Lavender hardiness.

It's very hardy, provided you do things right.

Years ago, I used to buy 1-2 lavender plants every spring, and plop them into the best spot in my garden: a southern slope in front of a wall, with lots and lots of horse shit underneath.

They died, every year, sometimes even before winter hit.

Then one year I got an extra lavender after I'd planted my usual ones. As I had no other spot to put that into, I put it on a shady north slope, in a spot where there used to be a sandbox, decades earlier.

This one survived many winters and flowered profusely.

I didn't water it, gave it no fertilizer whatsoever, just left it alone - all I did was pick its flowers, in high summer. Very pretty, nice scent: a large lavender in full flower is simply lovely.

So lavender needs sand, in our climate. In top-quality soil the plants get too leggy and can't handle any adversity - like a night of mild frost, or too much rain.

If all you have is top-quality soil: add a few wheelbarrows of sand and plant your lavender at the top of your new sand heap.

Also, lavender can't take wet feet. At all.
If all you have is clay: add a few wheelbarrows of sand to that, too, and put the lavender into the top spot.

It'll thank you for it.

No mulch, no coverings in

No mulch, no coverings in winter. Of course, the north slope has snow for quite a long time, taking care of the "all the snow is gone while the ground is still frozen and the sun is just blazing down" death by thirst of a lot of evergreens.
Not that lavender actually is evergreen, at least up here ...

That's californy for you.

That's californy for you. But, JR, is it in sandy soil?

Peat might work, but might

Peat might work, but might be too acidic. Dunno ...

It's at home in the

It's at home in the Mediterranean mountains. Sand and stone, and lots of sun. You figure out if that fits your location or not.