How to Pour Concrete Curb Forms

Define the path of the curb around your landscape feature with a rope. Place the rope at least 10 inches from the edge of the garden or walkway; 4 inches are for the form boards. With a shovel, dig out the grass and soil between the rope and garden 4 inches deep, and tamp the soil at the base of the trench to push out any air pockets and moisture.

Place form boards against the interior walls of each side of the trench. Stack the boards on their sides to reach the desired height for the curb. For instance, if you want the curb to be 4 inches above ground, attach two layers of 2-by-4 inch boards to extend the depth of the trench plus 4 inches above ground.

Nail the boards together using a hammer, and brace the form with 1-by-3-inch garden stakes around the outside of the boards.

Fill the forms with a 3-inch layer of ¾-inch aggregate and tamp it until the surface is hard. The tamped aggregate helps prevent the concrete from cracking and facilitates underground drainage.

Mix ready-mix concrete with water and an iron oxide color pigment in a cement mixer until the batch has a brownie-batter-like texture. The pigment is optional, but it adds color to your curbs, accentuating your landscape or complementing the home.

Pour the concrete, shifting it around with a hoe to spread it into corners. Scrape off excess with a trowel and smooth the top with a float.

Refer to the concrete package instructions for the amount of time you'll need to cure the concrete before removing the forms. Once you remove the forms you can backfill the spaces between the grass and the curb with soil.