Each Planter Well will irrigate 9" of soil beyond its edge, so one 24" Planter Well reservoir will keep the soil moist in a window box or planter that is 42" long.
Rules Of Thumb for the 24"L x 8"W x 3"H Planter Well Reservoir
Using One (1) Planter Well
24"-42" Interior Length x 8"-14" Interior Width x 8"-14" Interior Height.
Using Two (2) Planter Wells
51"-75" Interior Length x 8"-14" Interior Width x 8"-14" Interior Height.
Using Three (3) Planter Wells
78"-108" Interior Length x 8"-14" Interior Width x 8"-14" Interior Height.
