I have a row of tall evergreen trees, I guess 25-30 feet tall. Don't know what they are but we've thought perhaps some sort of tree laurel due to the waxy, oval leaves - though much more delicate than normal laurel leaves.
The last week after all the snow in the UK, the leaves have gone limp and brown... What could cause this sudden affliction to all the trees?
I think it's the Portugal Laurel, Prunus lusitanica and it really does not look well at all. As far as I recall, you are in the North of England, where it is inclined to be wetter, even if that wet has fallen as snow.
I hope it isn't phytophthora infection at the root, because that's what it's reminding me of - the other possibility is its just got caught by sudden very cold temperatures, but usually, these shrubs are pretty hardy, tolerating down to -15 deg C for short periods. However, if you had a mild spell followed by a sudden blast of cold (as many of us did in the UK), it might just be damage from that.
A phytophthora infection at the root will progress and the shrub will die back even more, at which point it should be completely grubbed out, removing as much root material as possible. This infection is also more likely if your soil is heavy clay, information in the list here https://www.best4hedging.co.uk/the-10-most-common-pests-and-diseases-of-hedging-plants-in-the-uk-i143m, you'll need to scroll down.
In the meantime, I'd suggest keeping a watching brief and monitor its progress - if you spot new growth arriving that's healthy, you may need to cut back to wherever that is, but give it a little time.
