In my food forest I basically have fruit tree guilds, 4 feet wide in 150 foot rows. Main tree in center, with a perennial at each 4 corners 2 feet away from the main tree. The south, west corner is to help block elements and sun scald in the Canadian winters from the snow. After each guild is a 15 foot span with a couple raspberry bushes. The goal is to allow it all to spread in the 4 foot wide rows as it all wishes.
So I got plants on sale. I have gooseberry, aronia, and red and black currants. Looks like they all will grow to 5.5 to 6 feet tall and wide.
What would you do? Still put them 2 feet away from the center tree, or do I change the plan and place them 3 feet or even more away?