When does bird nesting season finish?

[SuperHangOn]

I have spotted some (I think) blue tits flying into a hole in the eaves of my roof - when will they naturally leave? I don't want to harm them but obviously want to block the hole in at some point. I will put a bird box at the end of the garden for them instead!

Cheers

[Big Al.]

We live darn sarf, and we don't normally cut our 140 foot hedge until the middle of July, just to make sure the little'ns are out of their nests.

[Johnnytheboy]

Gardeners at work say July is fair game.