Getting through our long winters is a lot easier when you make your indoor environment a little more inviting with houseplants. If youre successful keeping your plants alive and well, sooner or later youre going to have to think about repotting them. Proper watering is the most important aspect to helping your houseplants thrive. How much and how often your plants need water is related to how crowded they are in their pots. Deciding when to repot is part science, part art. Yes, roots need adequate room to grow and spread but some plants are much more tolerant of cramped roots than others. Some indoor gardeners wait until their plants are half dead before repotting while others are over zealous and either repot too often or give their plant roots too much room. The most accurate answer to the question how often should I repot my houseplants? is actually whenever they need it. I realize it drives our callers crazy when they get an answer like this, but its true! The answer all depends on the needs of each individual plant and that will vary greatly. Talk to one of your friends who has a green thumb with houseplants. Chances are good he or she wont be able to give you definitive answers either, they just know. It takes a year or so of growing plants and observing them to get a feel for what makes them suffer and what makes them thrive. The best indoor gardeners are observant more than anything else. They can tell by the shine on the leaves or lack thereof if the plants are thirsty. They can tell by how the water seeps into the potting mix or beads up on top how dense is the root system. The only way to know for sure if a plant needs repotting is to look at its roots. This is relatively simple with plants in pots up to 10-12 inches in diameter. Just set it down over some newspaper, tip it upside down and tap the pot gently until the root ball slides out. Healthy plant roots are creamy white. Brown roots are often a sign of overwatering or extreme compaction. Large floor plants require two people to manage this job, and a lot of newspaper to catch the mess. Theres no exact number here, but if just a few healthy roots are visible around the outside of the rootball your plant is in good shape and doesnt need repotting. If the soil falls away its too soon to repot. But if all you see is a mass of roots and very little potting mix is visible, its time to repot. If you want your plant to grow bigger, move it to a pot just 1-2 inches wider than its current pot whenever the roots begin to fill out the root ball. To get maximum growth you want to avoid stunting the plant. A common mistake is to move a plant to a pot much bigger than it needs. You should choose a pot only two inches wider in diameter at the top when repotting. If you move to a pot too large the fresh potting mix with no roots tends to stay too wet and the plant almost seems to drown in all that soil. Gradual change in pot size is much better. If your plant is big enough and youd like to keep it from getting much bigger, repot less often and let the plant get a little cramped. When the roots become very dense, take a sharp knife and slice an inch off the sides and bottom of the rootball and replant it in the same pot with a fresh layer of potting mix along the sides and bottom. Water your plant well and keep it out of direct sun for a few days after doing this root pruning.