This is an infestation of Spiny Witchhazel Gall Aphid (Hamamelistes spinosus). During its life cycle, the aphid alternates between two host plants: witch hazel (Hamamelis spp.) and birch (Betula spp.). The feeding by these aphids causes corrugations and furrows in the leaves. Affected leaves may turn yellow and may prematurely fall off of the tree. 

Most often, control of these aphids is not necessary. Many natural predators such as ladybird beetles, syrphid flies, soldier beetles, and parasitic wasps are active at this time of year and usually move into the area to reduce the aphid populations. If your birch is new/young and populations are high, you can use a low-impact material like horticultural oil to minimize the impact on the beneficial insects that are present. There is more information on the following page of our website.

https://extension.umd.edu/resource/shade-tree-galls

Christa

You're welcome.

We cannot say for sure what is going on. This looks like it may be a Japanese anemone and is usually a pretty tough plant. The wilting/decline  may be due to several issues: such as tree root competition for moisture and nutrients, site is too wet or too dry, etc. We notice some black lesions on the stems and the plants can be susceptible to possible disease issues due to poor site/environmental conditions. 

At this point, the bed looks like it may have excessive mulch around the stems, a lot of leaves, etc. Clean up the bed and check the soil moisture. Make sure it drains well and has good air circulation.  If too wet, let it dry out. Cut the affected parts of the plant back to healthy tissue, groom, and get rid of all the dead stuff.  Make sure mulch is thin and kept away from the base of the plants. Monitor the new growth and you can send us more photos if you notice additional symptoms. 

Marian