Weâ€™re falling for autumn.
Itâ€™s August, which can only mean one thing: Fall is just weeks away. Here, we look at what makes this such a colorful time of year and list a few of our favorite indications that autumn has arrived.
The splendor of autumn
Each year, starting around September in most parts of the country, fall colors arrive in all their glory. The vivid greens of summer are replaced with a mixture of bright red, yellow, and orange. This stationary change of scenery is the result of a seasonal chemical process.
In the growing season, spring and summer, leaves serve as a factory that produces the food and energy necessary for a tree to grow. This food-making process is fueled by cells that contain chlorophyll â€“ the chemical that gives leaves their signature green hue. Chlorophyll is activated by the sun and works to transform water and carbon dioxide into carbohydrates (in starches and sugars) that provide vital nutrients to growing trees.
Interestingly, leaves also contain high levels of other pigments, including xanthophyll and carotene. However, the orange and yellow tones provided by these are masked most of the year until fall.
Chlorophyll breaks down
In the fall, days become shorter, nights longer, and a chill permeates the air. This atmospheric change signal leaves to stop making food. The chlorophyll contained inside the leaves breaks down, allowing orange and yellow colors to become dominant. Other chemical changes may occur during this time, triggering the development of anthocyanin pigments, which manifest as visible shades of red. Waning levels of chlorophyll and increased levels of other chemicals also give rise to deep purple and orange leaves.
In the autumn, most foliage is displayed as beautiful canopies of yellow. However, oak and many other trees have leaves that fade to mostly brown. The diverse mix of colors throughout the fall results from varying amounts of residual chlorophyll.
Fall not only heralds a change of color. Leaf stems, too, are transforming. When the tree and stem meet, a layer of special cells develops, which later severs their connection. As leaves begin to blanket the ground, tiny scars remain on the tree, allowing new growth the following spring.
In North America, most broad-leaf trees shed their leaves in autumn. Oaks and other species, however, typically maintain their color until the new season begins. In the South, many broad-leafed trees do not change color as mild winters permit year-round growth.
The evergreen effect
Not all leaves change colors. Some conifers, including fir, spruce, pine, cedar, and hemlock, keep their bright green hue year-round. These are called evergreens and are exemplified by needle-like leaves that may stay attached to the tree for several years.
Whether and color intensity
Yearly temperature fluctuations affect the color intensity of leaves. An unseasonably cool fall, for instance, will encourage anthocyanin production in maples, rendering a bright red landscape. Likewise, warmer weather will allow the trees and forest to maintain their green coloring longer.
Fall is a season that seems to bring people together. Pumpkins are everywhere, and there is a crispness to the air that invites an exciting combination of seasonal activities.
The fall, according to many, signals the beginning of the most critical time of year: football season.
The sights are not the only familiar sensation ushered in by fall. The scent of pumpkin, vanilla, and various spices are abundant.
Cool-weather means an update to your homeâ€™s in- and exteriors. Fall dÃ©cor consists of vines, gourds, hay bales, and corn stalks. In October, jack-oâ€™-lanterns smile from front porches across the country.
Fall is when many seasonal allergy sufferers either emerge from their summer havens or retreat into hibernation. The cooler air thwarts the growth of some allergens while breeding others. Many consider the cool crisp air of autumn Mother Natureâ€™s way of rewarding people for surviving the crippling heat of summer.
Thoughts of fall send shivers of excitement down the spines of children from California to Maine and everywhere in between. Itâ€™s a signal that holidays are fast approaching. Many families have unique traditions in the fall, such as pumpkin patch excursions, Halloween shenanigans, or fireside snuggles.
In the kitchen
Who can deny the exceptional scent of fresh pumpkin bread or apple pie wafting through the air?
Across the US, fall is the beginning of the festival season. Here in Tennessee, we revel in fall in a big way. Erwin, TN, is the home of the Annual Unicoi Apple Festival. In Helen, Georgia, they enjoy a month-long celebration starting the first week of October. The Helen Oktoberfest is one of the nationâ€™s longest-running events; 2015 is its 45th year.
Tennessee Wholesale Nurseries provides a plethora of perennials perfect for your fall flower garden. Feel free to contact us for more information or allow one of our experienced tree, shrub, and flower experts to help you choose which fall-friendly foliage is suitable.