mainline cannabis

How To Perform The MainLining Technique

If you’ve heard of mainlining before, but have no idea how it works, or how it benefits your cannabis plants, then keep reading. We’ve covered everything you need to know about this bud-boosting growing technique.

Everything you need to know about mainlining cannabis


Whether you’re new to growing cannabis, or an old hand trying to learn new tricks, mainlining is an essential technique you need to know about. Mainlining cannabis plants not only boosts yields, but allows you to carefully shape plants—perfect for when space is tight.

And the best part? Once you know how to create a manifold, mainlining is incredibly straightforward, making it ideal no matter your experience growing cannabis.

Manifold and Mainlining: What Do They Mean?

Let’s start at the beginning and break down exactly what we mean when we’re talking about mainlining and manifolds. In practical terms, the technique is a hybrid of LST, topping and a ScrOG net.

  • Mainlining refers to a training technique growers use to encourage the development of several large, uniform colas—not just one.
  • The manifold is how we achieve this, by splitting the cannabis stem and creating a Y-shaped hub. Doing so diverts nutrients and resources to several branches.

The technique is not only straightforward, but requires little extra effort. As long as you know how and when to mainline cannabis plants, you can do it in minutes. And, once you’ve created your central manifold, you can replicate the process on newer growths, essentially doubling the number of colas every time. Why have one central cola when you could have 4, 8, 12, 16 or even 32?!

Are There Benefits to Mainlining Cannabis?

The most significant advantage of mainlining cannabis, of course, is the potential increase in yields. Rather than several smaller popcorn buds draining energy away from the central cola, we have dozens of branches loaded with dense, uniform colas.

Other benefits to mainlining include:

  • Increased canopy size
  • Easy to implement
  • Gives greater control over stretching
  • Adoptable indoors and outdoors
  • Grow several cannabis plants, even if space is limited
  • Only needs to be done once

Because mainlining takes place in the early stages of cannabis growing, it only needs to be done once or twice before you start seeing the benefits. Get your plants under control from the get-go, and all you’ll need to do is sit back and wait till harvest.

How to Mainline Cannabis Plants

If you’re sold on the idea of mainlining, then it’s time to jump straight into our step-by-step guide. You won’t need much equipment, but you should make sure plants are healthy and robust beforehand.


This is one of the more minimal processes you’ll carry out when growing cannabis. Really, all you need are some pruning shears and plant/cable ties!

Creating a manifold

Tha manifold is the central structure of the mainlining process. We’ll go through the process of creating a manifold, then explain how you can utilise it several times throughout the vegetative phase.

Step 1

Wait until your seedlings have developed between 5 and 8 nodes. It’s essential not to top seedlings too early—otherwise, they may not recover. Then, cut the entire plant down to the 3rd node (3rd pair of leaves from the base).

Step 2

Remove all additional growths and vegetation below the 3rd node. Your plant should have a central stem with two large fan leaves branching from the very top (Y-shape).

Step 3

With your two main shoots prepared, it’s time to tie them down—gently! Young cannabis plants are fragile, and it’s easy to snap new growths. The aim is to train shoots horizontally, parallel to the ground.

Secure the other end of your plant ties or cable ties to the edge of your container to keep shoots on the straight and narrow.


If performed correctly, cannabis plants should start to recover almost immediately. And, with the central manifold created, the roots will now split nutrients and other essential resources between the two shoots at the third node. If you want to maximise yields, we recommend creating at least eight colas.

With your knowledge on manifolds established, it’s time to learn how to go about mainlining.

Step 1

Wait until each branch of your manifold has grown four new pairs of leaves. Then, similar to before, top either side down to the 3rd node.

Step 2

This time, however, you aren’t going to remove all of the growth below the third node. Instead, only remove the second node, leaving node one and three intact.

Step 3

Repeat the process on the other side, and you should have eight shoots in total (two pairs of leaves on both of the main branches).

Step 4

Uniformity is key to keeping plants under control, so ensure you adjust the ties to keep both central branches tied down, and the base of the newly created shoots parallel with the ground.

You want your newer stems to grow to the same height, so check back twice a week and adjust accordingly.

Step 5

With your plant topped and tied down, it’s merely a case of fulfilling their needs with water, nutrients and light while waiting for them to grow. Once you’re happy with the height (will vary based on your tent, grow op etc.), flip them to flowering by changing the light schedule to 12/12.

Step 6

If you’ve followed all the steps outlined above, well done! You’ve successfully mainlined your plants, and in a few weeks, you should have eight dense colas to harvest and enjoy. During flowering, you can continue to prune and manage plants as you normally would.

