How do you know when a plant needs to be repotted?

A rootbound plant in a pot that's too small is a prime candidate for repotting. How can you tell? There are three symptoms to look for:

• Water runs out of the drainage hole too quickly. This means that the soil in the pot has become replaced by roots!
• The roots are growing out of the drainage hole.
• The entire plant is top-heavy. A good rule of thumb is that your container should a diameter of one-half to one-third the height of the plant.

When repotting, line a table with newspaper for easy cleanup, and arrange your materials so you can work quickly. Plants can go into shock once you've removed them from the soil, so make the transition a speedy one for best results.