It's a smart idea to give babies and toddlers a healthy diet of organic food, since pesticides and herbicides can harm their developing brains and nervous systems. But once they grow up and are running around the house, it's still important to think organic. Conventional apples, for example, have the highest level of pesticide residue of all commercially grown fruit, so organic apple sauce is much better for kids. The risk of harm to children is still higher than adults, since kids eat more fruits and veggies relative to their body weight.

It's Arbor Day! One of the greenest things you can do to help the planet is to plant a tree. The National Arbor Day Foundation wants to make it easy for you to help the environment and beautify your yard. When you sign up for a six-month membership ($10), the nonprofit will send you 10 free trees to plant. You can also choose to send your free trees to a threatened rain forest or to one of the nation's national parks instead. To learn more, visit arborday.org.

When buying canned tuna, there are no standards for certified organic, so look for brands that use sustainable methods for capture, like pole and line fishing. These types of fishing are laborious, but they prevent other animals like sea turtles from being caught. These methods also capture smaller tuna, which naturally have less mercury than larger ones, making it a healthier choice.