Under-plants for roses - what's readily available?

Some campanula can be invasive I believe but mine is fine. I just rip some out when it gets out of hand. Haven't had to do that for some time. Don't ask me what type it is though, it's been there for years. Purply blue flower spikes about 12inches + high, foliage is much lower.

At the moment one of my beds is under planted with lucerne not by design but rather by accident with the lucerne springing from lucerne mulch that was spread in October. I've decided to keep the lucerne and see how it affects the bed in the long term. One beneficial affect I've discovered already is despite the heat wave none of the roses in the bed have suffered with sunburn.

That's interesting Ausrose. How high does lucerne grow? Do you think the growth of lucerne gave the rose foliage protection from the sun or perhaps it might be due to root shading?

Yes i'd be interested in that too , cause some of my roses have sunburn .

here is the story on Lucerne, [You must be registered and logged in to see this link.]

Love the lucerne, nitrogen fixing and all that ... although it's in pretty short supply up here right now. How could I have forgotten the forget-me-nots! On my shopping list now!
Another very common herb I didn't mention earlier as a ground cover and filler for roses is good old rosemary. Numerous forms including prostrate - and tough as tough gets. Probably needs to be on the edges of the beds though as, like lavender, it may not enjoy too much watering.
And, yes, Ausrose, I wouldn't be picking culinary herbs from a rose bed that is sprayed etc.