Node stacking is grower shorthand for short spacing between nodes. The internode, the length of stem between two nodes, is shaped by genetics, light intensity and spectrum, temperature (especially the day-night difference) and plant density. Tight stacking puts more bud sites per centimetre of stem, which helps produce long, solid colas.
In practice
Growers praise a cultivar for "stacking well" when its flowers join into one continuous cola in flower. To encourage tight nodes: enough light (low light makes plants reach), modest day-night temperature differences, adequate blue light in veg, and not crowding plants so they compete upwards. Internode spacing of about 2-5 cm (1-2 in) in veg is typical of compact plants; long-flowering, narrow-leaflet types often space wider.
Very dense colas can also hold more moisture inside, raising bud-rot risk in humid rooms.
Don't confuse with
- Stretch: a temporary increase in internode length after the flip.
- Foxtailing: new calyx spires growing on top of finished buds.
The length of stem between two adjacent nodes; short internodes mean compact plants and tight bud stacking, long ones mean stretch.Plant density is the number of plants per unit of canopy area; more plants raise yield per area up to a point but shorten veg and reduce uniformity.A bud site is a node where flowers form, where leaf meets stem, or a branch tip; training aims to put more of them in strong light.The dense, elongated cluster of flowers that forms at the end of a stem or branch; the main cola tops the leader.DIF is day temperature minus night temperature; a larger positive DIF lengthens stems, while zero or negative DIF tends to keep plants shorter.Blue light is the 400–500 nm band; it keeps plants compact with shorter internodes and thicker leaves, but a high blue fraction slightly lowers cannabis yield.The stretch is the rapid increase in height in the first two to three weeks after switching to flower, when many cultivars grow 1.5 to 3 times taller.Foxtailing is the growth of new, elongated calyx spires on top of existing buds; it can be genetic, or a stress response to excess heat or light.The point on a stem where a leaf (petiole) and its axillary bud attach; branches, flowers and clone roots all originate at nodes.
