Posted: 23/08/2017 at 19:21
That won't be a problem Emma. I have a similar narrow bed which runs along a rear fence. It's north west facing, so also gets a lot of shade, but a little sun in the afternoon in summer.
You could grow things like Astilbe and Dicentra there without any problem. Both prefer moist soil and some shade, but are happy with a fair bit of sun if they don't dry out. I have both in an east facing border. Both come in pink shades and also white. Easy to find too - most G.Centres will have a selection. I also grow Japanes Anemones in both those aspects. They can be invasive, but I find them to be ok - perhaps because I have heavy soil. They tend to run a bit more in lighter soil from what othe rpeople say. They seed around but as long as you deadhead, they aren't a problem. They flower at this time of year. Again - pinks and whites and easy to get. If you can achieve a succession of flowering, and use a small range of plants but repeat them, that's the best way of getting a good effect in a small space. You can also grow bulbs there - daffs and narcissus are quite happy with damp soil, although there might be a few of the fancier narcissus which may struggle. Snowdrops will thrive, and crocus take quite a bit of moisture in my experience. There are loads of ferns which will be happy there too, and they will give you contrast with foliage.
Carexes - ( ornamental grasses/sedges) would also give a good contrast. Beware of the invasive one - Carex pendula, but the green and gold varieties are another good foil for perennials, and are evergreen. I also use Euonymous as an evergreen foliage plant which go with any perennial, and they will also grow up your fence like a climber, although they behave like a clump forming foliage plant in the border. I also have a prostrate Gaultheria (procumbens I think) which has tiny white flowers in spring like the bigger types, and red berries in autumn. Glossy green foliage which has reddish hues in autum too.
Heucheras, Heucherellas and Tiarellas will be perfect in those conditions too. Loads of varieties and colours, and very sueful foliage plants. Evergreen too. Don't forget primulas - loads of kinds to choose from, and the native ones are particularly lovely. Hellebores would also thrive there.
I grow all of those here. I'm sure you'll get some other suggestions too.
Hope that gives you a few ideas to be going on with