What to plant next to box to fill a gap

[Handsnotwands]

Next to the path?

We have a box hedge, maybe 40cm high, then a gap of maybe 30-40 cm of bare earth (weeds) then the path

I’d like something to fill it, something frothy, low, with flowers

Does such a thing exist?

Lots of things. Nothing that will have flowers all the year round! Try a a dense mass of cyclamen since the ground is likely to be a bit dry next to the box hedge. Depending on species flowers either autumn or spring, and pretty leaves for most of the rest of the year.

Woodland flowers. They cope better with the dryness if they have a good covering of leaf mulch, but bulbs are definitely more likely to survive.

Oh excellent thanks both, that gives me a starting point. We have a big patch of cyclamen in the back garden under a tree. Bulbs also a good shout

Woodland flowers typically do exciting things in the spring when there's no leaf cover, then die down later on. With an evergreen, that doesn't apply, but if it's a low hedge, they're not going to have to contend with much shade either, so I don't think you need to confine yourself to woodland plants.

You could try Vinca.

Thank you mere Vinca looks precisely the sort of thing I’d pictured, off to research

Erysimum is another good option. Doesn't flower year round, but pretty darn close to it; mine currently still has some flowers!