At what point does rich spring grass become dry summer grass?

[Eddie & Elvis]

As I understand it, in the spring, grass is rich so veg doesn't need to he fed as well, then in the summer, it is dry so veg is needed too. At what point in the year does grass stop being rich? I haven't been giving much veg at the moment (just a chunk of pepper and a slice of cucumber or something like that) but I'm unsure whether I should be?

 

[Piggies&buns]

I still give veg when mine are on the grass - their grass time is built up slowly and their veg may be reduced a little (I may give them three-quarters of their normal veg portion) but by this time of year they are spending spend 12-14 hours per day on the grass and still get their veg dinners!

 

[Eddie & Elvis]

I'll feed them a lot more veg then, thank you

 

[Swissgreys]

I just look at the quality of the grass to be honest.
It has been very wet here this year so the grass is still quite lush and I think of it as spring grass. When it becomes a little coarser and drier then I change things accordingly.
But to be honest I build it up slowly and don't really change their fresh veggie intake that much.