Gardening and Horticulture - retaining wall

I'm not sure if this is the correct forum or not but here's my question: I want to build a retaining wall to create a terraced area to plant some fruit trees and I was wondering if anyone knows of any good resources on the web (or elsewhere) for building such a wall. It needs to be about 3-4 feet high, 40 feet long, and I don't particularly care how it looks because it won't be visible from my house. Thanks for any advice.

First, check with your local zoning board to see if you need a permit to build a retaining wall - esp. since you are proposing one that is 3-4' high.

Secondly, retaining walls might be a lot harder to install than you think - a solid footing is required, or else the wall will fall over, creating a possible hazzard and liability in the process. The depth of the footing depends on where you live and how high the wall is.

Lastly, retaining walls can be really expensive to build. Since you are planting fruit trees, you might want to consider simply planting on the slope.

If you still want to persue the retaining wall option, check out your local building supply store; they probably have some guides (since they want you to buy their materials). Be sure to check at your local government offices, too, to see what rules may apply.