Concrete planters are a common feature in many gardens and yards. They are functional and decorative, allowing gardeners to plant flowers or foliage in them while enhancing interest and appeal of a particular spot. Although concrete planters are sturdy and cannot be knocked over easily by strong winds, sometimes they crack. Repairing a crack is a simple procedure you can do to continue enjoying your container garden.
Empty the cracked planter's contents to a temporary pot, and hose it down to remove any crack residue.
Scrub the crack's surface with a stiff brush to remove any loose pieces. Clean all the large broken pieces if the planter has been completely cracked open. Try to remove all loose and crumbling concrete pieces so the fresh mortar you apply adheres to the surface easily. Allow the planter to dry thoroughly.
Apply a thick layer of mortar around the crack with a trowel, covering it completely. Allow an overlay of one-half inch around the crack on both sides of the planter. The mortar acts as an adhesive to hold the broken planter pieces together, and the overlay will encourage a better bond. Push the mortar inside the crack with a putty knife, and pull the cracked pieces toward each other.
Wrap damp cloth strips around the planter as tightly as possible so they hold the crack together while the mortar dries. The size of the cloth strips depends on the size of the planter. Wind each strip tightly around the planter to cover the crack, and knot it.
You can substitute duct tape for cloth strips, but you will have to apply several layers so they stick to one another to hold the crack together, as the tape's adhesive does not adhere to concrete easily.
Follow label instructions on the repair mortar, and wait for the recommended time, which is usually 24 hours.
Remove the cloth strips or duct tape carefully. If the knots on the cloth are tight, cut them in the center with scissors. Although your crack is now sealed, do not fill the planter with soil and plants for three to four days to allow the mortar time to cure.