How to Pot a Barrel Cactus

Choose a pot that is 2 inches greater in diameter than the barrel cactus. Terra cotta, pottery, plastic, metal and wood all make good planting pot materials as long as the pot has one or more holes in the bottom for drainage.

Fill the bottom of the pot with a 1/2- to 1-inch layer of gravel. Use gravel slightly larger than the drain holes in the bottom or, on large pots with bigger holes, place a piece of pottery or a flat rock over the holes before adding the gravel.

Add a soil mix that consists of one part sand, one part peat moss and one part perlite on top of the gravel layer to fill the pot half full.

Put on heavy leather gloves before handling the cactus to protect your hands from the sharp spines. Slide the barrel cactus out of the nursery pot or out of its current pot, and place it in the new planting pot.

Hold the cactus so that the area where the roots and the stem join is 1/4 to 1/2 inch below the lip of the pot. Remove soil from under the roots or add more soil as necessary until the cactus sits on its own at the right level. Fill the pot to the base of the cactus stem with additional soil mix.

Press down gently on the soil with your fingertips. Run water slowly into the container until it fills the space between the top of the soil line and the lip of the pot and allow the water to drain through. Place the potted barrel cactus in a spot that gets full, bright sunlight.