| Could it be sun damage Woori. I grew lots of tree ferms down in Melbourne and that was the only thing that harmed them. I remember one day when it was 43 degs they were scorched something terrible even though I kept puting the misting system on they still got burnt went blackish brown on the tips and broke off. The only other thing could be lack of water, maybe that happened before the rain as I know it had been very hot down there the week before. You should water from the top if they are new as they have no root system. If it is only a couple of fronds I would not worry to much, as it wont be long and they will be replaced with lots more. I think the only problems tree ferns get is some kind of scale but I dont really know for sure as I have never had any problems with them. Hopes this helps a little. MM. | 
