Question 549001
this is much easier to solve by drawing it

my attempt is below
best to do this on graph paper or excel spreadsheet
outline rectangle 14 boxes accross and 10 boxes down each box is 1' by 1'
start with putting seed pot in upper left corner skip 3 boxes put another seed skip 3 boxes and so on
0=seeds []=empty foot square
|0[ ][ ][ ] 0[ ][ ][ ] 0[ ][ ][ ] 0 [ ]
[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]
[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]
[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]
|0[ ][ ][ ] 0[ ][ ][ ] 0[ ][ ][ ] 0 [ ]
[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]
[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]
[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]
|0[ ][ ][ ] 0[ ][ ][ ] 0[ ][ ][ ] 0 [ ]
[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]

mine came out with a foot left over between 2 sides and the plants so basically if we were to shift the whole set of seeds diagonally down to the right a bit we could make an even 6 inch space between the pots and the sides of the walls
hopefully the above diagram helps you see it enough to draw your own