Why Are There Yellow Leaves on Trees in Summer?

Why Are There Yellow Leaves on Trees in Summer?

Rich, green leaves are a staple of summer. They’re crisp, bright and a pleasant addition to every landscape. Plus, we love their shady canopy on sunny days.

So if you spot yellowing leaves on your trees, you want them to return to their green glory. An Ontario-based reader recently had a similar goal. She asked us why her river birch leaves were turning yellow and falling off – and how she could fix it.

There are many reasons why you too could see these symptoms. Run down the checklist below to help diagnose your tree.

Test 1: Test for dry soil

If trees aren’t hydrated, the leaves can turn yellow as they try to conserve water.

Test your tree’s moisture by sticking a screwdriver into the soil. If it’s hard to push in, chances are the tree is thirsty and could use a deep watering.

Test 2: Check soil moisture

If the screwdriver test proves there’s moisture deep into the roots, water less.

Your reflex might be to water at the sight of suffering leaves, but overwatering can also lead to yellowing and leaf drop.

Test 3: Inspect and treat

Yellowing leaves and premature leaf drop may point to a leaf disease or summer pest infestation. Consider a free tree inspection to identify the pest or disease and the best treatment.

If an infestation is ruled out, the checkup may reveal a deficiency called chlorosis, which strips leaves of the chlorophyll needed to keep them green.

Begin by performing a soil test and adding any necessary soil amendments. Fertilizer also replenishes lacking nutrients, which in turn helps your tree. Remember, these actions need to happen on a regular basis to have a lasting impact.

Why, specifically, is my birch or river birch getting yellow leaves in summer?

If you, too, are seeing yellow leaves on your birch tree, there could be a couple reasons why.

Run through this checklist just for birch trees to find out what the problem is:

  • Are there spots on those yellow birch leaves? If so, the problem is likely a leaf disease.
  • Do you see something sticky on the bottom of the leaves? If so, it’s probably an insect.
  • How much are you watering? As their name implies, river birches love to drink water. In the summer, when the water is limited, they’ll drop leaves if they get thirsty enough. To remedy, deeply water your birch tree each week, and add mulch to conserve moisture.
  • How hot is it? If it gets too hot for too long, these trees drop leaves to conserve energy. This happens most often to newly planted trees. They toughen up a bit as they mature because their root system becomes better established.
  • Didn’t see any of the above? Check the soil to see if there’s enough iron (or if the soil has too much pH). Remedy the problem with soil amendments or treatments.

Have a question about the appearance of your tree? Comment below for help from our Davey scientists!

  • The Tree Doctor September 19, 2018 >Hi Yong Suk, I would recommend having a certified arborist come out to take a look. They will be able to provide an accurate diagnosis and prescribe a treatment plan accordingly. Unfortunately, Davey Tree does not service your area. Here is a resource that can help you when hiring a certified arborist or reputable tree care company: http://www.davey.com/arborist-advice/articles/hiring-a-tree-service-provider-or-an-arborist/. Best of luck to you, Yong Suk.
  • The Tree Doctor September 19, 2018 > Hi Janet, There are several possibilities to why this might be happening. I would recommend having a certified arborist come out and inspect the tree. They will be able to make an accurate diagnosis and prescribe a treatment plan accordingly. You can contact your local Davey Tree office directly at (512) 271-2810. You can also complete a consultation request form on their local web page here: http://www.davey.com/local-offices/austin-tree-service/. The office will reach out to you as soon as they can to schedule a free consultation. Here if you have any more questions, Janet.
  • Yong Suk Catena September 18, 2018 >Our bitterbrush branches and leaves partially turn light brown. I don't know what to do with it.
  • Janet Atwood September 17, 2018 >I have a red oak and the leaves got black spots on them and would fall off. Now the leaves are more brown and falling off.
  • The Tree Doctor August 8, 2018 >Hi Kevin, I recommend contacting a certified arborist and having them come out to evaluate the tree. They will be able to make an accurate diagnosis and prescribe a treatment plan accordingly. You can contact your local Davey Tree office directly at (972) 892-3034. You can also visit their local webpage and complete a quick consultation request form here: http://www.davey.com/local-offices/dallas-tree-service/. Best of luck to you, Kevin.
  • The Tree Doctor August 8, 2018 >Hi Linda, In general, you should keep the root ball and an area a foot or so outside of the root ball moist on newly planted trees. This maximizes the ability of new roots to begin to grow at the edge of the ball and push into the adjacent soil. Hopefully, any excess water can drain away, but that will depend on the soil characteristics at your planting site. Because many roots are disturbed/lost during the digging/transplanting process, it is common to see some foliage yellowing/dropping during the period after planting. External weather conditions often will affect how much of the crown is affected. Hot, dry, windy weather places a great deal of moisture stress on the tree that the redeveloping root system may not be able to handle. Cooler fall weather should provide some relief. Hopefully, this helps. Best of luck to you, Linda.
  • kevin Lee August 7, 2018 >leaves are turning yellow and falling off
  • Linda Richards August 3, 2018 >I have a newly planted Katsura tree. It is early August and Imhave been watering via a slow release bag pretty regularly. A, I overdoing it or not enough water..or s this characteristic of a Katsura. Thank you.
  • The Tree Doctor July 12, 2018 >HI Tracey, Unfortunately, Davey Tree does not service your area. Here is a resource that can help with hiring a certified arborist or reputable tree care company: http://www.davey.com/arborist-advice/articles/hiring-a-tree-service-provider-or-an-arborist/. Best of luck to you, Tracey!
  • Tracy McMillen July 10, 2018 >I would like my soil composition to be checked for nutrient deficiencies, please.
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