Japanese Maple (Bloodgood) issue
I planted a 4 foot Japanese maple (Bloodgood) in partial shade about 10 days ago. I have been watering every day except on rainy days. The upper leaves have developed some browning/drying and look to be being eaten by something (see attached pictures). I was going to give it a good spray of an insecticidal soap, but learned that it might not be a good idea for this type of tree. What are your thoughts?
Montgomery County Maryland
We cannot say what has eaten the foliage on the tree. It may be deer as they will eat anything if hungry enough. You may want to cage/fence it to protect it. Deer will also rub their antlers on the bark of young flexible trees causing some dieback.
Here is good information about deer management for you: https://extension.umd.edu/hgic/topics/deer
We are not sure what condition the tree was in before you bought it. However, this time of year plants are starting to show some senescence and we do not think this is anything to worry about. No sprays are recommended.
Since your tree is newly planted we recommend that you make sure that your tree is not planted too deeply, there is not excessive mulch around the trunk, and excessive moisture. These are some issues that can cause plants fail to establish.
A properly planted tree flares at the base of the trunk at the soil line where it joins the root system. In some cases soil is piled up around trunks at the plant nursery prior to digging the trees up for shipment. If you see this, carefully remove the excess soil or mulch from the circumference of the trunk to the point where the trunk flares out into root growth. Here is more on planting too deeply https://extension.umd.edu/hgic/topics/planted-too-deeply
Make sure mulch is no thicker than several inches and away from the base of the trunk https://extension.umd.edu/hgic/topics/excess-mulch
Watering - every day sounds too much.
Check the soil moisture about once a week for new plants week especially during dry periods. Water deeply if needed. Move the mulch aside and check the soil moisture by probing with a screwdriver about 6 inches deep and feel with your finger. Soil should be damp to the touch. Let the soil dry before watering again. See watering guidelines https://extension.umd.edu/hgic/topics/watering-trees-and-shrubs
Here is our web page on planting trees and shrubs, post planting care, and our blog on Japanese maples and establishing them successfully in your landscape