Spurred on by the encouraging results of my nettle cordial (not officially ready til tomorrow, but I had a taste yesterday and it was lovely

) I'm thinking about other forraged drinks

I know we definately have Elder, but before I go scouring all 130 acres looking for the right tree, I just want to check when the usual time to harvest the flowers is ? I'm just south of Glasgow, 1000ft above sea level, if that makes a difference ?
If I've missed the flowering season, it'll just have to be Elderberry cordial later in the year instead

I know you guys will know, so many thanks in advance

Karen x