The Effects of a Greenhouse

Materials Needed:
Rectangular cake pan
Grass seed
Potting soil
Clear plastic cup
Spray bottle
Water

What to Do:
Pour potting soil into the pan.
Plant some grass seed on top of the soil.
Using the spray bottle, water the soil lightly.
Place the plastic cup upside down on top of the soil.
Place the pan in sunlight.
Water the soil as necessary.
Challenge the children to guess if the grass will grow under the cup, and if so will it grow faster or slower than the rest of the grass in the pan.