Lime kills fleas by drying up their bodies. However, using lime for such a purpose is recommended only a last resort, as it burns the skin and destroys lawns. Lime also causes fleas to die from sun exposure as the grass recedes. Gardeners should sprinkle the lime in an even fashion across the lawn.
Agricultural lime is another alternative that dries out fleas and their larvae. This form of lime is used as a mild pesticide by gardeners and farmers. It is mixed with water for easy distribution, and it can be sprayed on other plants. Garden Guides suggests raking up garden debris and disposing of it in a bag before applying agricultural lime. Burning the pile is another option. Moist and grassy areas are lucrative breeding areas for fleas. The flea larvae can remain dormant for around 90 days before emerging.
Because of its corrosive nature, animals and humans should have minimal contact with lime. While the substance is a normal ingredient found in garden and lawn maintenance products, it is only capable of killing fleas when used in large quantities. Mask and eye protection must be worn when applying the agent in dust or powder form, since it burns the eyes and lungs. Burning of the eyes and skin is more likely in places where excess moisture is present. Enclosed shoes, gloves, long-sleeved shirts and long pants should be worn during application.