The fiery glow of  Sweetspire (Itea virginica ‘Henry’s Garnet’) seems to raise the temperate around it by a few degrees, although that’s purely an illusion today! The two main groups of pigments that give autumn leaves their colors are: Carotenoids, which produce yellow, orange, and brown colors; and Anthocyanins, water-soluble substances which are produced when there are high levels of sugars in leaves or fruits under bright light conditions. Bright days and longer cooler nights, with adequate, but not excessive rainfall, are generally considered to be the catalysts for great fall leaf color.

The U.S. Department of Agriculture has a good, readable explanation of “Why Leaves Change Color” online, for all of us who have never tired of asking “why?” Whatever the color, do heed the good advice on this site and others to rake and compost fallen leaves. They also make an excellent mulch when left in place where they fall. Tiny micro-organisms will put them to good use replenishing the all-important organic content of the soil.

Posted by Ann McCulloh

It’s All About Leaves This Month

Have you ever stopped to consider the wonder of leaves? In the spirit of the season, here are a few things you may not know. Leaves are solar panels…really efficient solar panels. Leaves come in unexpected forms. Did you know the spines on a cactus are really leaves? Did you know that the tendrils on a grape vine are really leaves? Did you know that all those little rose “leaves” on one little stalk are really part of one big leaf? Did you know that the celery stalks and onion bulbs you purchase are really leaves?

Leaves are extremely complex and not easy to describe. They come in so many different shapes and sizes, too. Botanists have a long list of separate descriptors for the overall shape of a leaf, the tip of the leaf, the edge of the leaf, the base of the leaf, etc.

See what I mean? There is no end to the wonder of green, but I must “leaf” off here.

Do you have any fun facts about leaves? Let me know.