Can anyone help me with care of phormiums, at the moment they are looking yellow and shrivelled.
I am watering them regularly.
I wouldn't worry too much - they're pretty tough, and will survive extreme dry weather. Even ones which look dead, can spring back to life when normal conditions return. the more fancy, variegated ones can be a little more fussy.
Are they in the ground or in pots? In the ground it's easier for them.
You can remove old, dead leaves right back to the main stem/base - but be careful as they can be very sharp! If you want, you can wait until better weather returns and they perk up.
It's a place where beautiful isn't enough of a word....
I live in west central Scotland - not where that photo is...