Prone to root rot. Looks like you have them sitting in saucers. Should have been taken out of the black nursery pots and planted directly into the clay pots - which presumably have drainage holes - with nothing beneath to trap and hold water.

Would be alot easier to keep alive planted in free-draining soil, in or on the ground, instead of in small pots.

I also planted them in the ground, but it seems like they are still dying. I've stopped watering them for now, still...they seem to be slowly dying.

Like I said, prone to root rot. If the site is not like a parched Mediterranean hillside, they can be quite liable to blight off. I'd take away the concrete circle and clean out the dead tree leaves. These shrubs want full sun, excellent drainage and a climate that is quite dry for much of the year.

I had the same thing happen to all four of my Provence Lavenders that I planted this year. I returned them to the nursery. I did a little reading and it seemed to me that they had a root fungus, not caused by me.

I find it interesting that you are having the same symptoms with the same plant.

I am letting the spot lie fallow for a while and will try again with another variety (maybe) in a year or two. I DID have a dry spot with full sun. :)

Yes, if they came infected beforehand it might take awhile to manifest. You can't have puddles and splashing in nursery container yards if you want to be sure of avoiding water molds, yet this very situation is prevalent.

Is it coincidence the die back is exactly where the irrigation pipe goes in in both pictures? Lavender doesn't need irrigation. It can survive weeks with no rain.

Hi flora_uk

You say that lavender doesn't need irrigation, but that isn't entirely true. It needs to get established before you can allow it to be drought tolerant. My gallon sized Provence lavenders wilted every fourth day in my 100 degree heat and needed water.

I've grown long stemmed lavenders before, the Grosso variety, and it did the same thing. Once it was established, it hardly ever needed water, but in my area at least, it needed water in the beginning.

Come to think of it, I grew those plants successfully from four inch pots, rather than gallon size. I think I will try that again. The smaller plants seem to acclimate better to the garden.

Until they take root it's like they are still in the pots and not in the ground.

San Jose,
No mulch at all. No water.
Get the mulch and leaves away from it.
Do not water them at all.
They will be fine.
Move that cement border away from it too.