Scarlet oak seedling leaves turning red - Ask Extension
Last year on Arbor Day 2023, I got a free scarlet oak seedling at Holden Arboretum. Fine in 2023. Fine in spring 2024. Now about 18 inches high and 5...
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Scarlet oak seedling leaves turning red #868958
Asked May 17, 2024, 8:18 PM EDT
Last year on Arbor Day 2023, I got a free scarlet oak seedling at Holden Arboretum. Fine in 2023. Fine in spring 2024. Now about 18 inches high and 50 leaves. But in the past week many leaves are turning reddish instead of the bright green they were in April. Looks more like October colors than May. Help?! What’s wrong? Thank you very much.
Cuyahoga County Ohio
Expert Response
Based on what I can see in your photo, I can suggest a couple of possibilities.
One is that the coloration is a normal occurrence that reflects the fluctuating weather Ohio has experienced this spring. While we have frequently had higher than normal temperatures during the past couple of months, there have also been extended periods of cloudy, cooler weather. Your oak requires sunlight to create the chlorophyll that turns leaves green. Leaves produced during the cloudier periods may not yet have had enough sun to complete this development.
Here are a couple of articles that describe this phenomenon:
https://mywoodlot.com/blog/red-leaves-in-spring
https://forestrynews.blogs.govdelivery.com/2020/07/03/reddish-oak-leaves-not-a-cause-for-concern/
A less likely, but more serious, cause is a nutritional or other deficiency that has resulted in chlorosis. In addition to the reddish hue, your oak's leaves appear quite yellowish in the photo and, on some leaves, the veins appear a darker green. These are typical symptoms of chlorosis.
Chlorosis occurs when a plant is unable to get the nutrients it needs from the soil. The most common causes are actual nutrient deficiencies of the soil itself, extreme pH levels, or drought.
A principal factor in nutrient availability is soil pH. Soils can be either acidic or alkaline, typically ranging from extremes of 7.5 (highly alkaline) to 4.5 (highly acidic). Urban soils in particular are more likely to be more alkaline, as are areas of the state with limestone bedrock. Cuyahoga County includes such areas [Regions 2 and 5/6]:
https://soilhealth.osu.edu/soil-health-assessment/soil-type-history
Scarlet Oak [Quercus coccinea] prefers acidic soil, so alkaline soil can inhibit it's ability to take up the nutrients it needs for optimal health. However, Scarlet Oaks tend to be much less susceptible to chlorosis related to high pH than other closely related oak species.
Additional causes of iron chlorosis include excessive planting depth, soil compaction, construction damage, and stem and root-girdling roots. Herbicide damage or other mineral deficiencies, such as nitrogen, manganese, boron or zinc, may also result in chlorosis symptoms.
Here is an excellent article about chlorosis, it's causes, and how to manage it:
https://www.extension.purdue.edu/extmedia/BP/BP-27-W.pdf
If you suspect that chlorosis is causing the color anomalies on your oak, I recommend getting the soil tested. This is the most reliable way to either confirm or eliminate a nutritional deficiency. Here is a link to your county OSU Extension site and their soil testing information:
https://cuyahoga.osu.edu/program-areas/agriculture-and-natural-resources/community-gardening/soil-testing
You may also want to ask your Extension Educator if she can either make a site visit or recommend someone else with the expertise to evaluate the situation. She can be reached here: https://cuyahoga.osu.edu/people/morning-starr-robinson-bs
I hope this information helps you raise a mighty Scarlet Oak to shade your property and support our ecosystems.
One is that the coloration is a normal occurrence that reflects the fluctuating weather Ohio has experienced this spring. While we have frequently had higher than normal temperatures during the past couple of months, there have also been extended periods of cloudy, cooler weather. Your oak requires sunlight to create the chlorophyll that turns leaves green. Leaves produced during the cloudier periods may not yet have had enough sun to complete this development.
Here are a couple of articles that describe this phenomenon:
https://mywoodlot.com/blog/red-leaves-in-spring
https://forestrynews.blogs.govdelivery.com/2020/07/03/reddish-oak-leaves-not-a-cause-for-concern/
A less likely, but more serious, cause is a nutritional or other deficiency that has resulted in chlorosis. In addition to the reddish hue, your oak's leaves appear quite yellowish in the photo and, on some leaves, the veins appear a darker green. These are typical symptoms of chlorosis.
Chlorosis occurs when a plant is unable to get the nutrients it needs from the soil. The most common causes are actual nutrient deficiencies of the soil itself, extreme pH levels, or drought.
A principal factor in nutrient availability is soil pH. Soils can be either acidic or alkaline, typically ranging from extremes of 7.5 (highly alkaline) to 4.5 (highly acidic). Urban soils in particular are more likely to be more alkaline, as are areas of the state with limestone bedrock. Cuyahoga County includes such areas [Regions 2 and 5/6]:
https://soilhealth.osu.edu/soil-health-assessment/soil-type-history
Scarlet Oak [Quercus coccinea] prefers acidic soil, so alkaline soil can inhibit it's ability to take up the nutrients it needs for optimal health. However, Scarlet Oaks tend to be much less susceptible to chlorosis related to high pH than other closely related oak species.
Additional causes of iron chlorosis include excessive planting depth, soil compaction, construction damage, and stem and root-girdling roots. Herbicide damage or other mineral deficiencies, such as nitrogen, manganese, boron or zinc, may also result in chlorosis symptoms.
Here is an excellent article about chlorosis, it's causes, and how to manage it:
https://www.extension.purdue.edu/extmedia/BP/BP-27-W.pdf
If you suspect that chlorosis is causing the color anomalies on your oak, I recommend getting the soil tested. This is the most reliable way to either confirm or eliminate a nutritional deficiency. Here is a link to your county OSU Extension site and their soil testing information:
https://cuyahoga.osu.edu/program-areas/agriculture-and-natural-resources/community-gardening/soil-testing
You may also want to ask your Extension Educator if she can either make a site visit or recommend someone else with the expertise to evaluate the situation. She can be reached here: https://cuyahoga.osu.edu/people/morning-starr-robinson-bs
I hope this information helps you raise a mighty Scarlet Oak to shade your property and support our ecosystems.
