I bought some bare rooted fruit trees from Tesco, very disappointed when I unwrapped them how few roots they had, they all seem to have been cut off.
To my great surprise and amazement they are all now doing well. The cherry in particular seemed to be just a stump. It is now covered in leaves though it did get watered, and fed well after planting.
Same here, I had an apple and plum in Feb, the roots were barely there, they now have loads of leaves.
When we were growing for shows, some of our plants had to be brought in. First job was to tip them out of their pots loosen the root ball and give the roots a good haircut. This resulted in a very good plant when it grew. I suspect it is like thickening the top with a good prune. When you cut the branches/stems two more appear in their place. Should be the same for all plants big and small. Trees will lock into place a lot quicker with the new fine roots searching out.
They do need to get their roots into gear here. They need to get down through the gravel etc and into the water table Then they can manage without any more water.
I have a dual pear originally from Lidl which has been very slow, and this year for the first time it has suddenly perked up, and even through the dried period it has been fine. Though only one variety flowered well. The other variety seems to have gone for leaves.
I repeat the standard advice:
A square hole is better than a round one - less likely to make the roots circle*.
No fertiliser until it is established - make the roots range further.
at least 1 square metre of black plastic around the trunk - reduced drying and more stable moisture levels - but water it anyway.
Cheers.
* Presumably the further you can get from a circle the better - triangle or pentagram anyone?