Main-lining: an interesting grow method for bigger and better yields

Main-lining: an interesting grow method for bigger and better yields
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Adam Parsons

Main-lining is an excellent growing technique that results in large and uniform flowers. The expansive canopy created boosts airflow and light distribution, while lowering the risk of mold contamination.

The world of cannabis cultivation is ripe with innovation and progress. New methods and techniques are constantly being developed, with the goal of bigger and better yields at the forefront of the effort.

Main-lining, also known as fluxing, is a growing technique that has risen to popularity in recent years. The goal of main-lining is to produce the biggest possible yield, even in a relatively small space. This is achieved by manipulating plant growth using a combination of LST (low stress training) and topping.


Main-lining involves some serious manipulation and shaping of a plant during the vegetative phase. The primary objective of the growing technique is to train seedlings into developing a manifold, or Y-shaped stem.

This develops a center or “hub” for energy to be equally distributed from the roots to the buds. The rest of the entire plant is built up off this single node. This process is partially achieved by topping, and is repeated as newer growth forms during the vegetative phase of the grow cycle, doubling the number of main flower sites (colas) throughout this stage. This can be repeated as many times as the grower desires, on average forming anywhere from 4–32 colas. This all ready depends on the space available.

Speaking of space, this is one of the main advantages of main-lining; it’s highly adaptable and modular. Growers that only have access to a small closet space can still use the technique, electing to form a canopy featuring 4–8 colas. Growers with a large tent or outdoor space, however, can see plants through to their full potential, choosing to form up to 32 flowering sites.

So why choose main-lining out of all the other tried and tested growing methods out there? What makes this stick out above others?



First thing’s first, main-lining is really all about bigger yields. The formation of Y-shaped nodes during training leads to an even distribution of nutrients and energy all over the plant. This means that every cola is pretty much uniform in density, size, and appearance. There is very little chance of small popcorn nuggets forming; instead, all flowers form stunning pillars of high-grade, resinous flowers.

Because main-lining forms an expansive and even canopy, all bud sites are within a close distance to the light-source. This is another factor that lends towards uniformity in flowers. Such similarity within buds is highly beneficially for growers. For one, it makes canopy management much easier. Drying, curing, and processing also become faster and more simple. Equally-sized flowers will hold similar amounts of water and will dry and cure at the same speed, leaving less room for error.

An open and expansive canopy also means less risk of mold. Airflow is enhanced, which also boosts gas exchange in leaves.

Main-lining means growers get far more from the resources they pour into their plants. The same nutrients, water, and light can produce a much larger bounty as opposed to an untamed plant. Growers get far more bang for their buck when using methods such as main-lining.

Another advantage of this method is its ease. Compared to other growing techniques, main-lining is very low-maintenance. Once set up, it’s simply a matter of canopy maintenance. The end product is also more stunning than standard growing methods. The tall pillars of dank are impressive to friends, and more appealing to customers for those who sell their produce.


Just like everything in life, all of these advantages without any downsides would be too good to be true. However, the disadvantages certainly aren’t too negative, and are not enough to turn growers off from this reliable and trusty technique.

One downside of main-lining is the time it takes. It depends a bit on how extreme you want to go, as some like going as far as giving their plants funky shapes just fo the sake of it, but it can easily add an extra two or even more weeks to the overall grow cycle of a plant. This is because plants undergo stress during topping and low stress training and need extra time to recover and get back on track. 

Although not a big deal in the grand scheme of things, this could be a negative for commercial growers.

Because of the additional time it takes, main-lining is not compatible with autoflowering strains. Autos have very rapid grow cycles, and by the time the technique has been employed, half of their total development will be over. This could potentially harm overall yields.


How to do main-lining

Starting from seed, wait until your plant has formed at least 5 nodes. When formed, top the plant above the third node. Remove all of the growth tips below the third node. This will form the initial Y shape that is desired. Allow your plant a few days to recover from this imposed stress before moving on to the next step.

Your plant will now feature 2 main shoots. These should be tied down using suitable string or wire. This will direct the growth in a horizontal fashion. Exercise caution when tying down branches, being careful not to snap them. Be gentle.

After more growth occurs, you will end up with 4 main stems. This process can then be repeated as many times as the grower wants, resulting in bigger yields. Remember though, the more times your repeat the process, the longer the veg period will last.

As soon as you have produced the desired amount of separations, it’s just a matter of waiting for your uniform bud harvest to arrive. Regular light defoliation throughout the rest of the grow cycle will also ensure adequate light distribution, and will prevent plants from wasting energy on large fans leaves that aren’t necessarily needed. Remove these leaves when overcrowding starts to occur.

Adam Parsons
Adam Parsons

As a professional cannabis journalist, author, and copywriter, Adam has been writing about all things psychoactive, CBD, and everything in between for a long time. In an ever-changing market, Adam uses his BA (Hons) Multimedia Journalism degree to keep in stride with contemporary research and contributing worthwhile information to all of his projects.