2.5 cm) of soil to dry out between watering sessions. Overwatering can lead to root rot, so it’s better to underwater slightly than to keep the soil too moist. During winter, reduce watering to allow the plant to rest.

Fertilization: To encourage vigorous growth and abundant flowering, feed the plant with a balanced, water-soluble fertilizer every 4-6 weeks during the growing season. Apply a slow-release granular fertilizer in spring to provide nutrients throughout the season.

Pruning: Regular pruning is essential for maintaining the plant’s shape and encouraging bushier growth. Pinch back the stems and remove spent flowers to promote fresh growth. Pruning also helps prevent legginess, keeping the plant compact and attractive.

Winter Care: Pelargonium ‘Citrosum’ is frost-sensitive and cannot tolerate freezing temperatures. In colder climates (Zones 8b and below), bring the plant indoors before the first frost and overwinter it in a bright, cool location. Reduce watering during this period, and resume regular care in the spring when the risk of frost has passed.

Propagation

Pelargonium ‘Citrosum’ can be propagated through softwood cuttings, typically taken in spring, late summer, or early autumn. Here’s how to do it:

1. Select a Healthy Stem: Choose a healthy, non-flowering stem with at least 2-3 sets of leaves. The cutting should be about 4-6 inches (10-15 cm) long.
2. Prepare the Cutting: Remove the lower leaves, leaving just the top set of leaves intact. If the remaining leaves are large, trim them in half to reduce moisture loss.
3. Rooting Medium: Fill a small pot with a well-draining potting mix, such as a blend of peat and perlite or sand. Moisten the mix slightly.
4. Plant the Cutting: Dip the cut end of the stem in rooting hormone (optional) and insert it into the prepared potting mix, burying about 1-2 inches (2.5-5 cm) of the stem.
5. Care for the Cutting: Place the pot in a bright location with indirect sunlight and keep the soil lightly moist. Covering the cutting with a plastic bag can help retain humidity, but ensure the bag does not touch the leaves.
6. Transplanting: After 4-6 weeks, the cutting should have developed roots. You can test this by gently tugging on the stem—if you feel resistance, roots have formed. Once rooted, transplant the new plant into a larger pot or directly into the garden.

Pests and Diseases

Pelargonium ‘Citrosum’ is generally hardy and disease-free when provided with good air circulation and proper watering practices. However, it can be susceptible to pests such as glasshouse whiteflies, caterpillars, glasshouse leafhoppers, aphids, vine weevils, and root mealybugs. Regular inspection and prompt action are key to preventing infestations. Use insecticidal soap or neem oil to control pests if necessary.

Conclusion

Pelargonium ‘Citrosum’ is a versatile and attractive plant that brings both aesthetic and sensory appeal to any garden. While its reputation as a mosquito repellent may be overstated, its lemon-scented foliage and delicate flowers make it a valuable addition to patios, containers, and garden beds. With proper care and attention, this plant can thrive as a perennial in warmer climates or as an annual in cooler regions, providing enjoyment throughout the growing season.