A Guide To Fall Plants And Colors

Autumn is my favorite time of year. I like it for the cooler temperatures, the fall harvests, Thanksgiving, my birthday and especially the fall colors. It goes without saying that fall is also my favorite time of year to be in the garden.

Since I was a kid, I have been in awe of the colors in autumn landscapes – the deep reds of oakleaf hydrangea, serviceberry’s show of oranges, the golden yellow of spicebush, and the carnival of color that is fothergilla – and the processes by which plants prepare themselves for the winter.

During the spring and summer months, trees and shrubs are actively producing chlorophyll so that photosynthesis can occur. As the days get shorter, chlorophyll breaks down and the plant no longer produces replacement molecules. The leaves change colors.

Plants contain pigments called carotenoids. Carotenoids are responsible for the yellows we see in plants in the fall. Though carotenoids are present in all plants, they are overshadowed during the growing season by the green of chlorophyll. Some plants also produce anthocyanins in response to bright light and excess plant sugars within leaf cells. Anthocyanins are responsible for the darker shades of red that certain plants exhibit in autumn.

Temperatures and rainfall leading up to, and during, the fall season impact the intensity of fall colors. Warm, sunny days and cold nights bring about the most impressive color displays. During the warm days, plants continue producing sugars, but the cool nights and the closing of veins in the leaves prevent the sugars from moving out to other parts of the plant. Sugar and light spur production of the anthocyanin pigments, which tint reds and purples. Because carotenoids are always present in leaves, the yellow and gold colors remain fairly constant from year to year.

Rainfall also affects the colors we see in autumn. That the weather is so unpredictable and variable, no two fall seasons can be the same. A late spring or drought conditions can delay the fall display. An exceptionally warm fall will result in less intense color. A warm wet spring, a fair summer, sunny autumn days and cool nights will result in the most spectacular show of fall colors.

As the summer of 2024 comes to an end, plants are stressed and gardeners are tired. The record heat and the inconsistent rainfall has impacted all of us. Though it is tempting to turn one’s back on their garden for fall festivals, football games and camping trips, I’d urge all of my gardening friends to keep on keepin’ on. Don’t give up now.

Plant your cool weather vegetables, and your cover crops. Plant bulbs and spring-blooming perennials. Amend the soil as you go. And water your plants – especially the newly planted ones. Fall is the ideal time to prepare your garden for the winter, and for the following growing season. Above all, I hope that you take the time in your garden to enjoy the fruits of your labor. Look around you and revel in the colors of fall!

Contact Barks Road Landscape Architecture, located at 1197 Baltimore Annapolis Boulevard in Arnold, for all your landscaping needs. You can reach Barks Road Landscape Architecture at 410-647-2090 or www.barksroad.com.