Arborist Josh Fritz covers the science behind why leaves change color in the fall, what it means if we see fall color too early, and fall tree care tips to keep your trees healthy and vibrant.
What Gives Leaves Their Fall Foliage?
The change in leaf color happens because of chemical processes that take place in the tree as the seasons change. (00:10:00)
These four pigments give leaves their fall color:
And the science behind it all….
During the summer chlorophyll gives leaves their green color. During the fall, chlorophyll levels dip and carotenoids become more visible which gives leaves their yellow color. Red leaves are due to anthocyanins. Orange leaves are created by both carotenoids and anthocyanins.
Tannins are typically found in oak trees and gives the leaves a dull brown color.
Continue reading below for more information:
This could be an indicator the tree is stressed.
Josh shows us an example of a Dogwood tree that’s been affected by a common tree fungus called anthracnose. (00:07:02)
When leaves have been compromised by a tree fungus, they cannot produce food so the tree will start to shed the leaves.
Water, fertilizer, and tree trimming (pruning)!
Drought stress is also a common issue for some regions during this time of year. To combat this, we recommend additional watering.
We provide a deep root treatment which is watering the tree and providing nutrients with fertilizer at the same time. (00:12:46)
The fertilizer replenishes nutrients lost during the summer.
Watering tip: you want to focus on the roots, not the leaves.
- Place an empty can by the area near the sprinkler
- Allow 1 inch of water to fill the can
That is how much water your tree needs a week.
Tree trimming (pruning) in fall also helps prepare the trees for winter dormancy, harsh weather conditions and storms, and promotes future growth. (00:23:38)
If you prune a tree during growing season, you are alerting insects and fungus and making your trees vulnerable to an infestation. (00:25:30)
Josh shares some of his favorite fall color trees (00:18:13):
- Sugar Maples
- Red Maples
- Black Tupelo (Black Gum)
- Japanese Stewartia
Upcoming Talking Trees Live Series
Tune in for the next Talking Trees Live event! We will explore various tree care topics from damaging tree insects and diseases to landscape best practices and seasonal tree care tips.
Be sure to have all your questions and concerns ready! You can ask them all live during the streaming interview.
Be sure to ‘like’ Davey’s Facebook page to access the Talking Trees series live.
Don’t have Facebook? No worries, you can access all the past videos here.