A population explosion in a pot, the spider -- or airplane -- plant (Chlorophytum comosum) was made for hanging baskets. Perennial in U.S. Department of Agriculture plant hardiness zones 9 through 11, it's a delightful indoor accent elsewhere. In the right growing conditions, arching stalks sprout from the ends of its long, narrow leaves. Each is an umbilical cord attached to a miniature plantlet. The effect is that of a fountain spawning dozens of smaller ones -- unless brown ends on the leaves spoil its flow. Any of several easily corrected problems could be at fault.
Hard water may be the most common cause of brown ends on spider plants. It's loaded with root-damaging, leaf-browning mineral salts. Water softener contains the same salts, so using it won't help.
One misconception is that fluoridated or chlorinated water browns spider plant leaves. Unless it's in water straight from a heavily chlorinated swimming pool, chlorine evaporates too quickly to be a problem. Fluoride in municipal water is too diluted to harm all but the most sensitive plants. Letting tap water sit overnight only concentrates its fluoride as the water evaporates.
To avoid water-associated leaf browning, use only room-temperature, filtered, distilled or rainwater. Even they, however, won't stop leaf browning if the potting soil becomes parched. Whenever the top 1 inch of soil feels dry, water thoroughly. During the spring-to-fall growing season, this may be twice or three times weekly. During winter, once weekly is usually sufficient.
Excessive fertilizing also causes salt-related leaf browning. From early spring to late summer, fertilize your spider plant every two weeks with half-strength, water-soluble 20-20-20 fertilizer.
Dissolve 1/4 teaspoon, or one-half the label's recommended amount, of the fertilizer granules in 1 gallon of room-temperature, filtered, distilled or rainwater. Moisten the potting soil and pour the fertilizer solution evenly over its surface.
In fall and winter, reduce the fertilizer applications to once a month.
Leaching Salty Potting Soil
To minimize fertilizer damage, leach built-up salts from the potting soil. If a whitish crust coats the pot's inside rim or the soil's surface, it's time to leach.
Saturate the potting soil with room-temperature, distilled, filtered or rainwater until liquid flows from the pot's drainage holes. Let it drain for 30 minutes and repeat. After it drains again, pour off the water and empty its drainage tray. Don't water or fertilize again until the top 1 inch of potting soil feels dry to the touch.
Sun and Temperature Damage
Brown ends are common on spider plants in direct sun or hot, dry drafts. Give your indoor spider plant moderate light 5 feet to 8 feet from a sunny window, where sunlight won't land directly on the leaves. Keep it away from heat registers, at daytime temperatures between 65 and 75 degrees Fahrenheit dropping to between 50 and 55 F at night.
If looking at the leaves' brown ends is just too unpleasant, snip them off with a pair of sharp scissors disinfected in rubbing alcohol before and after you work. For a natural effect, taper the new leaf ends with a disinfected razor blade. Cut just inside the edge of the brown area; if you damage the green tissue, a new brown margin will result.