Houseplant Care

Houseplants are killed or injured more often by improper watering than by anything else, and the second biggest limit is light. Everything else on this page, from soil to fertilizer, is about giving roots the right balance of water and air and the leaves enough light to use it.

Watering: check first, then soak

University of Wisconsin–Madison Extension puts most plants into two groups: those that like evenly moist soil and those that should be watered when the soil is dry to the touch. For the second, larger group the test is simple: push a finger about 1 inch into the mix and water only if it feels dry.

When you do water, water thoroughly. Pour until water runs out of the drainage hole, let it drain for 10 to 20 minutes and empty the saucer. A plant standing in a full saucer or a decorative pot without drainage stays waterlogged at the bottom, which is where root rot starts.

Iowa State University Extension phrases it well: check for water on a schedule, don't water on a schedule. If you are unsure, wait one more day.

Light: usually the real limit

Even the brightest windowsill gets a fraction of the light found outdoors, and light drops off quickly a few feet back from the glass. Most houseplants, even ones sold as low-light plants, grow best in bright, indirect light: bright enough to cast a clear shadow, without direct sun on the leaves.

Signs of too little light are slow growth, small pale leaves and long, stretched stems. Too much direct sun shows up as bleached or scorched patches. If your windows are limited, an LED grow light on a timer for 12 to 14 hours a day works well, especially from November to February; Iowa State's guide to supplemental lights covers how to size a setup. More plants for dim rooms are in our low-light plants collection.

Soil and pots

Use a bagged indoor potting mix, never garden soil, which compacts in a container. Succulents and cacti want a gritty cactus mix or regular mix cut with perlite; aroids such as monstera and philodendron like a chunkier blend with bark. Old, broken-down mix holds more water and suffocates roots, so refresh it every one to two years.

Every container needs a drainage hole. A decorative cachepot is fine as an outer sleeve as long as you lift the inner pot out to drain after watering.

Repotting

Repot in spring, when growth resumes, and only when the plant needs it: roots circling the bottom, growing out of the hole, or a root ball that dries out within a day or two. Choose a pot only 1 to 2 inches wider than the old one. Water the plant the day before, slide it out, loosen circling roots with your fingers and set it at the same depth as before.

Fertilizer

Potted plants have only the nutrients in their small volume of soil, so they need feeding, but far less than outdoor plants. Feed only during active growth, roughly March through September, with a balanced liquid fertilizer at half or a quarter of the label rate. Overfeeding causes lanky growth, brown leaf edges and a white crust on the soil or pot. If you see that crust, flush the pot with plain water until it runs freely from the hole.

Humidity and temperature

Most common houseplants are comfortable at 65 to 75°F during the day and a little cooler at night; keep them away from cold drafts, heating vents and radiators. Winter heating often drops indoor humidity well below 30 percent, which browns the leaf tips of ferns, calatheas and spider plants. A humidifier is the only method that raises room humidity meaningfully; grouping plants helps a little.

When something goes wrong

Yellow leaves, brown tips and drooping usually trace back to watering or light. Our problems section walks through symptoms one by one, and the pests section covers bugs on leaves and in the soil. Each plant in the A–Z catalog has its own care card with light, water, temperature and toxicity in one place.