If you're going to say not "taller than the gutter" then you should say how tall that is or provide a picture. We can't see your gutter!

American Beech (Fagus grandifolia). It has smooth white bark. However, it is not multistemmed.

We seem to have two divergent views. The first, posted by amazing_hedges (who is me) is that amillaria is always present in the environment and can be fought off by healthy plants. The second is by bboy that amillaria creates a dead zone into which no woody plant should be planted. I am going to hold out that both views may have merit and also that I may be wrong. but I am going to hold to my original view and challence bboy. He states that no woody plant should be planted. No tree, no shrub, no rose. For how long and for how far? In the stump area? In the drip area? in the neighbors' yards 60 feet away? For a quarter mile? If the area is limited, why not just apply a fungicide, after a time reintroduce micorrazae, and plant what one wishes? What do we see in the forrest? Do we see expanding dead zones cause by amillaria or do we see individual trees infested with amillaria surrounded by healthy trees? How does our experience in the natural forest relate to our experience in the urban forest? One key experience with amillaria in Southern California are the Blue Gum eucalyptus which look healthy one day and fall over the next. I have been called to clean up a half dozen of these in the past three decades. I have noticed that all of these had extensive rot at the bawho bothered to look could have noticed. Indeed, the German physicist Clauss Mattock taught us that a tree rotted 70% hollow was just as strong as a solid tree, but that a tree rotted 90% hollow could not stand long. All of these trees were planted in rows, standing next to trees that showed no signs of affect from amillaria. I do not contest that amillaria can "come out" of a stump and infect other plants. All life forms have methods of propagation. Yet I do perceive amillaria as ubiquitous (always present) in the environment to attack weak plants and to digest dead plant matter. i do not see a need to declare dead zones around amillaria activity.

Cedars and ferns would = damp, if these are lady ferns. If you are in a low area, out away from the continuous influence of Puget Sound (Sunset 4), you will have different choices than if in closer (Sunset 5). In the milder part there are various broadleaf evergreen trees you could try, these being more cheerful (having the appearance of reflecting light instead of absorbing it) than conifers it would be advantageous to replace the cedars with at least some of these, if possible.