Q. What is the best way to repot a cactus?
A. Cacti should be repotted when they outgrow their containers or become root-bound. When plants become root-bound, they fail to absorb nutrients and produce little growth. It is best to repot a cactus into a container only slightly larger than the container it has outgrown. Choose a container with adequate drainage holes to allow water to drain from the pot. To protect your hands when transplanting cacti, it is helpful to wrap the plant in a thick layer of newspaper to aid in removing it from the pot. Thick leather or rubber-coated gloves will also protect hands while transplanting. Use a potting mix formulated for cacti. Sharp soil, small pebbles, or grit can be added to the mix for better drainage.
Repotting your cactus is in many ways very similar to repotting almost any other houseplant.
- Begin by filling the new pot ½ to ¾ full with soil.
- Remove your plant from its old pot.
- Make sure to wear gloves.
- Roll up a sheet of newspaper to make a strip approximately the same width as a belt.
- Wrap your newspaper strip around the plant and use it as a handle to gently lift the plant from the pot.
- If the plant is really root-bound, gently loosen the soil around it to encourage new growth. (I like to leave some of the soil intact. This provides some weight to help keep the plant anchored. If the soil is of poor quality, all of it should be removed.)
- Using the newspaper handle, set your plant into its new pot.
- Using a chopstick, firm the soil around the base of your plant. Keep adding soil until it reaches the same level as the old soil. (This should be approximately ½-1 inch below the lip of the container.)
- Water your plant throughly.
Your cactus now has much more room to grow, which also means much more soil to stay moist. Make sure to check before watering again—the soil can stay moist for a long time, even if it is a mix made for cacti.