Sevin is the brand name of an insecticidal compound called carbaryl, a hazardous chemical that can affect the respiratory system, nervous system, cardiovascular system, reproductive system, as well as blood, skin and the cholinesterase of the body, according to the Center For Disease Control. It can cause blurred vision, nasal discharge, sweating, salivation, nausea, vomiting, diarrhea, tremor, skin irritation and convulsions. Sensitive individuals and those worried about environmental effects may prefer natural alternatives to combat insects in their gardens.
Natural pesticides generally kill insects on contact and breakdown quickly in sunlight. They leave no chemical residues that can runoff into waterways that will cause risks to wildlife and beneficial insects that help to control plant pests.
Insecticidal soaps are mixtures of soap and other ingredients that help to coat insects' bodies, smothering them. Used as a contact insecticide, you must spray them directly on the insect. They have no residual effect on the environment and are considered a relatively safe and easy way to control insects, according to Colorado State University entomologist W.S. Cranshaw. Use no more than a 2 to 3 percent concentration of soap on plants, and test an area of the plant first before applying to ensure that no injury to plant cells occurs.
Neem oil is extracted from the seeds of the neem tree, a native plant of India and Southeast Asia. The active ingredient in neem oil is azadirachtin, which works as a feeding deterrent and also as an insect growth regulator, preventing the development of larva forms. Like other oils, it can cause phytotoxicity, which can damage plants. It should be tested on the plant before using more liberally.
Companion planting is a method of using plants that are known to repel certain insects to help protect other plants. Plants such as cilantro, fennel, Greek oregano and sweet alyssum can attract hoverflies, which feed on aphids that suck plant juices, according to MotherEarthNews. Planting sunflowers will help to attract birds that feed on garden insects to your property.