Cannabis Mainlining Hints and Tips

  • Trim fan leaves right before flowering: Although this is more of a general tip, it’s just as crucial with mainlining to trim excess fan leaves, either just before flowering or within the first two weeks of the flowering phase. Doing so ensures each of your newly created colas receives maximum exposure.
  • Don’t start mainlining unless plants are healthy: Mainlining is incredibly straightforward, but we cannot stress how important it is you only start topping and training plants if they are healthy.
  • Check plants twice a week to maintain their shape: During the vegetative stage you’d be surprised how quickly plants will grow and stretch. Mainlining relies on a principle of symmetry, so you should check plants twice a week and adjust ties accordingly.
  • Seeds are more receptive to mainlining than clones: Cannabis seeds will naturally develop symmetrical nodes, which makes creating a uniform manifold significantly easier. You’ll have to use your own judgment when mainlining clones.
  • Don’t tie down branches too tightly: You must find a balance between maintaining the symmetry of mainlining and letting branches develop naturally. Gentle plant ties are preferable to cable ties, as the latter can damage young branches and shoots.
  • Mainlining works with hydroponic setups: Yes, you can mainline cannabis plants grown with hydroponics. You’ll need to be careful how you tie them down though as the plant won’t be anchored directly in soil, but otherwise, it’s just as effective!

Do You Need a Net to Mainline Cannabis Plants?

Unlike ScroG, mainlining doesn’t use a net. By topping plants early, and creating a manifold, each branch will be significantly tougher than usual. If you’ve ever looked at the stem of an untrained cannabis plant, you’ll notice how much thicker it is than any other branch. With mainlining, you’re forcing the plant to duplicate that same thickness and toughness across multiple stems, not just one.

The point of a net in ScroG is to support existing branches, and help even out light distribution. However, by training plants to develop several colas, and encouraging stronger branches, your cannabis plants will do an excellent job of supporting themselves, without a net.

The only time you may need to brace mainlined plants is during flowering. With supersized colas, even tougher branches have a hard time bearing their weight.

Mainlining vs Super Cropping vs LST

It’s common for growers to adopt multiple techniques when growing cannabis. However, mainlining is more of an “all-in” approach. By that we mean you’ll be topping and manipulating your plants stem structure in such a way that you shouldn’t need to use additional training or topping techniques.

Super cropping

Super cropping is a way of shaping plants that you haven’t mainlined, and while it’s a favourite among many growers, it’s also very labour intensive. Compared to super cropping, mainlining is simple, can be done in minutes, and needs very little intervention from the grower once you’ve established the manifolds.

Mainlining already adopts the principles of LST, so it’s not about choosing one over the other. If space in your grow tent is tight, then stick to mainlining. If you have room to play with, practise LST and see what the results are. LST doesn’t involve as much aggressive topping, making it popular among beginner or unconfident growers.

Should You Try Mainlining?

Mainlining is a simple, inexpensive, and non-labour-intensive technique that can improve yields. When you weigh up the benefits against the cons (there aren’t really any), it’s hard to think of reasons not to mainline cannabis plants.

There are, however, a few exceptions. Autoflowers, for example, shouldn’t be mainlined. Autoflowering cannabis strains grow faster than any other, so any stress caused by topping will only impact the final yields. Mainlining, generally, is also better suited to medium or tall sized strains, as you will struggle to see the benefits on dwarf varieties.

Overall, mainlining is a near-perfect training technique that, in the majority of situations, is going to help your cannabis plants reach their full potential. And, if nothing else, the sight of eight engorged colas never gets old.

Click the link to find out what mainlining is, how the growing technique works, and how mainlining cannabis plants can significantly boost yields.

How to Main-Line Cannabis

Published : Apr 16, 2019
Categories : Cannabis cultivation

Who doesn’t want bigger, denser buds and a faster trim? If you main-line your cannabis plants, that’s what you’ll get in addition to a bigger overall yield. This training method takes a bit more upfront work than other techniques, but it’s not difficult to do. Read this guide to learn how to main-line and why it works.

The main-lining technique is an advanced training method that encourages your plants to form an even canopy for uniform colas and maximum light penetration. If everything works to plan, the extra upfront work will translate into a substantially bigger yield by the time you reach harvest.


Main-lining cannabis plants creates a manifold system using the stems and branches of your plant. A manifold has one inlet and multiple outlets. Think of it like a splitter for a TV signal.

The main trunk of your plant forms the inlet. You will create the outlets as you top the plant to create more branches. Then, using multiple types of training methods, including bending and tying the plant, you’ll form the plant into a symmetrical network of colas with an even canopy, so that each top has uniform growth and bud development. When done correctly, there will be little, if any, popcorn buds.

Main-lining will give you results as good as ScrOG (Screen Of Green), but without nearly as much effort. You do all the prep work early in veg and only make minor adjustments as the plant grows. Eliminating the nets has significant advantages too. It’s much easier to water and flush your plants—or just move them around if you need to.



– Cannabis seeds
– Clean razor
– Plant-safe wire or ties
– Plant cage

We recommend that you grow from seed if you want to try main-lining. It’s possible to main-line clones, but it’s harder to get the symmetrical nodes this technique requires. As plants become more mature, they naturally create asymmetrical nodes, and clones are always at the same level of maturity as the mother at the time when the cuts are taken.

