Houseplants need lots of humidity for good growth. So in the winter, when the heat is on and the air is dry, mist-spray your leafy plants at least every other day early in the morning. Use weak tea water, which you can make by soaking a used tea bag and 1 teaspoon of dishwashing liquid ( Anytime a recipe calls for dishwashing liquid, DO NOT USE detergent or any product that contains antibacterial agents) in a gallon of warm water until the mix is light brown. Follow this schedule in summer, too, if your home dries out because of air conditioning.