Concrete planters are a functional part of a perennial garden or yard. They are solid enough to hold soil and large plants without being knocked around by the weather. The patina they take on after being out a few seasons gives a sense of maturity to the yard. Once in a while though, they will crack. If it is a simple break without too many side cracks, it can be repaired.
Clean off the surfaces on the insides of the crack with a stiff brush. If the planter has been cracked open, lay both parts down and clean the cracked surfaces. It is important to remove all the crumbling concrete or the new mortar will not be able to grip the old concrete. Wipe away any dust or grit with a damp rag.
Place a thick bead of the mortar on both sides of the crack and pull the planter together. Use strips of cloth to hold the planter together. You can use duct tape, but it will not stick to the concrete so you will have to wrap it around and over on itself so it will stick to itself.
Use your trowel to smooth out the edges of the crack on the inside and on the outside of the planter, adding more mortar if necessary. It will help if you overlay the mortar onto the outside of the planter about half an inch on either side of the crack so that the concrete can get a better bond.
Allow the repaired planter to dry for the recommended time on the packaging of the repair mortar, usually at least 24 hours. Remove the cloth strips or duct tape. If you are planning on painting or sealing the planter, wait at least a week to make sure the repair has dried thoroughly. Your planter should now be ready for use.
Remove the cloth strips or duct tape. If you are planning on painting or sealing the planter, wait at least a week to make sure the repair has dried thoroughly. Your planter should now be ready for use.