Philodendrons love humidity so place them near a water source such as your bathroom or kitchen where steam will help increase the moisture in the air for them. They can also be soaked with water once a week, but make sure they are not overwatered or brown spots may form on their leaves. Fertilize every 2 weeks during active growth but reduce to once monthly in winter months when plants grow slower or become dormant. Avoid placing them near drafts, heaters, or vents that will dry out the air around the plants.