Main-Lining: Clone Tutorial

by Nugbuckets – Compiled and edited by Nebula Haze in August 2013


The act of training a marijuana plant to form a "hub" off a single node, creating a "manifold" for equal energy distribution from the roots to each cola.

The result is an even canopy and bigger yields with little extra effort.

An example of main-lining: Notice how nugbuckets has created a "hub" or "manifold" for even energy distributionExample of a flowering marijuana plant grown with main-lining

Main-lining was originally developed for growing marijuana plants from seed, but has been adapted to be used with marijuana clones.

Note: This article teaches how to use the "main-lining" technique on marijuana clones. This technique is slightly different when starting from seed.

Read the complete article on Main-Lining here:
(including starting from seed)


Notes by Nugbuckets: Main-Lining Marijuana Clones

I have found with clones that building a proper manifold adds an average of 10-21 days onto the total vegetative cycle. I average about 14 days to main-line clones.

The more you Main-Line, the more you will learn exactly when the plant is ready to be pruned and bonded. A grower must watch the plant very closely for her to tell you when she is ready to be pushed.

Newbie growers don't really have this down yet, and it translates into added veg time. Also, clones take longer than growing from seed. Period.

I highly recommend starting out with a marijuana plant from seed. They are genetically programmed to build a strong root mass out of the gate, (which is critical when it comes to how quickly the young plant will recover from main-lining / pruning / bonding)

During early vegatative growth, a clone is a bit more tempermental than a seedling.

Note: This article teaches how to use main-lining on marijuana clones. The technique is slightly different when starting from seed. Read the complete article on Main-Lining here (including starting from seed):

When main-lining clones, your goal is to create a central "hub" or manifold for your plant to distribute energy to each of the colas.

Your Goal When Main-Lining Clones

Main-lining with clones is not as neat as main-lining plants grown from seed. When using clones, your final main-lined trunk will look something like this.

Main-lined hub of marijuana clone
(this is what you're creating in this tutorial)
Main-lined hub of a marijuana clone

Main-Lined hub of another marijuana clone
(this clone was grown bigger, with 16 colas, so the hub is more "spread out")

Another example hub of Main-Lined Clone - by Nugbuckets

Step 1: Start With a Healthy Clone

Any clone will work, but symmetry is key.

You will get the best results using clones which were taken very early off the mother plant, when she is still growing in a symmetrical pattern.

These clones are still growing symmetrically, and are perfect candidates for main-lining. These clones will likely need to be topped in order to be main-lined.

These clones are still growing almost completely symmetrically

If clones are taken from an older mother plant, they are more likely to display an non-symetrical growing pattern (the sets of leaves don't grow exactly opposite from each other).

This makes it harder to main-line, because the central part of main-lining is allowing all colas to originate from a single node.

In the picture below, notice how the clone is not symmetrical. The growth is slightly lopsided, and the branches do not start at the exact same place on the trunk. This is a common growth pattern among clones taken from older mothers. Click the pic for a close-up!

Notice that the "branches" coming off the main trunk are not evenly spaced (click for closup)
(Click for closup)

This is typical behavior for clones, and you will have to compensate for this difference as explained in the steps below.

With clones, you have to look at it this way: when there is in an asymmetrical trunk, the top branch or "leader" will always be dominant over any of the node growth below it.

So when main-lining clones, it is mostly a matter of swaying the dominance away from the main cola until one of the chosen lower leaders catches up to it in vigor and stem diameter.

Fixing the asymmetry is done with a pretty radical pinch/bend/bond of the main.

Look at all bonding, pinching, and pruning as a form of suppression, and use that to your advantage.

How old and how tall should clones be when you start the main-lining process?

It depends on how fast your clones are growing. I started on this clone at day 10, when she was about 7.5 inches tall (picture of plant above with ruler).

