Hi. Some advice please.

I purchased some Calluna (don't know variety) at Trader Joe's in little pots about a month ago. It was beautiful- beautiful green foliage with lots of pink to lavender flowers (some white).

I planted it in my garden in the sun, and within a couple of weeks the leaves turned brown. I have Erica darlyensis growing in the same location successfully- beautiful green leaves on the Erica.

Is this a normal seasonal cycle for Calluna or is there a problem? We have not had a real frost yet but at night it sometimes gets down to around 40 F.

Thanks in advance,

anitje