Transplanting or repotting a spiny cactus can be daunting. Gloves offer little protection, as spines often poke right through them, and tongs can damage the plant’s skin or break its spines. But several kinds of everyday material make for excellent cacti-grippers. Newspapers, magazines, and brown paper bags, layered several sheets thick, generally work well, but the extremely sharp, strong spines of certain species will tear right through them. For the fiercest of the fierce, pieces of plastic foam packaging are the only way to go.
Because cacti grow slowly, and their root systems are usually small and shallow, they don’t require frequent repotting. For the same reason, when moving day does arrive, the new container needn’t be very much bigger than the current one. Be sure to choose one with a drainage hole and use a porous potting mix. A topdressing of sand or fine gravel guards against stem rot and creates a finished look.
Repotting a Cactus, Step by Step:
1. Moving On Up
When a cactus , be it round or columnar, looks out of proportion in its current pot and could be easily knocked over, it’s time to repot. The new pot should be just an inch or two wider and taller. It will provide sturdy support and ample space for a few years, because cacti grow slowly.
2. Grip It
Even the sharpest spines won’t pierce through foam packing material. Grip the cactus between two pieces and pull gently but firmly. If the plant resists, run a knife between the soil and the pot to loosen it.
3. Radical Roots
Line the new pot with broken crocks, which will aid drainage, and fill it halfway with soil. Use commercial cactus mix, or add coarse sand or grit to general potting soil. Lower the cactus into the pot.
4. Hands On
Fill the space around the roots with soil, tamping down gently. The spines at the base of a cactus are usually finer and more flexible than those on the rest of the plant-they don’t pose much threat to bare hands. Wait a few days before watering a freshly transplanted cactus to allow roots and soil time to settle.