# MISS'S-6 Citation General Planting Recommendations: T maximize the efficiency of the sub-irrigation system we recommend the following steps: 1) Start by adding a few inches of lightweight filler to the bottom of the planter. This is optional but offers 3 benefits: it reduces the amount-of potting mix required, it encourages faster root growth down into the troughs, and it will help decrease the overall weight of the planter making it sassier {0 move around.