There is then a buildup of sugars, which in turn, triggers the breakdown of chlorophyll. As the chlorophyll begins to beak down, the natural colors, or pigments are allowed through. The type of growing season we have, available moisture and gradual temperature changes, all play a part in how pretty our fall foliage is. Some years killer drought gives us a fairly quick fall, since many trees shed their leaves early. In years with ample rains we have a pretty fall.
Frosts play no part in fall colors.
In fact, it actually damages the compounds that produce the fall colors, encouraging leaf shed. Cool night time temperatures, especially in the 40's and 50's, do help with fall color. Plant in Fall Different trees contain different pigments. To be sure of fall color, you may want to choose a tree in the fall. And fall, is an ideal time to plant.