If you want to kill fleas in your grass, you have to consider the life cycle of a flea. Most people are concerned with killing the adult flea but if you really want to tackle the problem you have to attack fleas in all four stages.
The fleaâ€™s life cycle includes egg, larvae, pupa and adult. In the egg, larvae and adult stage, fleas can be pretty easily eradicated. In the pupa stage, they are practically invincible so any treatment you use may need to be re-applied in 7-10 days, after the pupa have hatched.
To treat your yard, start with a spray. Cover the yard as completely as possible. After the spray, a granule should be used. The granules will activate the first time they get wet. Unless the weather calls for a Florida deluge, the granules should continue to work for up to one month.
A safe, more natural, form of spray and granule is a Pyrethrin. Pyrethrin is a natural compound made from Chrysanthemums.
If conditions are right, the first application of spray and granules should wipe out the fleas.
During the day, fleas like to hide in the shade. They can also be found in dry, shady areas like outdoor sheds. If you have a crawl space under your home that is big enough for animals to get into, this will be their favorite spot as it is shady and dry and little host critters are always coming to visit. Fallen leaves under trees also make a great hiding spot for fleas.
Help prevent fleas from becoming a problem in your yard in the first place by cleaning up the leaves, treating the shed (and keeping Fido out of it) and blocking off any crawl spaces you might have under your home. An ounce of prevention can go a long way.