Remove a prickly pear pad that is at least six months old with your knife.
Sit the pad upright so it will not curl while a callous forms over the wound. In warm weather, a callous will form on the cut in one or two weeks. This will take longer in humid conditions. To avoid rot, allow more time rather than less.
Dip the cured pad in a Bordeaux mixture to protect it from fungal infection. You can make an amount of Bordeaux mixture suitable for home gardening by adding 3 1/3 tablespoons of copper sulfate and 10 tablespoons of dry hydrated lime, available at most garden centers, to 1 gallon of water.
Plant the pad upright about 1 inch deep in a mixture of 1 part sand or rough pumice and 1 part soil. Use rocks to anchor the pad and keep it upright. Do not water it. Prickly pear pads contain moisture, enabling them to sprout roots. If you water a pad at this point, it may rot.
Water the pad after one month when roots have formed, and it will stand upright by itself. Do not water again until the soil is dry.
Water and Fertilizer
Water only when the soil is dry. When prickly pear cacti are dormant in the winter, water only enough to keep the pads from shriveling, and make sure they get plenty of sunlight.
Apply a balanced fertilizer monthly during their spring to fall growing period. A balanced fertilizer contains equal amounts by weight of nitrogen, phosphorus and potassium.
Fertilize with a high-nitrogen fertilizer if you want larger pads.
Fertilize with a product that does not contain nitrogen if you want your cacti to produce flowers and edible fruits. Apply monthly even during the winter when the plants are dormant.