Is there really a plant that will ward off mosquitoes, and if so, what is the name and is it available in the Seattle area?
There is disagreement about the extent to which certain plants repel mosquitoes. Below, please find some web sites that highlight some plants that may work.
There are eleven plants generally thought to repel mosquitoes:
Citronella, Eucalyptus, Pennyroyal, Rosemary, Rue, and Wormwood. Milder ones (in our experience) include Basil, Bay, Lavender, Sage and Thyme. With even the smallest of herb gardens, or access to a supermarket selling freshly-cut herbs, the leaves of such plants can simply be rubbed on pets and people to temporarily ward off insect attacks.
(Source: Janette Grainger & Connie Moore. Natural Insect Repellents for Pets, People & Plants. 1991, p.11.)
According to Donald Lewis of the Department of Entomology at Iowa State University, citrosa, lemon thyme or citronella grass may help repel mosquitoes, but you have to crush the leaves and rub them on your skin to make them work.
According to the MadSci Network, citronella oil may be more effective at repelling mosquitoes than the plant itself.
Lastly, Colorado State Cooperative Extension recommends scented geranium, lemon grass and a host of other plants.
There are many local nurseries which may carry the plants mentioned above, but since inventory changes frequently and they do not list their inventory online, it is best to give them a call to find out if plants you are seeking are available.
Because of the ongoing concern about West Nile Virus, there is a lot of information available on ways to control mosquitoes. See King County Public Health’s resources on this topic.