What are nodes and internodes of cannabis plants?
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Cannabis, like many other plants, develops nodes and internodes during its growth cycle, which play an important role in understanding your plant's overall health and are central to manipulating in a way that suites your grow environment or produces the best results.
All plant stems are linked by nodes and internodes. Nodes are the parts in a plant that connect new stem offshoots with older growth, which can take the form a branch, a leaf, or even a bud.
On a cannabis plant, for example, the nodes on the main stem are the areas where the newer branches separate from the main stem of the plant. They are also the area where flowers grow.
The node directly below the main flower of a cannabis plant (sometimes called the “crown”) is called the apical meristem.
Internodes, on the other hand, are the sections of stem/branch between two nodes. Cannabis strains that are known for stretching generally have longer internodes than other varieties.
WHY ARE THEY IMPORTANT?
The nodes and internodes can tell you a lot about the gender of your plants and whether they are exposed to the right temperatures or amounts of light. They also play an important role in pruning and cloning.
If you’re unsure about whether a plant is male or female, take a closer look at its nodes.
Plants generally begin to form flowers within 3 to 6 weeks into their vegetative phase. These flowers form in the nodes along the meristem (central stem) of the plant and other branches and take on one of two distinct forms.
Flowers with long, white pistillate hairs are signs of a female plant. Small, closed buds, on the other hand, are signs of male plants.
TEMPERATURE OR LIGHTING
Finally, the spacing and size of the nodes and internodes of your plants can tell you whether you need to adjust the temperature or lighting in your grow area.
If you notice that the internodes of your plants are growing too long/short, it may be a sign that they are experiencing too large of a temperature change at night.
Warm nights and cold days tend to shorten internodal distances. On the other hand, warm days and colder nights may cause internodes to grow larger.
Unusually long internodes may also be a sign of plant stretching. This happens when plants do not get enough light and reach out in search of the nearest lights source.
Long internodes are problematic as they may develop into weak branches that, at flowering time, may break under the weight of a plant’s buds. Shorter internodes will ensure your branches are strong enough to sustain the weight of your plant’s flowers as you approach harvest time.
Nodes and internodes are also important when pruning season comes around.
Roughly 2 to 3 weeks into the vegetative cycle, inspect your plants and make sure they have several large internodes before you begin pruning.
There are various ways to prune cannabis plants, and most of them require you to cut your plants at specific nodes.
Topping, for example, requires you to cut the meristem of the plant slightly above a node with thick, strong branches. This allows encourages your meristem to create two separate branches that eventually develop large coronas (or crowns).
Alternatively, some pruning techniques encourage you prune your meristem so as to leave behind only 4 main branches. This will concentrate growth in these areas and help to develop thick, dense buds alongs those branches.
Some growers also swear by simply pruning the branch tips to encourage higher growth rates in the shoots just below the cut.
Whichever pruning technique you prefer, nodes and internodes are vital for understanding where to make the right cuts to encourage your plant to grow and develop effectively.
Cloning allows you to preserve a specific plant phenotype for years to come, which is great if you happen to grow a plant that demonstrates exceptional traits.
Clones are usually cut from lower parts of the plant as they produce stronger, healthier cuttings. Most growers take their cuttings from branches at least three nodes from the top cluster of a plant to ensure the optimal health of their clones.
To take a clone from a mother plant, its common to cut a branch just above a node.