I love to buy pineapples cut off the tops, put into (on top of) water and get roots to grow and then plant them. Getting roots is almost always successful as is getting them into the ground. But of all the pineapples I have grown, and they have grown pretty big, only one has produced fruit. Can you help? How do pineapples reproduce? Once a pineapple produces fruit do you just leave it as is and it will give more fruit or do you have to cut it down?
As you've already discovered, pineapples make an attractive, fun addition to the home garden.
You seem to have a system for starting pineapples that works great for you. Other gardeners have found the following method also works. Simply cut off the leafy top or crown of a fresh pineapple about 1/2" below the base of the leaves. Remove any soft flesh leaving only the tough, stringy core attached to the leaves. Strip off the lower leaves exposing 3/4-1" of the stem. Next, place the top in a dry, shaded location for several days before planting. This will allow the tissue to dry out and seal and discourage rot.
Once ready to plant, place your stem in a well-drained potting mix. The base of the stem (including the crown of the fruit) should be covered with soil. Tamp the soil around the base of the crown. Water and continue to keep the soil moist, but not wet. Pineapples do not tolerate wet soils. Place your pineapple in bright, indirect light. Rooting should occur in 6-8 weeks. It can then be moved to a sunny window. Fertilize your plant once a month with a soluble houseplant fertilizer.
Pineapple plants take about 2-3 years to mature and begin flowering. After flowering, the developing fruit can take another 6 months to mature. Flower development in Hawaii usually occurs in the shorter and cooler days of December and January. For those of us growing pineapples indoors we need to have slightly different expectations and provide a bit different care. Once the plant is pot bound it often acts like a mature plant. Place several slices of a ripe apple in a plastic bag with your plant. The apple emits ethylene gas that stimulates flowering. Close the bag and keep the bagged plant out of direct sunlight for 3 to 7 days. Remove the plant from the bag, return to the sunny window and wait. Your plant should flower and eventually form a small pineapple.
Once the fruit has ripened, the original plant eventually dies. But don’t worry one or more shoots develop. You can divide and repot these shoots and start the flowering and fruiting process over again.