Knowing when and how often to feed your plants can be terribly confusing.  Generally, most plants should be fertilized in spring and summer when they are putting out new growth or blooms.  At the same time, most need to rest over the winter months and shouldn't be fed.

Certain plants grow throughout the year and should be fed lightly year round.  They usually prefer to be fed smaller doses each time than other plants.

There are many kinds of plant food available, from time-release capsules to liquids and powders.  Any balanced fertilizer specifically designed for houseplants is fine.  On the label you'll see a set of numbers, such as 10-20-10 or 12-6-6, describing the blend of nitrogen, phosphorus, and potassium (or potash) in the fertilizer.  Nitrogen gives the plant lush foliage, and phosphorus keeps roots and stems strong and healthy.  Potash encourages more colorful blooms.

Follow the directions on the container for proper dosage and frequency, or establish your own feeding schedule based on what your individual plants need.  Make sure the soil is sufficiently moist before applying fertilizer.  Applied to a dry soil, fertilizer can burn roots and stems.  Remember, too much fertilizer can produce weak stems and leaves.  Hold up feeding of new or repotted plants for eight weeks until they've had time to adjust to their move.

If you prefer organic fertilizers, fish emulsion or bone meal will give good results.