A houseplant is any plant that can be grown in an ordinary room. Houseplants can be hardy or tender but well-adapted to withstand average house conditions—dry atmosphere, warm and sometimes uneven temperatures, and often inadequate light.
The best spot for a houseplant is a room that gets sunlight, and the best position is nearest the window, but there are a few houseplants that can grow in low light.
Houseplants do best in a pot that is well-drained set in a saucer that permits excess water to seep from the pot into the saucer rather than lying about the roots of the plant. As moisture evaporates from the saucer it helps create a moist atmosphere that most plants need.
Here are four things houseplants need to grow and thrive:
Enough water. Houseplants usually need watering once a week. They need just enough water to wet the soil and seep a bit through the bottom drainage hole.
Enough light. Light is needed for plants to metabolize water and nutrients. Bright to medium light is what most houseplants need; this is sunlight that comes through a window to several feet into a room. Houseplants need 12 to 16 hours of light and 8 to 12 hours of dark each day.
Enough heat and humidity. The optimal temperature for most houseplants is 60 to 75°F (16 to 24°C) during the day and a temperature drop at night of 5 to 10°F (3 to 6°C)—lower temperatures and darkness at night allow houseplants to rest. Related to temperature is humidity. Houseplants are almost always tropical in origin; in addition to warmth, they want humid air—not dry air that flows from a heater or air-conditioning vent.
Enough nutrients. Houseplants need nutrients but not a lot. They especially need feeding during their active growing and flowering season. At three- or four-week intervals they should receive liquid food, a complete fertilizer meaning a near even dose of nitrogen, phosphorous, and potassium—10-10-10 for foliage plants, 10-15-10 for flowering plants.
How to purchase a houseplant
Decide where the plant will grow. Decide if you want a flowering plant or a foliage plant. If you need more than one plant make a list of the number of flowering and foliage plants needed. Determine the size plant needed for each spot.
Estimate the amount of light where the plant will grow. Is the spot bright, muted, or dark? Flowering plants require more light than foliage plants. If the spot for the plant is away from the window, you will need a plant that can tolerate low light.
Shop where houseplants are featured. Shop at a garden center or nursery that makes houseplants a specialty, where there is a wide selection, and where sale associates can offer advice.
Examine the plant carefully; does it look healthy? Is the color good? Does it have a pleasing shape? Is there new growth? Are the leaves free of damage and pests? Look over the selection of plants; if all of the plants look healthy that is a good sign they have been cared for. If some look wilted or stressed, exercise caution when you select your plant.
Is the plant potbound? Are roots growing through the drainage hole or over the edge of the pot? Choose a plant that is not potbound.
Choose the size plant you want. If you need a large plant for the spot you have in mind, then select a large plant—and spend a little more money. Waiting for a plant to grow to the size you want can take months, even years.
Stephen Albert is a horticulturist, master gardener, and certified nurseryman who has taught at the University of California for more than 25 years. He holds graduate degrees from the University of California and the University of Iowa. His books include Vegetable Garden Grower’s Guide, Vegetable Garden Almanac & Planner, Tomato Grower’s Answer Book, and Kitchen Garden Grower’s Guide. His Vegetable Garden Grower’s Masterclass is available online. Harvesttotable.com has more than 10 million visitors each year.