Is your favorite houseplant flourishing or flagging? It might be getting too big for its britches. Transferring to a larger pot is a good opportunity for pruning the roots, which is the secret to a well-kept and happy houseplant. It sounds severe, but by trimming the roots and the tops, the plant spends more energy developing new roots — and less effort to grow bigger and stronger. How often a plant gets pruned depends on the plant, yet some varieties will need pruning every year, while slower growing plants can go years without any pruning at all. Usually you can tell by the growth of the plant or look at the root ball, and check to see if it's a tightly wound, gnarly mess, and you'll know that your plant will appreciate root pruning. Here's what I do:
1. The night before “surgery” water the plant well and allow the water to drain thoroughly. The next day remove the plant from its container. Using a sharp knife (take a deep breath) start trimming a ½-inch from the entire root ball. Gently detangle and loosen the roots. You can do this with a bamboo chopstick, a pencil, or something similar. Cut away any decaying or discolored roots.
2. If you plan to use the same pot, sterilize the original container by washing it with a solution of 1 part bleach mixed with 9 parts water. Partially fill the pot with new, preferably organic, potting soil, and gently place the plant back in the pot. Press more soil around the roots, and continue to fill to just below the lip of the pot. Place pot on a saucer and water thoroughly until the soil is soaked.
3. It's essential to trim the top, as well, which keeps the whole plant in sync. Cut back ¼ of the stems from the top growth to the soil surface. Place pruned plant in a cool room, away from direct sunlight. Don't be surprised to see the plant go into mild shock, give it a couple of weeks to recover from surgery! Also it's important to keep the soil on the moist side for the first two weeks.
4. Once adjusted, place plant back in its original location and off it goes! Feed the plant by adding fertilizer to the water after about four weeks. If using water-soluble fertilizer cut dosage to 50 percent strength initially.