Leaf nodes stacking up on “Blue Dream.” Apples ripening in the background.
“My plants are starting to stack” or “my plants are stacking,” refers to the marijuana plants switching from vegetative growth into flowering phase as the days shorten. In vegetative growth, the leaves are huge and the internodes (the length of stalk between leaf nodes) are long. As the plants prepare to flower, leaf production slows and internode distance shortens, so the nodes where flowers emerge from are said to “stack up,” ultimately becoming the dense masses known as colas.