You have four choices when looking for landscaping products:

Home Improvement Stores and Lumber Yards

Home Depot not only has tools, lumber, electrical and plumbing materials, but also has a garden center. Lumber yards have tools, lumber, electrical, and plumbing materials, and also have landscaping items like gravel and sand.

Nurseries/Garden Centers

Nurseries and garden centers will have the largest selection of trees, shrubs, and bedding plants. You may also have nurseries in your area that specialize in native plants, trees, or bonsai plants.

Specialty Retail Stores

There are a number of specialty stores in your area that may sell products that you'll need to landscape your home. Examples of these types of stores are stores that sell fountains and stores that sell ceramic tile.

Landscape Products Etailers

There are many online companies that sell products used in landscaping. These etailers include Timberwall.com and LandscapeProducts.com.