They like acid soil and hate to dry out, could it be that they suffered from not enough water? Alternatively, where we they when you bought them? Under shelter or inside? If so, this could be exposure damage if they were not hardened off before planting out.

Thanks for your quick response. I bought them from homebase and planted them on the top of a bank to a stream (which is dry 9 months of the year). They have some shelter. Ive only recently became interested in plants and wonder if the ferns nearby are of any signifigance to the soil type in the area?

Sounds like water might be a problem then, in terms of not enough of it. As to the ferns, some thrive in dry conditions, some in moist, depending on variety.

I am growing blueberries in large pots because my soil is to alkaline. Don't water them with tap water - they hate it. Use rainwater. If I don't have enough rainwater ( I leave in the Anglia region, so very dry), I use the water condensed from my tumble -drier as it is pure H2O without any alkaline minerals in it. They seem happy.

Thanks for ur advice, I am giving them extra water to see if they recover although i have noticed some of the leaves more reddish than brown. Is there a way to tell how alkaline the soil is without testing and is testing expensive?

You can buy a kit that isn't too expensive, but the best guide is what's growing round and about in surrounding gardens/areas - if there's Pieris, Rhododendron, Azalea and blue Hydrangeas, then the soil isn't alkaline.