Many house plants are sensitive to chemical fertilizers, showing their displeasure with brown leaf tips. Fertilize only during the growing season with a diluted soluble fertilizer. Once a month may be all that's necessary. The fluoride added to city water can also be overwhelming. Allow a full watering can to sit for 24 hours to help the fluoride dissipate.
House plants tend to dislike drafts and air pollution.
Don't place them near outside doors, fireplaces, or heating and air conditioning vents. Keep them dust free by wiping the leaves with a damp cloth. Raise the humidity by grouping plants together, placing them on beds of wet gravel and regular misting. Get rid of soft-bodied insects with a hard spray of water or horticultural oil. As your garden slumbers through the winter, now is the perfect time to turn your attention to the greenery inside your home.