Watering gardens uses a considerable amount of water. Miami-Dade County in South Florida has water conservation facts that are pretty surprising. Sadly, the average American uses 100 gallons of water per day, and more than 50% of that is for outdoor use.

One inch of rain on a 1,000-square-foot roof will yield around 600 gallons of water. According to the Florida Department of Environmental Protection, the state receives 54 inches of rainfall annually. Most of this rainwater is not harnessed, and it is left to fall off roofs and wash dirt and chemicals like pesticides and fertilizers into sewers, local ponds, rivers and waterways.

In South Florida, the University of Florida’s extension campus is offering rain barrel workshops to aid residents in conserving water and making rain barrel systems in their own back yards. The workshops cost $45 to attend, and the price includes not only the class, but also a rain barrel and a hose bibb. If you don’t want the supplies, you can pay $10 just for the class. There is usually a workshop held once a month at the Coral Gables Farmers Market.

If you can’t afford to attend a class on rain barrels or just don’t have the time, there are other ways to learn to conserve water safely. Bloggers Carol Buie-Jackson and Jay Jackson of North Carolina own the blog Smell Like Dirt, which posts many sustainable gardening, composting and water reuse tips for green-thumbed environmentalists. Carol’s rain barrel video shows gardeners how to convert their rain gutters into water-saving tools.

According to Miami-Dade's website, it is best to water your outdoor plants in the early morning, between 5 and 8 a.m. If you water your plants when it's hot and sunny out, a lot of the water you use will evaporate before plants can take it in. The county's website also has good tips on environmentally friendly landscaping, including reducing storm water runoff, protecting natural waterfronts and water efficiency.

You don't have to live in Florida to enjoy rain barrel classes and the benefits of collecting your own water. Many other cities offer rain barrel classes. Chicago's Department of Environment website gives detailed instructions on building rain barrels for environmentally conscious gardening. Chicago Botanic Garden held a rain barrel painting competition in September 2009 for children ages 8 to 18. Lincoln, NE, residents can take a rain barrel class at Southeast Community College for $49 and all supplies are provided. In Santa Fe, NM, if you purchase a rain barrel, you can get a rebate from the government. In Dallas, residents can attend a rain barrel class for $40, which includes the rain barrel supplies.