Firstly you don't need to do any training. You can get decent yields with little hassle.
But I suspect most of you will want to do this. A little effort in training (to get the right shape and flow) and the right defoliation (to get the right air flow and light penetration) can have huge impact on your harvest quality and quantity.
Training is techniques to bend or substantially alter the natural shape of the plant, and should be done during (early) vegetative stage. Defoliation is the process of removing undesired growth, and occurs sometimes as part of training, and can also be done in flowering to optimize yields.
Benefits of training and grooming your cannabis plants include:
- Reduce the amount of popcorn buds which are a hassle to trim
- Ensure the plant gets as much light as possible
- Send nutrients to the biggest buds
There are many methods for training your plant, and I'll cover a few below.
Layout & Arrangement
These are 2 concepts that are more about layout, and can be combined with the training concepts below.
Sea of Green - SOG
Not really training per se but a technique of placing plants to get a conistent canopy. It is done by growing many small plants in a compact area rather than focusing on a few larger plants. Tightly packing the plants in a causes the plants to grow together and create a canopy of buds, hence the name “sea of green”.
The only real training comes with their lighting, which is used to force flowering pretty early (week ~3) so that the flowering stage focuses on the main branches and not many auxiliary branches.
This expedited growing process allows for a greater yield in a much shorter harvest time.
Screen-of-Green (SCROG'ing)
Building on the goals of SOG, this method does not depend on lots of smaller plants, but instead uses a netting in which branches are woven into to spread the canopy of fewer plants (sometimes only 1!), with the same goal of filling an even and dense canopy of top buds.
The plants are trained around the netting, and cannot be easily re-arranged once they’ve started training themselves around the net,
This is why it’s recommended to only use this method with feminized seeds or clones from a known female plant and make sure each plant has at least 1 foot (0.3 m) between plants. You want to allow room for the plants to “bush out.” Screen of green is great for maximizing yields per the amount of plants, since it grows short, bushy marijuana plants.
Cropping, topping, FIM'ing, and bending
Outside of SOG which less volume of plants make up the big buds, most other methods involve encouraging the plant to distribute nutrients more evenly to more higher/taller branches.
Cropping
Cropping is the general term for removing unwanted bits of the plant. Could be top stems, a few leaves below, or entire branches depending on method. (See notes on supercropping below)
Topping
As the name suggests this cropping technique chops the plant just above a node (a node is the point where main trunk yields to lateral branches).
Topping is done just above a particular node, the upward growth stops, and the plant redirects all the energy into the 2 branches just below. This method allows us to avoid a single greedy cola bud, and feed many. Combined with mainlining or SCROGing give each new branch a great yield.
FIM'ing
F** I Missed! FIM'ing is topping at a slightly higher location that leaves enough of the new growth to continue growing the next node above, but stop the main trunk's growth. Instead of 2 tops you have 4.
Bending / LST
Low Stress Training is the use of string and clips to gently pull the branches, usually encouraging them to fan out more and give more space for growth and ventilation.
Mainlining (High Stress, Early Vegetative)
Mainlining uses multiple toppings and bending to create cola machines. It is considered HIGH stress training and extends the vegetative stage by several weeks. It is without a doubt my favorite method for results and ease of application.
Mainlining tops the plant early, right after 3rd node, and then continues 2-3 more times on the split growth. (First top gives 2 tops, which are then each topped for 4, and again for 8)
https://budtrainer.com/blogs/learntogrow/mainline
Defoliation
Removing leaves or growth from a plant to strategically influence growth. It's a bit contentious to some, rarely useful outdoors. But for indoor growers with limited space & light, proper defoliation makes a huge impact on yield.
Lollipop'ing
Specific method of defoliation, usually combined with mainlining or SCROGing this is aggressive cropping of all branches that reach less than half the plants height. Remaining branches are then stripped naked of all leaves and tertiary branches until the very top. Makes each remaining branch look like a lollipop, dig?
This really focuses flowering energy on the colas.
Super Cropping (High Stress - Late Vegetative/Early Flowering)
Supercropping sometimes called inner-cropping is arguably not cropping at all. Instead of cutting anything, we gently "break" the inner vascular structure without tearing the outer epidermis. This tells the plan it is under attack and to go into overdrive pulling up nutrients to "repair" itself. Since the process (when done right) does not significantly tear inner xlem/phloem, nutrients still flow.
The bent branches need support via ties or staking since supercropping breaks its support.
Hope that clarifies some of the terminology around growing and training your marijuana plants, let me know if you have questions or disagree with anything I wrote!