Therese Teagarden, age 13, of Beech Grove, Indiana, for her question:

What is meant by a chemical garden?

The term chemical garden may refer to two very different things. One is a tank of living plants; the other is a container of non living crystals. The original is the living garden of organic chemicals. The non living cluster of inorganic chemicals merely reminded some poetic person of a colorful living garden. Some people call it a crystal garden. It forms, or grows, because when certain chemicals are dissolved they tend to settle and arrange themselves in lovely crystals. For example, copper acetate forms glassy blue green crystals, potassium ferricyanide forms red, and other chemicals form various rainbow colors.

The other chemical garden grows because plants use inorganic chemicals to build their living cells. Normally they absorb most of their raw materials from the soil. Chemical gardening became possible when we learned the basic diet that most plants need. This mixture of chemicals is dissolved in water and some plants can absorb what they need   without digging their roots into the soil. This sort of chemical gardening may be called hydroponics or soilless gardening.