You can make your own plant cage from heavy wire or modify one from a garden shop. They’re commonly used to support tomatoes and other high-yielding vegetable and flower plants. For main-lining, you’ll only use the bottom ring and the support legs.



Start your seeds using your preferred method. Allow them to grow until they have at least 5 nodes, then transplant into their final pot.


Top your plant at the 3rd node. Make a straight cut and don’t FIM. Remove all vegetation above and below the 3rd node. Leave the 3rd set of growth tips and leaves intact.

You’ll now have the main shoot (the manifold intake), two branches and enough leaves to generate energy for your plant so it will continue to grow. The two branches, or growth tips, will form the main pipes into the manifold.

Gently bend the two branches down on opposite sides of the plant until they form at least a 90° angle and tie them down. If they’re not long enough to tie down, allow them to grow for a couple of extra days first. They can be tied or clipped to the main stem or to the side of the pot. The support ring will be too tall to use at this point.

Make sure that the material you use to tie down the young mains does not break their skin. If you don’t have ties or wire designed to support plants, use a heavier gauge wire. Coat hangers or pipe cleaners will work, but avoid very thin wire or string.

Don’t be alarmed if it looks like you’ve stripped your plant of almost all its vegetation. It’s supposed to look like that and the plant will recover quickly now that it is directing all its energy to the single set of growth tips that remain.


As each main recovers, it will reach towards the light. The stem will lengthen and new leaves will grow. If left at this point, the plant would have two colas, but each one would fight for dominance. One would probably win and be visibly bigger than the other, and you’d still have weak lower branches with larfy popcorn—exactly what we’re trying to avoid.

New nodes should be growing on each of the two existing mains in mirror-image fashion. Choose a matching pair on each side, making sure they’re spaced an equal distance from the plant’s trunk.

Top each node on both mains leaving the growth tips intact. Keep the fan leaves directly below each growth tip, but remove all other vegetation below them, all the way down to the plant’s trunk. This funnels all the plant’s energy to the four mains.

Once the new mains are long enough, tie them down like you did with the original two.


If four mains, meaning four colas, are enough, you can stop here. If you’d like more, repeat step 3 until you’re satisfied with the number.

Each time, top all of the current mains at nodes that are the same distance from the trunk, so that everything is uniform. That means that you’ll double the number of mains each time going from 4 to 8 to 16 to 32 to 64.

Most indoor growers stop at 8 colas and outdoor growers top to 16 or 32 tips. If you’d like to combine main-lining with ScrOG, 32 to 64 mains should be your goal.

Main-lining will increase the overall yield compared to many other training techniques, but don’t go overboard. At some point, you’ll reach the maximum capacity of your growing environment and your genetics. When you go past the point where you can increase the total weight, you’ll only distribute it across more colas and end up with smaller buds.


After you finish making new mains, give the plant time to recover. Once each main is growing toward the light, install the cage and tie each main to the ring. This will give your plant a uniform shape and allow the light to penetrate through the canopy so that the top buds don’t put the lower ones in too much shade.

At this point, most of the work is done, but you still need to watch the main stems in case one shows a dominant growth pattern. If that happens, gently bend it or tie it down until the tip is slightly lower than the next tallest cola. Sometimes, you can slide the wire attaching the cola to the ring, so that it’s at an angle that makes it shorter.


Once the manifold is established, the stems will get woody enough that they retain their shape, so the initial tie-downs will no longer be needed. Remove them so they don’t cause any damage as the plant grows.


The majority of your work is now over, so you’ll be able to relax, feed your plants and enjoy the show as they start to bloom. If you’ve main-lined properly, you’ll be more than satisfied with both the final yield and overall bud density.

As a bonus, main-lined buds have a high calyx to leaf ratio, so they’re really easy to trim, cutting down the time to manicure by as much as 75% in some cases.


Main-lining works in ways that are clear to see. The even canopy lets plenty of light reach even the lower buds so that shade is minimized, but there’s another reason why main-lining delivers optimal results.

Cannabis plants that tend to have a single, large cola do so because of a trait called apical dominance. The plant naturally favours the cola that’s closest to the light and sends the majority of its nutrients to that branch. If something happens to that branch, the plant redirects its energy to the next tallest one. The shift is made by adjusting the plant’s hormonal balance.

Because main-lining seeks to keep all the main tips at the same height, it artificially controls the hormonal balance and avoids apical dominance. As a result, each cola receives the same amount of water, nutrients and light for even growth and bigger yields.

This control is easier when all stems branch out from the plant’s main trunk at the same point. Nugbuckets, the grower who pioneered the main-lining training method, found that as much as an inch difference in the height of the initial branching made a huge difference in growth patterns. That’s why main-lining yields more than other training methods.


If you want bigger yields, denser buds and easier trims, try main-lining your cannabis plants. This technique is somewhat advanced, but easy enough for practically any grower to use. By managing stem height with a combination of topping and tie downs, main-lining controls apical dominance for even energy distribution

Main-lining cannabis is a rather simple training method that controls apical domiance for even canopies, bigger yields and denser buds.