With a small-scale pineapple fruit no larger than a tennis ball, the miniature pineapple (Ananas nanus) grows more as an ornamental oddity rather than a bountiful fruit crop. It's native to Suriname and northern Brazil and falters when temperatures drop below 60 degrees Fahrenheit. Maturing to about 18 inches tall and 24 inches wide, grow it in a container to bring it indoors to overwinter as a house plant. Grow it as an outdoor garden plant only in USDA Hardiness Zones 10 and warmer.
The miniature pineapple needs as much direct sunlight as possible, whether grown outdoors or as a house plant. More than 6 hours of sunlight daily helps warm the soil, as well as keep foliage firm and well-shaped. Too little light causes leggy or thin leaves, overly green coloration, and likely reduces the chances for production of a flower stalk and subsequent fruit.
While many bromeliads are epiphytes, growing out of soil and clasping to other plants, the miniature pineapple grows in soil. Grow it in a well-draining fertile soil that is rich in humus. Sand-based soils with compost and mulch create good growing conditions if they stay evenly moist during the warmth of the growing season. Avoid heavy clay soils or those that remain soggy after rain or irrigation watering.
Water the miniature bromeliad freely during the growing season and when the flowering stalk is present. The soil should remain moist from spring to autumn. Pouring the water over the entire plant allows water to run into leaf gaps and crevices and drain away to the soil below. In winter, reduce watering so that the soil remains barely moist and dries out between watering. Since the soil is fertile and contains organic matter, do not worry about fertilizing the pineapple. In fact, too much fertilizer causes fast growth and often limits the plant's ability to create a flower stalk. Fertilizers containing copper nutrients are generally fatal.
When the miniature pineapple reaches a mature age, the center of the rosette of spiny leaves produces a flower stalk. The stalk elongates and rises above the foliage to reveal a rounded cluster of lilac to red flowers with yellow bracts, resembling a pine cone. After the flowers, the ovaries swell into plump, pulpy masses to create a small pineapple fruit with a large crown of foliage. The flower stalk may remain fully erect or eventually bends over to allow the mature fruit to drop to the soil below, where it will root and become a new plant. Consider staking the stalk to keep the plant looking more ornate and keep watering it during this time, so that the flower and fruits do not abort prematurely.
Once the plant fruits, it is destined to die. While the top of the small fruit grows into a new plant when it reaches the soil, the mother bromeliad also develops small new plants called pups at her base. The mother plant will slowly decline over one to three months, allowing the pups to increase in size. Once the mother plant looks too tattered or brown, cut it off with a pruners at its base. Use gloves to protect yourself from the leaf spines. Take care when cutting so you do no remove or damage the one to three young pup plants emerging from the mother plant's base. With the mother plant removed, the pups gain more light, air and resources from the roots to grow more quickly. Within a year, these pup plants grow to a large size, often ready to flower and fruit, and continue the process if conditions are right.