Science Behind Fall Color + Autumn Leaf Fall
It’s that time of year again, when brilliant autumn leaves are contrasted against the dark blue sky for Nature’s annual riot of color before somber winter. As the green chlorophyll in summer leaves decreases, other leaf pigments take over.
Chlorophyll is replaced by orange carotene, yellow xanthophyll, and red, purple and magenta anthocyanin, using the same chemistry as the colorful antioxidants so important in the fruits and vegetables we eat (carrots, blueberries).
What happens next? - Falling Leaves
While the leaves are changing color, a corky abscission layer between the twig and the base of the leaf-stem (petiole) begins to interrupt the upward flow of water and minerals from tree roots, and the leaf eventually dries out and falls to the ground. Just as different types of trees turn different colors (red maple, purple-red black gum, yellow Japanese maple), the amount of time that leaves persist on the trees also varies. The U.S.D.A. provides areally thorough discussion of fall foliage.
|American Beech Fall Leaves|
Because the beautiful leaf colors fade like tissue paper left out in the sun, leaves that persist through the winter on some trees turn brown. Russet oak leaves, brown hickory leaves or beautiful cinnamon-tan American Beech leaves rustle in the forest throughout the winter.
What does this mean to Residents, HOA Reps and Property Managers?
Because of this variability, leaf drop is an ongoing process lasting from November through late February or March. For example, the Pin Oaks retain fall leaves until new leaf buds push them off in early spring. Since leaves do not drop at once, it is unrealistic to think that they can be cleaned up once and for all.
|Old Man Wind|
Wind is Another Factor
Consider the strong winds in metro-Atlanta from Hurricane Sandy last week. For example, if your Crabapple Team is scheduled to arrive in your ‘hood and the wind is gusting that day, spotless areas that we completely clean up may become covered with leaves blown in from another location minutes after we depart. This is the nature of Nature.
Every Property is Unique
Some properties have natural areas where the LandscapExperts can blow the leaves. Leaves will be trapped by trees and shrubs growing in the natural area and will decompose naturally over the course of the year.
Other customers prefer that all the leaves are cleaned up and removed from the property. Due to differences in leaf drop on trees, this will be an ongoing effort from November through early March.
Did you know? Falling leaves are filled with nutrients taken up from the soil and accumulated during summer growth. Imagine an untouched forest ecosystem with a rich woodland soil. Vitamins, minerals and elaborated carbohydrates like sugars and starches in the leaves are returned to enrich the soil. When they fall to earth they are decomposed by earthworms, protozoa, arthropods, friendly fungi and beneficial bacteria naturally present in every soil in the world.
While other companies might haul this waste to a landfill, your Crabapple LandscapExperts have a recycling program in place that demonstrates our 20-year commitment to the Environment.
|Crabapple's Earth Stewardship: Green Recycling|
Even when leaves are entirely removed from a property, the soil is not depleted because of Crabapple’s careful stewardship. We remove your leaves as desired and take them back to our HQ where they are composted in a massive compost pile turned by heavy equipment. Crabapple recycles more than 2,000 cubic yards of vegetative matter each year. This includes leaves, branches, weeds, brush and so forth that are shredded and added to the pile. Rich compost is returned to the properties we care for in the form of organic mulch that we use to top dress shrub beds and enrich annual color beds.
Ask your Crabapple Rep if you would like more information about on the annual autumn leaf drop in the community you manage.
Old Man Wind cartoon courtesy David Laufer