Charles Anderson, age 10, of Staten Island, N.Y., for his question:

WHAT MAKES IVY STICK TO BUILDINGS?

Ivy is a favorite landscaping ground cover. The name covers a large variety of creeping and climbing vines. Common ivy, or English ivy as it is also called, climbs    over walls and up buildings and trees. It has waxy, five pointed leaves that are dark green in the summer and turn scarlet in the fall. Ivy's secret for being able to cling to a smooth surface its stems are covered with fine air roots that have the ability to grab and hold.

You'll find Boston ivy, which is also called Japanese, climbing the shady sides of buildings in the Eastern parts of the United States. The three pointed leaves overlap each other as they cover a wall. The plant is related closely to the Virginia creeper.