Check the plant and pot for any crusty white buildup. Salts accumulate in containers without drainage holes.
Repot the plant in a pot with drainage holes. Add holes to a plastic container by removing the plant, drilling a few 1/8-inch holes in the bottom of the cotainer and repotting the plant. The number of holes depends on the size of the container; between five and 10 is usually adequate.
Lift the pot and look for roots growing out the bottom. If you see them, the plant is wilting because the container is too small and can't hold enough water.
Repot the plant in a larger container. A new container should be large enough to fit the entire root ball with a few inches of growing room on all sides.
Inspect the plant for insect damage like deformed or curled leaves, small white or silver speckles, or deformed and discolored flowers.
Check for insects if you see signs of damage. Aphids are soft bodied, pear-shaped insects that can be green, pink, yellow, orange or black. Mealybugs are slow-moving with a cottony, white coating. Scales look like brown, circular scabs. Thrips are difficult to see but cause silver spotting on leaves with black excrement speckles. Spider mites are also hard to see but leave fine webbing all over leaves, buds and flowers.
Wipe aphids, mealybugs and scales off the plant with a cotton ball dipped in rubbing alcohol. Spray spider mites and thrips with insecticidal soap. Prune out any heavily infected leaves and stems to improve the plant's appearance.
Stick your finger in the soil down to the second knuckle to see if it is dry.
Water the plant thoroughly if the soil is dry. The soil should be moist throughout the pot.
Discard any water left in the drainage dish 15 minutes after you've watered.
Depress the soil with your finger to check for moisture. If the soil is wet and the plant is wilting, too much water sitting in the pot may have caused the roots to rot.
Remove the plant from its pot and check the roots for soggy, brown spots. If the entire root system is brown and mushy, discard the plant; you can't save it. If only a few roots are brown, trim them out just above the brown spots.
Sterilize the old pot with a cleaning solution of one part bleach to nine parts water or use a new one.
Repot the plant in fresh potting soil. Ensure proper drainage with drainage holes, and only water the plant when the top two inches of soil are dry.
Check for cold drafts from air-conditioning in the summer or from windows or doors in the winter. Some tropical plants will wilt suddenly and may even lose their leaves if exposed to a draft.
Move the plant to a warmer spot away from vents, doors or drafty windows.
Check for hot spots from morning or afternoon sun, heating vents or radiators. Plants that are sensitive to heat may wilt if exposed to high temperatures.
Move the plant to a cooler spot, avoiding heating vents and direct sun.