I was meaning to update this.

I put one in the ground and the other two in larger pots with some manure pellets and bonemeal thrown in, they're all looking a lot better with nice green leaves.

Not quite sure what I'll do when they need even bigger pots as they're currently in the biggest I've got.

I've planning on moving next year so I don't want to 'waste' them all in the ground when fruit is still a long way off.