planting up a wall with lavender (and campanula).

REMF33

I have a small wall with a cavity in it, which has a box hedge and self-seeded campanula. The box hedge succumbed this year (as you can see in the photo), so was thinking of planting it up with lavender, in the spring. Possibly with rosemary. I'd quite like to keep campanula/plant some more. Several questions: will lavender work? If so what sort? Will campanula work with it? 
This was it this spring.
I think the wall is about 9ft long. I imagine that the depth of the cavity is the height of the vertical bricks.

Robmarston

Why not just let the campanula run riot?  I love the stuff and on a wall it looks lovely.  

REMF33

Well I did, really. This is as riotous as it gets Yes, I love it too and want to try to preserve it, or plant some more. But it's not there all year and the hedge looks awful when it's not got camapanula running through it. I also want a bit of height. The wall is low and separates us from the pavement.

bertrand-mabel

In a sunny position the lavender would do well. Hidcote is a reliable one. Rosemary would also do ok there and both give lovely scents and the latter great in cooking whilst the lavender flowers make lovely scented bags.

REMF33

Hidcote then, maybe.

Loxley

Those prostrate forms of rosemary might be fun. Also consider Erigeron karvinskianus. I wonder if sedums would tolerate it? (The small ones would but I'm thinking about the taller types like Sedum Matrona). I bet they would!

Borderline

I personally think Lavender with Campanulas are too similar in colours. Since you had a Box shrub growing in the space, something like Euonymus Fortunei may do well there, provided there is enough root space. They don't grow that tall, but may offer a more permanent structure similar to Box, but far more resilient to all types of conditions. Easily maintained through pruning, and the campanula can scramble through it and stand out better.

REMF33

Ok will think about that. I did like the idea of lots of bees and other insects coming...

JennyJ

Also, bear in mind that lavender likes lots of sun and might not be happy with the campanula growing over and through it. Dwarf berberis might be another possibility for tough little shrubs.