They may just be suffering from cold, i have ssen a few at various nurseries completely brown but sheltered. Could they have dried out over winter if they are undercover or from the wind? Will they come back - not sure, they may do but will probably hang onto thier leaves until new ones form, plus this adds as extra protection for the new buds. No real way of telling if they are 100% alive until the weather warms and new growth begins.

I would suggest giving them a quick feed of epsom salts. About a table spoon to a gallon of tepid water. It is possible they are having difficulty absorbing nutritional salts and this will help.

Wind has burned the top of my bay tree but in pots it could be that the soil has frozen and the plants have been unable to access water. Bay is fairly hardy once it gets growing so I would wait and see.

This does not sound good really, they are an evergreen so should not be brown & dry. Do they get plenty of water if you say they are sheltered, maybe that is the problem. You may have to wait as everyone says until things start to re-grow. Good luck.

thanks to all of you, I will water them and hope for the best when the better weather comes!