Container Size for a Cactus

Container Size

• There is no set schedule for repotting a cactus. However, gardeners generally repot their cactus plants in the spring, according to the University of Nebraska. A cactus needs a new container when it has grown within 1/4 inch of the sides of its container. The new container size that you choose should be only slightly larger than its current container. Before purchasing a new container or choosing another one, measure the diameter and depth of your current container to get the right size.

Preparing Repotting

• Mix up your planting medium in a bucket. Use one third garden soil, one third peat moss and one third builder's sand. Avoid using the garden soil in your yard. Use a sterilized potting soil. Garden soil may contain diseases or harmful pathogens for your cactus. Fill the container a third of the way with the potting medium. Lift the cactus out of the former container. Check the root system to make sure that the container you chose will fit its growing characteristics. For example, species of cacti that have lateral root growth need wider containers. Pick another container if the one you have chosen is too narrow.

Potting

• Place the cactus inside of the container. Make sure that it is set at the same depth as it was growing in its former container. Pack soil around the plant. Avoid packing the soil too far up the trunk of the cactus. Set your cactus on a saucer filled with 1/2 inch of pea gravel. Not only is the size of your container important, but the saucer you choose must be large enough to accommodate the size of your container.

Other Considerations

• Use containers that are made from terracotta or clay to prevent the soil from getting too moist. After transplanting the cactus to the new container, wait a few days to apply water. Moving a cactus from one container to the next can damage its root systems. Watering damaged root systems may lead to fungal diseases. Avoid watering to allow the root systems to heal. When you water your cactus, use lukewarm water to prevent shocking the plant, as recommended by the University of Nebraska.