Bought a discounted leprechaun apple tree (granny) looking to espalier in narrow space against east or ENE wall. Will put sleeper down to add 20cm high of soil-soil is


clay and tiny stones (thrown there from prev owner, to be dug up as much as I can). Should tree be 20 or 30 cm from wall? Do I need to cut 20 to 50% of branches? I have narrow spaces 1 2 and 2.4 m away, do I need to plant 1 or 2 companion apples (columnar I guess) near it or can it grow on its own or should I multi-plant ie another dwarf apple 20 or 40cm away?
Also wife might want to place bamboo screen behind it. Can I pot for 2 weeks while we decide?