Mosquito Repellent Plants

Plants like catnip can keep mosquitos at bay.

Mosquitoes are among the most common and annoying insect pests. Although the synthetic chemical DEET will repel mosquitoes, many environmentally-conscious people prefer not to use a chemical repellent. For these people, a better choice is to plant mosquito repellent plants. The plants or their essential oils will keep those pesky insects away.

Catnip

Catnip (Nepeta cataria) is best known for its attractiveness to felines, but it also repels mosquitoes. In fact, the essential oil in the plant -- nepetalactone -- works more effectively against mosquitoes than DEET, the main ingredient in many insect repellents. Catnip is a perennial herb that grows well in USDA zones 6 through 10. The plant needs full sun to partial shade and rich, well-draining soil.

Citronella or Lemon Grass

Citronella is the essential oil found in lemon grass (Cymbopogon nardus). Most home gardeners are aware of the mosquito repellent properties of this substance. Candles are often made with citronella and sold as insect repellents. This tropical ornamental grass forms attractive clumps of wide, green leaves and thrives in USDA zones 10 through 12. The plant needs full sun and plenty of water (up to 30 inches per year) to grow well.

Vanieenii Scented Geranium

This variety of geranium (Pelargonium citrosum "Vanieenii") features foliage with a strong citronella scent. Placing this geranium near doors and windows helps keep mosquitoes away, according to information from the Colorado State University Extension's website. This plant is also attractive, with lacy foliage and soft purple flowers. Like other geraniums, they thrive in almost any growing zone as annuals, but are perennial in USDA zones 7 through 11. Outdoors, they grow best in partial shade with cool, moist soil. Indoors, they thrive in bright but indirect sunlight.

Lemon Thyme

Lemon thyme (Thymus x citriodorus) is another fragrant herb that repels mosquitoes. This inexpensive and cold-hardy plant can be grown in USDA zones 5 through 8 outdoors, or it can be grown indoors. The herb thrives in full sunlight and loose, rocky soils that are on the dry side. It has a pleasant lemony scent and can be used in cooking.

Lavender

Lavender (Lavandula angustifolia) is desirable for its attractiveness and pleasant fragrance. The tall stalks of purple flowers are not only showy, but the essential oil that gives the plant its distinctive scent is also a mosquito repellent. Lavender grows best in USDA zones 5 through 9 in full or partial sun and in soil that is rich and consistently moist.

References

• Colorado State University Extension: Plants Help Keep Mosquitoes Away
• "Bug Off; Jerry Baker"; 2004
• Science Daily; Catnip Repels Mosquitoes More Effectively Than DEET; Chris Peterson, Ph.D., et.al.; August 2001
• Alderleaf Wilderness College; Plants That Repel Mosquitoes; Jason Knight
• University of Oklahoma Plant of the Week; Nepeta cataria - Catnip or Catmint; Cal Lemke
• Floridata: Cymbopogon nardus