A Plant with Its Own Water Tank

Experiment with a pineapple to see how a bromeliad catches water and animal and plant litter.

A bromeliad is a tropical plant in the pineapple family (the family Bromeliaceae). Some bromeliads are brightly-colored epiphytes, which live on the branches and trunks of rainforest trees. They have a remarkable way of getting water and food. Their long, curved leaves overlap at the base, forming a tight little bowl -- a perfect water tank! The leaves act as gutters to collect rain, and the tank holds the water. The largest bromeliads hold up to two gallons of water.

Many animals drink from the bromeliad water tanks. And many others actually live in the water held by bromeliads. Scientists have found more than 250 different animal species in the tanks of bromeliads, including frogs and tadpoles, insects and insect larvae, spiders, and worms.

The animals that live in bromeliads bring nutrients to the plant in their droppings and when they die. The spiky leaves of bromeliads trap forest litter, too. Bromeliads can absorb nutrients through special leaf pores, which other plants don't have.

Play with a Pineapple

Experiment with a pineapple to see how a bromeliad catches water and animal and plant litter.

What you will need:

  • A fresh pineapple from the supermarket
  • A sharp knife (to be used with adult supervision)
  • A trowel or large spoon
  • Soil
  • A container to grow the pineapple in water

What to do:

  1. Choose a pineapple with healthy green leaves. Cut off the top of the pineapple, leaving about 3 inches of fruit attached to the leaves.
  2. Let the pineapple top dry for a day or two. Then remove the soft fruit, but leave the core attached to the leaves.
  3. Fill a container with soil. Plant the pineapple top with the core in the soil and the leaves above the soil. Water the pineapple plant.
  4. Set the pineapple in a sunny place. Water it when the soil gets dry.

Try This!

After your pineapple plant has grown some new green leaves in its center, put the plant outside during warm weather. Place the plant in its container under some shrubs or trees, and leave it for several weeks. (Don't forget to water it if there is not enough rain.)

Check the pineapple plant everyday or so to see what is collecting in its center. After a rain, is there water in the center of the plant or at the base of the leaves? Look for particles of dirt, leaves, pine needles, or flower petals. Are there any insects or worms on the plant?

Of course, a bromeliad has a wider, deeper center than a pineapple does, but you should get some idea of how the bromeliad works.

Pineapples growing in a field

Pineapples growing in a field.

Photo credit: iStock

Reprinted from The Remarkable Rainforest by Toni Albert, copyright © 1994 by Toni Albert. By permission of Trickle Creek Books. If you order this book directly from the publishers at 800-353-2791, mention the Rainforest Alliance. Then 30 percent of the retail price ($10.95) will be donated to the Rainforest Alliance.


Forest canopy - photo by Sergio Izquierdo

Support Our Work

Create a world where people and the planet prosper together.