California Lilac

Do you mean ceanothus? If it has not greened up by now then the shrub is most likely dead. Get your fingernail and scrape off a piece of bark on a branch reasonably low down and if it is green the plant still has life, or try and snap off branches, go as low as you can without disfiguring the plant and if they snap off really easily and are brown on the inside it has karcked it I'm afraid!

I would be inclined to wait a little longer. Although it should be greening up by now the winter was pretty lousy. My garden is only now showing signs of movement that I expected from some things weeks ago so the soil is definitely not warm yet.

If nothing happens in another couple of weeks, then I'd also be inclined to agree with Andrea and say it's 'karcked' (lol) it.

These are only supposed to only last 10 years I'm sorry to say but that hasn't stopped me from planting one a few weeks ago, they are lovely!