I find Dunnes fruit to be seasonal tbh but not as in time of year for harvesting. I eat their grapes from July till November, otherwise I find them soggy (I like a crunch). Their pink lady apples are only good during summer/Autumn as well, otherwise lack of crunch. Same for their strawberries but they're bad value anyway so I tend to avoid them mostly. Their oranges (49p) have been terrible in the last 3 months and I find they improve in Feb or March. At least the latter is obvious from look and feel.