Pineapples (Ananas comosus) are tropical plants, belonging to the bromeliad family. These fruiting perennials do well outdoors in U.S. Department of Agriculture plant hardiness zones 10 through 11 but are sometimes grown as houseplants. Pineapples do well when grown in containers and are easier to grow indoors where they are protected from insect pests and cool weather. Most grow these plants for their spiky foliage and tropical feel rather than for fruit— it can take two to three years for the plant to produce fruit.
Purchase a pineapple plant at your local nursery. If you have trouble finding a suitable young plant, simply purchase a fresh pineapple with plenty of green leaves at the grocery store. Cut the crown off the pineapple as close to the leaves as possible. Remove all of the fruit from the crown until only the leaves remain. Cut off thin slices from the bottom of the crown until you see a row of brown dots—these are young roots. Let the pineapple top-dry for a day or two before planting.
Choose a suitable planting location for your pineapple plant or top. Pineapples need sandy or loamy soil that drains well and prefer their soil slightly acidic. If you are planting your pineapple in a pot, choose a 3- to 7-gallon container and use cactus soil. Pineapples also like full sun but will do well in very light shade. For optimal growth and fastest fruiting, choose a location where the temperature will stay between 68 and 80 degrees Fahrenheit.
To plant a nursery specimen, dig a hole twice as deep and three times as wide as the container. Loosening this much soil will make it easy for the pineapple's roots to spread. If you are planting a pineapple crown, simply plant it about an inch deep, removing any leaves that would be covered by the soil. Backfill your planting hole and water the plant thoroughly.
Water your pineapple plant no more than once a week if rainfall hasn't done the job for you. Pineapples like moist soil but do not tolerate flooding or wet feet. Always check the soil moisture before assuming your plant needs a drink. When in doubt, skip the water.
Pineapples have small root systems, so they absorb most nutrients through their leaves. When you start to see new leaves, fertilize your plant with a foliar spray every 8 to 10 weeks. You can use a citrus fertilizer, or choose a fertilizer with an NPK ratio between 6-6-6 and 10-10-10 and which also includes 5 to 6 percent magnesium. If your plant hasn't flowered in 16 months, take a break from fertilizing over the winter to induce flowering and subsequent fruiting.
Pests are not usually a problem indoors but they can plague garden-grown pineapples. Inspect your plants frequently for mealy bugs and scale insects. Look for ants, as well, as they sometimes herd mealybugs onto plants to farm them. A shot of water from the garden hose is enough to dislodge these insect pests. If the pests persist, treat the plant with insecticidal soap on a cloudy day. Chemical insecticides can be applied as a last resort, but do so carefully if you intend to eat the fruit your plant produces.
Stake your pineapple if the growing fruit becomes top heavy. If there is a fear that possums, raccoons or other critters may dine on your pineapple before you can harvest, place a paper bag over the growing fruit to keep animals at bay.
Harvest your pineapple when the fruit shell changes from light green to a greenish yellow. Finish ripening the fruit at room temperature on your counter. The pineapple is fully ripened when it turns yellow.