Organic produce is the best choice for juicing, and growing fruits and vegetables in your backyard garden is the easiest way to ensure they haven't been contaminated by dangerous herbicides or pesticides. If you don't have the time or space to grow your own, purchase locally or regionally grown organic produce in your local health food store, farmer's market, or supermarket. Organic produce doesn't expose you to the dangerous chemicals used in commercial agriculture, ensuring that you'll get maximum nutrients from the fruits and vegetables you juice.