It's difficult to judge how much space you have between your box hedge and the house but perhaps you could have some viburnam tinus there which is evergreen and produces white flowers from winter to spring. I thought of a pyracantha like a couple of the others but if you get spiked by it's thorns it is very painfull. Well done though Amanda for a fabulous job you have done so far. Keep us all posted with it's progress as we will all be very interested.
I think it looks lovely already, Amanda! Verdun has come up with some good plants for you. Personally, I've always wanted a Japanese rock garden so would try putting an interesting looking rock in the centre and rake circular 'ripples' around it in the gravel.
Evergreen grasses are nice in winter, the varigated low growing one's add extra colour when nothing much is in flower. Some are fine even after a covering of snow, three to four clumps along the left hand side of your garden would take the edge off the paving. .
There are some brilliant suggestions here. I like the japanese idea, maybe you could grow an Acer in a pot which would complement that.
Around the outside I would probably keep it simple and fairly formal. I think Ophiopogon sounds great. There is a green form as well so you could make geometric shapes. Maybe as Verdun says you could add some blue festuca as well.
How about purple flowering thyme
On the practical side - I'd get the crack checked out soon - it's probably due to the weight of the brick pier above it and might just mean those few bricks being chipped out and replaced. Not a big job - and not as big a job as it'll be if that pier sinks down a bit and compromises the structure at the top of the bay - you'll have water getting in then and that will be a problem.
Also, make sure that whatever you do doesn't block those air bricks.
(sorry, the ex was a builder )
Good advice fro Dove. The crack is not that noticeable but does need sorting out and would be camouflaged, along with any repair work, by just having plants in the soil. No need for tubs or planters and less watering for you in summer.
For winter interest, I find carex buchananii and its newer forms like Bronze Beauty look good. Mine never seem to flwoer so no probelms with self seeding and tehy just need a comb through with a rake or gloved hands in spring to remove the dead foliage. Look amazing with cream or white daffs interplanted come spring..
What a great job you have done!
Some brilliant suggestions have been made already. I have a small front garden - probably about the same size as yours, with a similar aspect and a lime tree. I find that even in such a small space I have had to think about varying amounts of shade - some of my planting has to cope with quite deep and dry shade when the tree is in full leaf. I have a lot of spring flowering bulbs that do their thing before the leaves come out. Near my lime tree I have planted epymediums, geranium macrorhizzum, japanese anemones, pulmonaria and pachysandra. They all cope with the dry shade there. Once the bulbs have gone over I rely a lot on interesting foliage - others have already recommended heuchera and grasses, and I find Carex Evergold is happy anywhere and have repeated it through the borders to link everything together. How about a daphne under your window? I have D. odora ‘Aureomarginata’growing in quite a shady spot, seems quite happy. It shouldn't grow too tall, but if it does, this variety doesn't react as badly to pruning as others do. Or what about a hydrangea? coming back into fashion, I hear, and there are some fabulous varieties. They're not evergreen but you can leave the dying flowers on all winter and they have a sad beauty.
With small gardens, especially formal ones, I think you either have to limit the variety of plants or stick to a restricted pallette of colours, otherwise it can get a bit too busy. I am a plantaholic, so went for the second option and chose plants which either had variegated (silvery) foliage, or had pink or white flowers. I've added in some purple since to stop it looking too sugary. Still had an immense amount of plants to choose from!
Good luck and do keep us posted.
Thank you all so much for the suggestions. I'm absolutely blown away by you taking the time and trouble to think about what I could do! I need to get stuck into looking up and finding out about all the plants that have been suggested.
I'm beginning to think I should have made the border under the window a bit wider. I thought it looked about right before I planted the box but it's only about 50cm now. Live and learn... it's too late now to change that though, so I need to find something that will grow quite upright and not be too bushy. I would really really like to have ceanothus there as a sort of blue flowery hedge, but I don't know if that's a bit silly. I read that it needs a lot of sun and gets very big?
As for the crack, thank you dovefromabove and obelixx for thinking about that too. The house is full of cracks but I had a structural engineer friend of a friend look at them and he seemed unimpressed by what I thought were scary big cracks everywhere. He said it wasn't subsidence and no need to do anything. So that's why I just want to camouflage this one with planting so I stop seeing it and worrying about it anyway.
Off to look up all your great plant suggestions (and then no doubt come back with more questions...)