I am sorry for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
Your Mexican heather may return but most likely from the base. It is slow to return so wait until the weather really warms up before giving up on it. You can prune out the brown top parts in the meantime. If you get to green fresh stems don't prune it back any further.
Thanks for the question. Please stop in again soon!
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