Broadly speaking, there are three different strategies you can use for garden pest control: physical controls, live controls and packaged controls. Each has advantages and disadvantages, strengths and limitations. The one that will work best for you depends largely on the type of garden you have and the type of pest you're trying to stop.
To implement these strategies, you have two choices: do it yourself, or hire pest control services. If you prefer a particular technique, seek pest control services that specialize in that particular approach; many traditional exterminators who rely on pesticides, for example, won't have a lot of experience with organic pest control techniques.
Physical pest control works by manually removing the animals or insects that are posing the problem. This approach can be extremely effective when you're dealing with certain types of pests. For example, pouring used cat litter down mole holes will quickly make them find another place to live, and the larvae of cottonwood borers can be cut right out of trees or shrubs with a pocket knife. You can also use soil covers around your plants' roots to prevent maggots from reaching them.
Live pest control harnesses the power of nature to eliminate problem insects. You can introduce insects that feed on the insects that are destroying your plants. As an example, consider adding ladybugs, lacewings and praying mantises to your lawn or garden if you have a problem with aphids; all three of those insects eat aphids and can provide effective relief. If mosquito control is your particular issue, consider building a bat house on your property; bats eat insects and feed around dusk or after dark, when mosquitoes may be particularly abundant.
You can also achieve lawn pest control through the use of chemicals or other packaged pest control products. If you opt to go this route, try non-toxic products before turning to stronger chemicals. Be cautious when using this approach, too; some chemicals kill everything in their path, even beneficial insects, which can cause even bigger problems down the road.
Electronic pest control techniques have become increasingly popular in recent years, but there's still some question as to how effective they really are. This approach uses ultrasonic frequencies that only insects can hear and which create an unbearable environment for them, thus driving them away.
Most organic pest control products use common, all-natural and nontoxic substances, such as citric acid or garlic, to kill pests. Various oils, including sesame oil, thyme oil and clove oil, also form the base of many organic alternatives to harsh chemicals. At the very least, they're worth a try; under the right circumstances, they can provide effective relief from pest infestations without damaging your garden environment.