I have an area along a flagstone walkway where I want to run a border of Muscari and daffodil bulbs, with an overplanting of Ajuga. Behind that is a row of Pygmy Barberries.

Last year was my first with Ajuga (Bugleweed), so I'm not sure how compact they get when fully established. According to pics I've seen on the web, they look pretty dense. For those familiar with Ajuga, will bulbs be able to break through in the spring?

If not, can anyone recommend a low growing groundcover as a border along a (sunny) walkway? Ideally I'd like something really compact so the walkway doesn't get muddy during rainfall. A plastic border in that area for various reasons would not work.

Thanks