Lavender

I agree that they often fail. I found mine thrive in poor dry soil and of course they are a short lived plant so I replace every 6-7 years

I live in France and have a hopeless record with French lavender...lol!
My last two were doing really well and then I got up one morning to find that one of them looked as if it had been hit by a tornado!
The other succumbed to lavender beetles... :(

I wish Rosemary grew better here, I find them easier to grow than Lavender but with all the good qualities (except cold hardiness). It's one of those plants that is hard to keep alive sometimes but always worth replacing. At least they are easy to grow from seeds!

We do rosemary here, Rk. Just stick it in the ground and away it goes. We get really, really cold winters but they don't (usually) last long. And we have really poor soil with calcaire (calcium limestone?) never far below...
Clematis, oleanders, lavender, sunflowers, wisteria and of course grapes...they all love it. And so do roses!

Tried and failed :(. I have tried so many things that are not hardy here: Daphne odora, Rosemary, Cercis chinensis and even crepe myrtle. Surprisingly, a few of the crepe myrtle are 3 years old and alive though. Always worth a shot but at this point lavender is actually easier haha. I do have potted rosemary in the cold frames for winter though.

Ah, now the French love myrtle jam, Rk! It's bay trees that I have a problem with...sometimes they last through several winters and you think they're going to be fine and then suddenly, gone, just like that. I'm nursing a little one right now, but I haven't got much hope for it.

You must be warmer than us, I have no hope of even trying a Bay tree. If I am thinking of the right tree anyways. How cold do winters get there?

We can go as low as minus 20°C - but, more usually, minus 14/15°...only for a few days at a time, though, usually...

But there are often days in November and Febuary, when you can sit out in a T-shirt. We also have a really high rainfall. It's really a very nice climate...of extremes! lol!