How do you get rid of fleas in the yard?

Get a good pesticide concentrate and fill a hose end sprayer. Set the dial to 1 ounce per gallon and spray your yard outside. Keep sprinklers off for a day or 2. If you have pets put flea collars on them or give them a flea bath at about the same time.

A greener way would be to spray your yard with nicotine tea. You can make this yourself (I'll leave the recipe below). The only thing to consider is that this will kill all insects in your yard, and it would be a good idea to keep the cat and dog out of the yard for a couple days.

Nicotine Tea:

1 lb. loose tobacco (type does not matter, the cheapest will do).

Water.

1. Boil two quarts of water
2. To the water, add one cup of loose tobacco
3. Allow to steep and cool.
4. Place a coffee filter in a funnel or wire basket and filter the water through it into a large enough container to hold it. I prefer a gas can, and have mixed up as much as a gallon or two at a time.
5. Place the nicotine tea in a sprayer, and beginning along the edge of your home, spray in a spiral pattern outward.

Some people will use the tea prepared this way as a concentrate, and mix it one for one with water. Others use chewing tobacco, and you may want to consider this if you are spraying around tomatoes (Tomatoes are susceptible to the Tobacco Mosaic Virus, which is essentially dead in North America, but may be carried in Turkish tobaccos).

Nicotine tea will kill most insects within minutes of contact. It is organic, so will be absorbed into the environment more redily than other chemical pesticides. And, is largely harmless to humans (except if drank--don't do this and keep it away from children).