Spring is a good time to repot houseplants, if they're overcrowded or looking tired.

Here's how:

• Carefully turn the pots on their sides and slide the root ball out. With plants that have been in the same pot for a while, you may need to run a knife around the inside of the pot to detach the root ball.

• Look for roots that are firm and healthy. If you see black, slimy or rotted roots, snip them off. Loosen the roots or, if they've grown in a circle in the pot, run a knife or scissors down the outside of the mass and remove the excess, leaving a clump of healthy roots.

• Most plants should be repotted in containers that are only an inch or two larger in diameter than the one they were in. Pots with drain holes are best. Cover the hole with a shard of broken pot, a coffee filter or some newspaper and add a couple inches of fresh potting soil.

• Position your plant in the pot and gradually fill in soil around it, gently shaking the pot and tamping down soil to help the plant settle. The plant should be planted at the same level it was in the old pot. Once you're done, water well.

• Don't fertilize newly potted houseplants. If you do, you run the risk of burning plants that already are facing the challenge of adjusting to their new homes. Give them a couple of months to ease into their new containers, then begin to fertilize.

Mary Jane Smetanka