Knowing how vibrant the fall colors will be each year is more of an art than a science. It's kind of refreshing that a few annual events cannot be precisely predicted. Maybe eventually we'll all know the date when that Sugar Maple down the street will be a brillant crimson color, but right now, the answer is largely guess work.

What ingredient is missing from the following list that is required to produce vivid fall colors (sunny days ,cool nights, adequate soil moisture, near normal temperatures)? The simplified answer is reduced amounts of daylight or shorter days. When less daylight is available the ability of plants to produce chlorphyll to support photosynthesis is reduced. When this happens (in October for most places in the U.S.), other pigments that are always present in deciduous leaves, such as anthocyanins (red) and carotenoids (orange and yellow) become much easier to see. Other factors that can affect the hues of the fall colors are damage to the leaves by insects and whether or not severe storms injured the trees. In general, healthy trees produce the brightest colors.

Sunny days, cool nights, adequate moisture in the soil, and near normal temperatures are required to produce vivid fall colors. Name an ingredient (or ingredients) that is missing from the above list.

10/25/95