Citronella has long been heralded as a natural insect repellent and is even the source of common household repellents like candles and sprays.
The citronella plant prefers damp to wet soil which makes it perfect for planting around the edge of your pond. Find an area which enjoys all day sun and plant mature citronella directly into the ground.
The pond water and sunshine will do the rest. The grassy leaves of the citronella plant give off a strong lemony scent which repels pest insects of all kinds.
You may find that the plant dies off during the winter months but should make a comeback as the temperatures rise. If the return seems sluggish or does not occur, replant and enjoy the season. (Reference 4, 5, 3, 9)
Marigolds are a pervasive plant that is considered to be a weed by many. They are also an effective insect repellent which is available in an array of colors and which requires little to no care for successful and annual growth.
Plant marigolds around the rim of your pond in full sun if possible and allow them to propagate naturally. They should not be placed at the water’s edge but a few steps away since overly damp soil will prevent healthy development.
They will spread rather quickly and will return each growing season in full strength. The marigold gives off a light floral odor that the gnat and the mosquito will attempt to avoid. (Reference 4, 5, 3, 10)
Catnip is reported to be better at repelling mosquitoes and other insects than the dreaded and dangerous DEET itself (Reference 2).
Catnip is a form of mint which is native to the UK but is present throughout the United States in nearly all areas.
Catnip does not require any special attention or planting position but it may do better placed a bit of a distance from the edge of the water, where the soil is not as damp.
If you have cats or there are cats in the area, catnip may not be the best choice for you. It causes a reaction similar to a stimulant in felines and may result in unhappy pets and owners. (Reference 5, 1)
An array of wildflowers and plants which are available at the local garden center also help to keep mosquitoes and other flying pests away.
Plants like sagebrush, wild bergamot and mugwort all keep the nasties away, while wild vanilla leaf is native to the American Northwest region and is equally useful.
Pick up some peppermint, rosemary, garlic or clove seeds at the shops and plant them around the pond to create a dual purpose herb garden and insect repellent crop. (Reference 4)
Mosquitoes and other flying pests that breed in the still waters of your pond use aquatic plants as a food source and as a landing zone.
Consider eliminating any plants with foliage that extends above the surface of the water. This strategy, coupled with a ring of insect repelling flora around the edge of the pond can result in a reduction of the habitable area for gnats and as a result, a reduction in their numbers. (Resources 1)
- University of Kentucky: Catnip [http://www.uky.edu/Ag/NewCrops/introsheets/catnip.pdf]
- Iowa State University: Catnip Captures Attention as Natural Mosquito Repellent [http://www.ag.iastate.edu/aginfo/news/catnip.html]
- Mosquito Info: Five Plants that Naturally Repel Mosquitos [http://www.mosquitoinfo.info/five-plants-that-naturally-repel-mosquitoes/]
- Wilderness College: Plants that Repel Mosquitos [http://www.wildernesscollege.com/plants-that-repel-mosquitoes.html]
- Earth Easy: 5 Easy to Grow Mosquito Repelling Plants [http://eartheasy.com/blog/2011/04/5-easy-to-grow-mosquito-repelling-plants/]
- Iowa State University: Mosquito Repellant Plants [http://www.ipm.iastate.edu/ipm/hortnews/1993/5-26-1993/plant.html]
- The Old Farmer’s Almanac: How to Deter Mosquitos and Other Bugs [http://www.almanac.com/content/how-deter-mosquitoes-and-other-bugs]
- Dellwood Homeowners Association: Insect Repelling Plants [http://www.dellwoodhoa.org/wp-content/uploads/2011/05/GlenBagby-plants-insect-repelling1.pdf]
- Botany: Cymbopogon – Citronella Grass [http://www.botany.com/cymbopogon.html]
- Botany: Tagetes – Marigold [http://www.botany.com/tagetes.html]
- University of Kentucky: Midges and Gnats [http://www.ca.uky.edu/entomology/entfacts/entfactpdf/ef632.pdf]
- University of Missouri: Chironomid Midges [http://extension.missouri.edu/explorepdf/agguides/pests/g07402.pdf]
- UC Davis: Noseeums in Feeding Frenzy This Time of Year [http://entomology.ucdavis.edu/news/noseeums.html]