Pot size for fruit bushes - help!

[Debbiedoodah]

I've ordered lots of 2-3 litre gooseberry, blueberry and honeyberry bushes and plan to grow them in containers for at least the first year. After that I may transfer them to the ground or keep in containers (would be ok with the soil I have).

Here is what I need advice on - I also ordered a lot of 30cm / 7 litre pots to put them into as had read that you shouldn't size up too much when repotting and also didn't want to overspend unnecessarily. However now I've popped them in the containers I'm worried I've been too cautious and should have gone for the next size up (40cm, 20 litre). What would you do for 2 year old fruit bushes?

I would just do it by eye tbh. Sizes written down don’t mean much to me.

blueberries need ericaceous compost to thrive though, but this says a pot just a little larger is fine.
www.glut.co.uk/plant-care-guides/blueberry-plant-care-guide
grow blueberries in pots of well-drained ericaceous compost. When you need to re-pot your blueberry, choose a pot just a few inches larger.