Help plants to settle in their new homes

When houseplants don't grow well, or they start to look sick, it may be time to give them a new home.

A houseplant's home is its pot. The plants may have outgrown that pot, which means it's time to leave the starter home and move to a larger abode.

"Houseplants eventually get root-bound, when the pot is so full of roots that plants have no more space in which to grow," writes author and gardening columnist Julie Bawden-Davis. Also, salts can build up, and that can harm plant health.

Now through summer, as houseplants actively grow, is a good time to repot them, says Ms. Bawden-Davis in her new book, Indoor Gardening the Organic Way (Taylor Trade Publishing, $19.95).

And though talking your plants through the move to their new home, as the author admits doing, is not standard gardening practice, the book has great ideas and techniques for repotting houseplants, whether you are an organic gardener or not.

She recommends repotting when you see one or more of the following:

•Roots coming out the bottom of the pot, or a mass of tangled roots in the pot.

•Constant thirst and soil that dries out quickly.

•Water rushing through the pot when watering.

•Sluggish growth.

•Top-heaviness, which indicates the plant has outgrown the pot.

•Staining on the soil surface, indicating salt buildup.