For the first planter tier, measure out your piece of timber and mark where the three pot plants will sit in the timber. Make sure they’re evenly spaced. According to our plans, we measured 190mm in from either end of of the timber. Draw a straight line between your marks, making sure this is in the middle of your timber. Then evenly space out some marks for your pots on the line and draw the holes, which in our case were 250mm in diameter.