Someone else go out in the morning and scratch their head to find out where all the leaves are coming from? Has anyone else spent the past weekend raking leaves, feeling like you had to get the garden tools out a little earlier than last year?
Just two weeks into the onset of fall and almost a month before the city of Indianapolis usually begins its fall leaf collection, central Indiana is seeing leaves falling all over the place. While Hoosiers eagerly wait for the fall colors of red, orange and yellow to take over the canopy, the only hues many see are shades of dull green and brown. On the ground.
That said, the question that worries many people becomes: am I going crazy or are the leaves falling early – and, if so, why?
We spoke to a few tree experts to understand what is going on and what, if anything, residents should know about how to fix it. So read on to get to the bottom of this.
Short answer: Trees are hot and thirsty
First of all, you don’t go crazy. The leaves are falling early this year – plain and simple.
“We’re not in the proper range of natural fall color,” said Carrie Tauscher, state urban forestry coordinator in the Indiana Department of Natural Resources. “Not even for the early fall color, it’s too early for the normal healthy range” to change color and drop the leaves.
In a normal year, the process of leaf color change and then fall would only be triggered when it started to drop below 50 degrees in the evening. Hot summer days and cool nights make for the best fall color, Tauscher said.
That said, it hasn’t been a normal year: Central Indiana entered a notable and documented drought in mid-July. You might think we’ve had thunderstorms all summer long, but a downpour for half an hour is very different from the same rain over several hours. The former simply drains and does not actually penetrate the soil and up to the root system.
These infrequent and rapid torrential rains can help your perennials or your grass, “but not your trees,” Tauscher said.
So what everyone is seeing now is a stress response in their trees. To the keen eye, they may have noticed duller greens in late July and early August, as the trees were thirsty for water and cooking in the heat. And as summer wore on and fall approached, it became more and more obvious to everyone as the leaves began to fall from their branches.
Long answer: Give the trees a drink
What people may not be seeing is what’s going on behind the scenes – or barking, if you will.
In the fall, what is supposed to happen is that the trees bring back all the good stuff, called their chloroplasts, and store them in a layer of tissue over the winter. Then in the spring, when the buds start, they will push these chloroplasts and pigments back to the leaves. This is the normal cycle.
But when a tree is under stress, one of its survival tactics is to remove those “expensive” structures and pigments – things that take a lot of energy to make – sooner than usual. They hold it back in the hope that they will have enough nutrients to survive and sprout again in the spring.
It’s a process called abscission, Tauscher said, where trees cut off these chemicals and release the leaf. It’s a moisture retention strategy, and this year is a glaring example.
“Now the tree has given up and said ‘we don’t have enough moisture to keep you alive,'” Tauscher said, “so they let the leaves go.”
This has been a particularly stressful year as the Midwest has experienced a wetter than usual spring. This means that the plants and trees got bigger than usual because they received a lot of rain and adapted to wetter soils. And then it got dry and they couldn’t get enough moisture to support each other.
Some trees will be affected first, according to Mike Volz, district manager at Davey Tree Co.These are species that need more soil moisture, such as river birch, ash, red maples, silver maples. and bald cypress trees.
When stressed, many of these trees ignore their fall color and go straight to leaf fall. Upland species, those that are used to less water, will be a bit more resilient.
Many people often think of watering their flowers or even their grass when conditions are hot and dry, Volz said, but few believe trees need watering as well. Even native species can battle the unusual weather conditions that have become more common with climate change – wetter springs followed by hotter, drier summers.
Even though we’ve had rains in the past few days, it’s still not enough to make up for all the water the trees haven’t received during the summer, and residents can do a lot to help their trees.
If your tree is bright red right now, or if it’s a dull yellow or its leaves are falling, Tauscher said you need to water it at least once a week with 10 to 15 gallons of water. The root system will continue to grow until the soil freezes, which will help it regain the moisture it needs to survive through the winter.
It won’t make the trees green again or grow new leaves, but it will help them be healthier during the winter and in a better position next spring.
Tauscher suggests a few ways to do this: fill a few 5 gallon buckets or a few large bags with holes in the bottom and place them near the trunk of the tree. And if all else fails, you can put a pipe directly on the small tree. She insists on watering the root system, not the leaves.
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The most important thing you can do, said Volz, is test the soil for moisture. Dig a small hole about 6 inches deep and place a probe there or your finger and feel how wet it is – this is how deep the water reaches the roots. Then water until you feel the moisture has seeped that far, he said.
Stressed trees are more susceptible to other problems: pests, fungi, etc. So watch them next year, as it will take more than a season to recover, experts say.
And when in doubt, call an arborist or tree service to make sure your trees are as healthy as possible.
Do you have more questions about what is going on with your trees and how to keep them healthy? Ask us and we will find it for you! Submit a question to the Scrub Hub using the form below.
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Call IndyStar reporter Sarah Bowman at 317-444-6129 or email [email protected]. Follow her on Twitter and Facebook: @IndyStarSarah. Connect with IndyStar environmental journalists: The Scrub on Facebook.
IndyStar’s environmental reporting project is made possible by the generous support of the non-profit Nina Mason Pulliam Charitable Trust.