Have a look at Knopper galls
9 cms is too small to plant out in autumn, pot on as the roots fill the pot, I'd go to 1L pots from there.
six hills giant won't make a hedge for more that a couple of months in the year.
I tried translating freely hedge from auto correct but failed
It's not a good time of year for tree planting. If you prepared the hole well, loosened the soil around it, loosened the roots on the cherry, soaked it well so the root ball is wet, that's all you could do. Keep it and the surrounding soil moist but not wet and speak to it nicely
start with the camera icon and don't try and upload too large a photo
when you say transplanted, do you mean dug up and moved or planted a container grown plant?
I see a nice plantain on the right, broad leaves, probably the one you refer to. A weed
I'm a bit suspicious of the grassy looking one, middle left, as well
I cut mine anytime when the leaves are off.
poppies can be tricky, I find they do best from an autumn sowing.
my garden is far from enclosed, near Peterborough uk