Spiders are more beneficial than they are dangerous. The majority of spiders are harmless and of use to people because they feed on mites and insects. The contribution that spiders make certainly outweighs their limited potential health hazard. Using pesticides for long term spider control, including chemical spraying, is typically not effective and can be dangerous. Fortunately, you can use a number of basic pesticide-free techniques to control spiders.
Approximately 3,000 different spider types inhabit North America. Very few of these species are dangerous to humans. Tarantulas, which inhabit the southern United States, are considered by many people to be dangerous, but these large spiders are mainly harmless. The bite of a tarantula does not cause lasting discomfort, although sensitive people may experience an allergic reaction to their hairs. You can take a number of precautions to discourage spiders from entering you home. Seal any cracks in the foundations of a home, together with those around doors and windows. Chalk up the places where electrical cables and water pipes enter the building.
Remove spiders physically from indoors or from your garden, by placing a glass jar or similar container over them. Slip a piece of paper under the container -- it will seal it sufficiently enough to allow it to be picked up and moved. Use a vacuum cleaner to remove both potentially dangerous spiders and their webs. Spiders are soft bodied and will not survive this procedure. Crush dangerous spiders, such as the black widow, brown recluse and hobo with a fly swatter, broom or rolled up piece of newspaper.
According to the University of California, pesticides do not provide long-term control of spiders. Washington State University Extension concurs that the majority of spider problems can be overcome without resorting to the use of chemicals. Home owners should not have piles of debris or wood near the house. Flower beds should also not be placed immediately next to the foundations of a building. In storage areas, put boxes up off the floor and away from walls. It is best not to position outdoor lights close to the house, as these attract insects at night, which in turn attract spiders.
A number of organic pesticides will discourage spiders. The scent of citrus is a natural repellent for spiders and lemon, lime and orange peels will keep spiders away. Living mint and lavender plants will also deter spiders, as will chestnuts. Lavender can be planted in indoor pots, as well as in the flower beds which surround the home. Apply a combined chilli pepper and vinegar spray directly to existing webs and spray it around window sills and doorways to deter spiders.