Hi Sara. I'm guessing it's going to be shady - and dry too? What kind of look do you want and can it be seen from the house? If you can see it from the house you might want to have winter and spring interest and you can always put some bulbs in amongst other planting. White plants help in darker areas as they stand out and if you can get some golden foliage in there too it will lift it. Hardy geraniums will be fine there and there are loads of bright ones if you want a burst of colour rather than white. Ferns are useful in those conditions too and you can get some lighter, more golden ones, and also some pale aquilegias and white hydrangeas. White wood anemones for the spring and also the Japanese ones for this time of year will grow there. Foxgloves for verticals. I see you have a fuchsia there already- I had a very pale pink one many years ago and that could be a useful plant as it will lighten a shady space. The fir trees will take a lot of moisture and nourishment from the soil too so you'll need to use plants which thrive on poorer soil or be willing to put loads of manure and compost back in before planting. I'd do that anyway as the ground will be pretty starved.
Don't know if any of that's any use!