How to Repot Houseplants
When houseplants outgrow their pots, their root systems may not be able to derive the water and nutrients needed to support the top growth. When that happens, plants tend to become stunted and the older leaves may lose their color and drop. The solution: transplanting the plants to bigger pots. And it's best-done in the spring, when roots grow most actively, allowing the plant to quickly overcome the shock associated with repotting.
Not all houseplants need to be repotted every year -- some can go for several years without being repotted if they're top-dressed at least once a year -- but you'll notice a big difference in their health if you do take the time to do it every year.
If you don't want the plant to grow larger, you can prune its roots instead of repotting. Trim the outer inch or two of roots with a sharp pruner, and place the plant in its original container. Add fresh soil mix to fill the pot and water well. You might also consider pruning the top growth a little so that it's in proportion to the newly downsized root system. Keep in mind, though, that not all plants take well to this method. Avoid pruning top growth on peace lilies, Norfork Island pines, and cacti and other succulents, ferns and other plants that send up leaves directly from the soil line.
And if you have houseplants that are simply too large to repot, such as a banana tree or a sago palm, your best bet is to top-dress them with fresh potting mix. Begin by removing the top inch or two of soil mix. Be careful not to damage too many of the surface roots. Apply a fresh layer of soil mix, packing it gently as you go, and water well.
Here's how to repot a plant:
Materials and Tools:
new pot (no more than 2 inches in diameter larger than the old pot)
1. Water the plant well three or four days before repotting. Since repotting is a messy job, you might consider tackling the task outdoors. Just make sure the weather is warm enough -- in the 60s -- or the plant may go into shock.
2. Invert the pot and gently remove the plant by grasping the main stem. Give it a slight tug and it should slip out of the pot. If it doesn't, use a butter knife or other flat-bladed tool to loosen the sides of the pot and try again.
3. Add fresh potting soil to the bottom of the new pot, packing it well around the drainage hole. Then transfer the plant to the new pot. Adjust the amount of soil mix so that the plant is at the same level as it was in the old pot. Position the plant, add soil mix to fill, and water well.
4. After a plant has been repotted or top-dressed, it may show signs of stress -- the most obvious sign is wilting. It's a good idea to keep the plant out of strong light for a week or so to give it a chance to rest and rebound.