Pests such as insects can be extremely irritating around the home and garden. Some people choose to apply pesticides, chemicals which kill the unwanted visitors, but pesticides can have a negative impact on the health of plants, humans, other animals, and the environment. As a result, some consumers choose to use natural pesticides derived from plant extracts. Many of these natural pesticides are just as effective as their chemical counterparts, but they are far less toxic. Non-harmful pesticides are also an important part of organic and natural gardening.
Caution should be used when applying natural pesticides around animals and children. Although they are less toxic, many natural pesticides should not, ideally, be consumed by growing humans and household pets. It is also important to apply natural pesticides during a period of low bee activity, as bees are highly beneficial for the garden. The best time to do this is in the evening, giving the plant around 12 hours to absorb the protective pesticide before the bees come out.
Most natural pesticides are derived from plants. Three of the most toxic are pyrethrins, derived from chrysanthemums, sabadilla, and nicotine. All can be applied directly to certain plants, or to insects, and they cause death in a short period of time. However, they are highly toxic to other animals as well, and the containers should be kept in a high, secured area. After using these natural pesticides, always wash your hands thoroughly.
Less toxic but still effective plant derived pesticides include oxalic acid teas made from things like rhubarb and raspberry leaves, garlic spray, nightshade teas made with the leaves of tomatoes and potatoes, and neem oil. All of these substances can be applied directly to plants, and they act in various way to disrupt the life cycles of garden pests. Caution should be used with neem oil, which smells very strong. Another option is citrus oil, which is used to deter pests.
Some natural pesticides are derived from mineral ingredients. The most common example is diatomaceous earth, which is actually the pulverized fossils of sea creatures called diatoms. Diatomaceous earth will eat through the exoskeletons of pests, and ultimately into their bodies. Outside, it can be applied loosely around the garden as long as you have no pets or children, and it can also be used indoors to control fleas and household pests, as long as the area is cleaned and vacuumed afterwards, as it can irritate the lungs. It is recommended that you wear nose and mouth protection while applying diatomaceous earth.