River birch not thriving

Question: We have three River Birch’s on our property in Northern MI.  While none of them are thriving, one in particular doesn’t look as healthy.  They are located near the top of a sloping hill on our property with a western exposure and a lot of sun.  We also have a lot of clay in the soil here.  We would appreciate thoughts on how to make the trees healthier.

responder: Thank you for contacting us!  Replied July 22, 2024, 2:10 PM EDT
response: Hello, thank you for contacting Ask Extension. I need a bit more information from you. Could you send me a picture that includes the entire 3 trees, down to the ground? Also, a picture of the root flare and ground around them? Once I receive this information, I can better determine the correct diagnosis for your trees.

responder: The Question Asker Replied July 24, 2024, 5:01 PM EDT
response: Hi -  Thanks so much!  I had a problem uploading the pics due to the size, so am attaching to this email (will send in more than one if I need to).  I have attached 6 pictures - the root/ground area followed by full tree picture of all three trees.  Please also note I trimmed quite a few dead branches off the trees this spring.  Also, this is a newer  house and the trees were planted in October of 2022.  We do also have them fertilized along with our other trees.  We just feel like they aren’t thriving..  Appreciate any insights you have.  Thanks!  Sent from my iPhone On Jul 22, 2024, at 2:10 PM, Ask Extension <<personal data hidden>> wrote:   ﻿

responder: Thank you for contacting us!  Replied July 24, 2024, 7:35 PM EDT
response: Thank you for contacting Ask Extension. Thank you for the additional pictures that you sent. They truly helped. I believe that you have Paper birches not river birches, because of the white bark. They are beautiful trees, and I had one, but it died here. They usually prefer colder weather, and grow to zone 6a, we are on the border of that zone. But with work, you can hopefully get them to thrive.  To help your River Birch thrive in your Michigan property, you can consider the following practices:  1. **Soil Management: Ensure the soil is well-draining and acidic. River birch prefers moist soil and can tolerate clay.  2. **Watering: Keep the soil consistently moist, especially during dry periods. Since the trees are on a sloping hill, you may need to ensure they receive adequate water, especially during dry spells. All plants need at a minimum 1” of rain/week.   3. **Mulching: It would be beneficial if you removed 3-4 feet of sod out away from the tree, all around, and mulch with 3-4 inches of mulch trees to conserve soil moisture and prevent the soil from drying out too quickly. Do not pile the mulch up around the tree, but leave about 2-3 inches from the trunk open. The grass may be taking up water before it can get to the trees’ roots.  4. **Pruning: Prune your River Birch in late summer or fall after the leaves have fully expanded or after they have shed their leaves. This will help prevent sap exudation, which can be unsightly but not harmful.  6. **Fertilization: If the trees are not thriving, consider a slow-release fertilizer to provide them with the nutrients they need to grow. Look for one that has 6-3-2 as the ingredients for N-P-K. Wait until the leaves have dropped to apply the fertilizer, then follow the instructions to fertilize in the spring and fall.   7. **Pest and Disease Management: Keep an eye out for pests and diseases, such as the bronze birch borer, which can affect birch trees. If you notice any signs of infestation, consider consulting a local arborist for treatment options.  Remember, these are general recommendations and the specific needs of your trees may vary based on their individual health and the conditions on your property. It's always a good idea to consult with a local arborist or extension service for advice tailored to your specific situation. River birch (Betula nigra) and paper birch (Betula papyrifera) are both deciduous trees in the birch family, but they have some distinct differences. River birch, also known as the water birch, is native to flood plains and swamps of the eastern United States, including Michigan. It has a graceful form and attractive bark that is black in the wild and is known for its exfoliating bark, which is particularly noticeable in the winter. It is a fast-growing tree that is valued for its colorful bark and is often used in ornamental plantings. River birch typically grows to be 60-80 feet tall and has a symmetrical branching pattern.  Paper birch, on the other hand, is native to North America and is known for its white bark that peels to reveal a creamy white inner bark. It is also known for its papery bark, which is where its common name comes from. Paper birch typically grows to be 30-60 feet tall and has a rounded crown. It is also known for its fall color, which can range from yellow to orange to red. Here are some publications for your reference: All-season trees: River birch - MSU Extension https://plants.ces.ncsu.edu/plants/betula-populifolia-whitespire/ https://plants.usda.gov/DocumentLibrary/factsheet/pdf/fs_beni.pdf

responder: The Question Asker Replied July 25, 2024, 9:54 PM EDT
response: Wow!  Thanks SO much for the detailed response.  I did take a closer look and think you are right in that these are likely Paper Birch trees.  I will try the ideas you outlined and circle back if I have additional al questions.  Thanks again for sharing your expertise. Sent from my iPhone On Jul 24, 2024, at 7:35 PM, Ask Extension <<personal data hidden>> wrote:   ﻿

responder: Thank you for contacting us!  Replied July 26, 2024, 3:44 PM EDT
response: Welcome!