Do you mean the leaves have appeared with a brownish edge to them? What variety of Ceanothus is it, do you know? I'd expect the evergreen varieties to possibly have burned edges to the leaves in this way due to the sudden temperature drop in February, but I imagine if yours is deciduous, it wouldn't have even been budding back then.

Thanks Bamboo. I'm not sure what variety it is as it was here before we moved in, but it's very tall - about 20' - and is deciduous. I think you're right and it has been burnt by the drop in temp. I'm hoping it will recover.