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.

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

Welcome!