Unstack the tower and lay the pots side-by-side for preparation. Turn each pot on its side and secure the 1-inch support bars, which enable the stacking action, in their assigned holes. Place the pots right-side-up, balanced on their supports, for planting.
Mix quick-draining potting soil and organic compost in equal parts in a bucket, and add 6-24-24 granular fertilizer to the mix. This foundation provides drainage, moisture retention and long-term nutrition for strawberry growth, and will support the plants through the growing season.
Fill each pot three-fourths full of this mixture, and spread the soil to present an even planting surface. Plant one strawberry plant per opening in the tower pot, for a total of six plants per pot. Plant the strawberry seedlings so that their crowns sit at soil surface; these plants fail with deep or shallow plantings.
Move the pots to a place where they get full sunshine for eight hours a day, for best blooming and fruiting. Put them in a spot where they get good air movement, but avoid windy, unstable locations. Heavy winds may knock your tower over.
Stack the pots. Put the support bars on the bottom of one pot into the manufacturer-drilled holes in the lip of another pot, and press down firmly to secure. Repeat as necessary. Stack all the pots you have in one stack, or build multiple shorter towers for better security.
Fill each pot to the brim with water and allow it to soak in, to water the seedlings. Repeat this watering every four to five days to keep the soil consistently moist. Strawberries don't do well with dry soil.