Pineapples are American tropical plants that contain large fruit with thick, edible flesh covered by a hard, scaly outer skin. The pineapple fruit is an excellent source of vitamins and nutrients, and can also serve decorative purposes. Due to the pineapple's popularity around the world, it's widely cultivated. While pineapple seedlings can take almost two years to bear fruit, with the proper planting and care, you can grow pineapples from seeds.
Cut a ripe and healthy pineapple into 1/2-inch slices. You can tell a pineapple is ripe when it has a bright, yellow-gold color, especially around the base. As you cut the pineapple into slices, you'll see small, black seeds in the fruit's flesh. Separate the seeds from the flesh, wash them with water, then let them dry on a baking sheet or towel.
Place the seeds into a glass container, cover it with a lid and put the container into a warm place that does not receive direct sunlight.
Wait several weeks while the seeds begin to germinate. You'll know they're germinating when you begin to see small, white and green roots sprouting out of the seeds. Wait until the roots have sprouted 1 inch from the seeds before planting.
Fill small, transparent planters with soil. Use tweezers to remove the seedlings from the jar and plant them into the soil, several centimeters apart from each other. Bury the seeds under the soil with the sprouts above the soil. Cover the planter with a transparent, dome-like cover.
Water the planters approximately once a week, so the soil is moist but not flooded. The exact watering schedule may vary slightly, depending on the conditions of your indoor room and your location. Always check the soil with your fingers before watering. If it's dry to the touch, then you need to water. If the soil feels moist or muddy, wait another day or two before watering again.
Keep the seedlings in the covered planters for another few weeks, in the same place where you kept the germination jars, until they double their size and begin crowd the planter.
Transplant the seedlings into individual, 1- to 3-gallon containers once they begin to get crowded. The new, larger planters do not need to be covered. These individual containers will be large enough to sustain the full growth of the pineapple plants until the fruit is ready to be harvested.
Fertilize the seedlings lightly once a month with a balanced liquid fertilizer, such as a 6-6-6.
Continue watering and fertilizing for the entire life of your pineapple plant, or until you decide to harvest the fruit. The plant should bear fruit after 20 months, but it can take up to three years.