Plants for shade border

Messynessy

I have a north facing border against a white wall. It’s currently empty but covered with weed membrane and slate chips. I’ve got lonicera purple storm, pieris and skimmia to plant in it but I’d like to know any suggestions of what might be nice with these? The soil underneath is clay. 

Fairygirl

What are the dimensions @Messynessy, and what sort of look do you want? Perennials? Groundcover?
If the soil's moist enough, there's loads of plants which will suit very well, depending on what room you have 

hannahrecas

I’m thinking maybe some sort of grasses in to contrast with the shrubby type plants you’ve chosen? 

Ophiopogon
Liriope muscari

Messynessy

It’s about 4/5 metres by 1 metre and the soil is usually moist. The plants I’ve bought are not huge so I’d like something to fill the space a bit. The slate chips and clay make it quite hard to work with so ideally no annuals or anything that needs lifting. It’s at the front of my house so low maintenance is best. I like the idea of something grassy @hannahrecas thanks for the suggestions. 

Woodgreen

In a similar border I have sarcococca confusa, neat and evergreen with scented flowers throughout winter. Geranium macrorrizum does well.  It spreads but gently and it isn't a big excavation job to control it, pieces pull out easily. It comes in white, pink and magenta.

Fairygirl

The shrubs you've mentioned will eventually fill a metre width easily, so there won't be room in front of them, and not a lot in between once they're mature. Pieris can be become huge depending on the variety, although you can prune them.
Anything you plant near them will get crowded out, so it may be better to use bulbs in front, that you can lift over time and plant elsewhere. Snowdrops, and the later Leucojums which are a bit taller, will be fine, and many standard daffs. Chionodoxa, Muscari  too, will all be fine in that aspect.
In between, you could have things like Dicentra [it has a new name, but you'll still find it under that] Polemoniums [Jacob's Ladder] and Japanese anemones will give some height, and they flower at different times so that would give you a bit of interest from spring until autumn. The first one is a bit more spreading than the others - they're more upright and will be fine until the shrubs fill out completely. Any gaps can have groundcover like Saxifrages, Ajuga and Heucheras. The smaller, evergreen Carexes will be fine too - ones like Evergold and Everest which have good colour. Hakonechloa is also excellent for shade.  Most are very easy and need little to no care.
I know you don't want annuals, but it might be worth doing some to fill the gaps until the shrubs grow. 
Bear in mind that your soil will become drier due to the shrubs, as they grow. If you have slate, that means you can't add mulches of organic material either, which is highly beneficial, so you might need to use liquid feeds now and again instead. Unfortunately, that's never as good as compost, bark or leaf mould etc, which is the drawback of hard materials as a mulch 

Messynessy

Thank you for such a helpful, detailed reply. I will have a look at those options. The slate was here when we moved and would be difficult to dispose of so it will have to stay for now. It does make adding or taking anything away much harder though. 

Messynessy

Just another quick question. Do you think I should lift all the slate and membrane and improve the soil under the whole area or would it be ok to just dig out planting holes?

Fairygirl

It's quite a lot of work to do that @Messynessy, but would be worthwhile if the border's been covered like that for a long while. The soil can often be pretty poor.
In the long run, it's cheaper to prep the site properly, and then the plants will get off to a good start, and thrive better. If you want to keep the slate, just put it around the plants without a membrane though.   

didyw

Have you tested the soil? The pieris and skimmia will prefer a slightly acidic soil.  Or maybe you have seen those, and camellias or rhododendrons growing in neighbours' gardens - in which case it is a fairly safe bet that your soil is acid too.

Fairygirl

They grow in neutral soil no problem too, as long as it isn't at the alkaline end of neutral.