Rain has finally come to Lubbock, temperatures have abated somewhat and we can get back into the garden. Joining us in the garden will be those annoying mosquitoes.
Mosquitoes are a prolific pest with over 3,000 species worldwide and 200 species in the United States (mosquito.org). They need water to survive and thrive in any environment except extreme cold. The kind of mosquito around now is likely the permanent water mosquito, the house mosquito.
The house mosquito's lifecycle begins with the female laying eggs in as little as one-inch of water. The eggs hatch and larvae are released. These "wigglers" can be seen in water-filled buckets, when it seems as if the surface of the water is in motion. After larvae pupate, adults emerge from the water in about four days. Fully developed males locate females by the sound of her wingbeats. It is the females we hear buzzing as she seeks blood. Females mate once but continue to lay eggs after every blood meal. Females live for a month or more.
The most opportune time to rid your garden of mosquitoes is the larval stage. Once adults are released, harsh chemical body sprays repel them, but can organic alternatives such as mosquito-repelling plants deter these pests?
There are botanic groupings of plants reported to thwart mosquitoes. Most suggest plant species that emit citrusy volatiles. Included in most groupings are scented geraniums (Pelargonium spp.), which have deeply lobed, ruffled, light grey-green fuzzy foliage with fragrances that are reminiscent of citrus, rose, nuts, mint to coconut.
Of the many scented geraniums there are several that emit citrus odors: Lime geranium (Pelargonium nervosum) has lime-scented leaves; Lemon geranium (Pelargonium crispum), with lemony aroma and Variegated Lemon geranium (Pelargonium crispum “Variegatum”), with white-edged leaves; Citronella geranium (Pelargonium citronellum) that emits an odor of citronella grass; and Citrosa geranium (Pelargonium citrosum "Van Leeni") with a strong lemon scent.
Pelargonium citrosum is the usual cultivar marketed variously as the "mosquito plant,” citronella plant, citronella geranium, mosquito plant geranium and citrosa geranium. While its common names give the impression this species contains citronella, the ingredient in insect repellents, it is actually just a scented geranium that produces citronella-like scent when leaves are crushed.
So the question remains: Does the citronella geranium repel mosquitoes? Leaves must be crushed to release the citron oil and when volatized emit a citron smell. Rubbing crushed leaves on the skin may provide some immediate but not long-lasting deterrent (Journal American Mosquito Control Oct, 1994). However, take care, as some people are sensitive to the geranium when it comes in contact with the skin, so test a small patch of skin before you take this approach.
Scented geraniums are still a wonderful addition to the garden, offering a pleasant aroma when brushed against, are easy to grow, make attractive container plants with their ruffled leaves, are fairly drought tolerant. Avoid overwatering.
So have fun with them by adding to your garden.
Some information from mosquitoworld.net; Fine Gardening
ELLEN PEFFLEY taught horticulture at the college level for 28 years, 25 of those at Texas Tech, during which time she developed two onion varieties. She is now the sole proprietor of From the Garden, a market garden farmette. You can email her at email@example.com.