It can be easy to get caught up with the details, but the most important thing to remember is that you are trying to fix an assymetrical axial branching pattern. You want to make things symmetrical again to equalize energy distribution.

The age of the clone doesn't matter nearly as much as starting with a healthy clone that has a few sets of leaves. Then the idea is to manipulate the plant so two main branches come off the main trunk. These branches should be as close together and symmetrical as possible, and you can use pinching and other gentle manipulation to try to even things out if you notice that one sides seems to be dominant over the other.

Here are the steps you need to follow.

Step 2: Top Clone (If Needed – Details Below)

Some nodes naturally grow with two main colas, like this clone right here. If that's the case, you can skip this step.

Skip this step if your clone looks like this
(already has two main colas/new growth tips)
This marijuana clone naturally has two colas, and does not need to be topped before main-lining

If you are starting with a clone that has grown out several nodes, like the one pictured below, you will need to choose which node you want to become your main hub.

Just choose any node with two healthy branches/new growth tips on either side which are relatively close together.

Then cut off everything above that growth (top the clone to your chosen node).

Leave the fan leaves directly underneath your new node. You will be cutting these off later, but she needs to keep leaves for extra energy right now.

Top clone for main-lining, if needed

Step 3: Correct Asymmetry in Your Clone with a Pinch/Bend (If Needed)

Because clones often do not grow with good symmetry, you will need to fix any non-symmetry so you have a hub that distributes energy evenly to all the colas.

If your clone is already growing with perfect symmetry, skip this step.

Take a look at the picture below of a clone which does not have perfect symmetry in the two main colas.

(not symmetrical)

Main-lining clone - first pinch to equalize energy distribution

Notice how on the clone's meristem, the left side is higher up and bigger. This means that this side is currently dominant. This dominance must be suppressed to equalize the hub and get the benefits of main-lining.

I use a light pinch and bend to equalize the two sides. Look at the first bend in the picture below; you may be able to see my fingernail marks from the pinch/bend.

Try not to tear or damage the cambium layer (the layer of inner bark) or allow the stem to split. Learn more about proper bending in this article about supercropping.

(pinch/bend to correct non-symmetry)

Closeup of first supercrop style pinch on a clone which will be main-lined

Any injury you create to a plant will take a bit of time to heal.

The more you break or tear your plant, the longer it will take to heal and get back into the swing of things, but even if you make a mistake, you'll usually be okay as long as you tape up your plants (and split them as needed for big injuries) and give them some time to recover.

You may also notice that that I left all the vegetation above the hub for now. A young clone like this needs all the energy she can get to continue building a substantial and healthy root system.

Remember: Clones often have weaker root systems compared to similarly sized plants grown from seeds. Therefore when main-lining clones, you must take extra care to reduce stress and give that root system time to develop.

Sneak peak: This is what the clone looks like after it's grown out after this step. Notice how the two branches are growing more evenly. That is the main point of the pinch/bend.

Marijuana clone manifold after recovering from the pinch / bend

In a few days, we will top or prune clone again for 4 total colas, and then clean up some of this extra vegetation once we can see she is growing vigorously.

Step 4: Tie Down Your Mains (Keeping Bends At The Same Level on Both Sides)

If your plant was damaged during any of the previous steps, or if you're worried she needs time to recover, you may want to wait a few days until your clone is growing out its two main colas.

This is a matter of expertise. As a beginner, it's better to err on the side of waiting too long. If you have a lot of experience training/bending clones, then you may be more aggressive.

If you're unsure, wait until you see that your clone is growing healthfully. At that point it's time to top or prune again.

I gave this clone a few days to grow out her two main colas before I started this step.

Just to give you an idea, this is what my clone looked like right before I tied her down.

Marijuana clone - in the process of being main-lined

Notice how I left all her extra vegetation. I will be removing this extra growth later, but I leave it on for now to help power the growing root mass.

Important: Tie Down Colas to Form 90 Degree Angle With Trunk & Keep Bends At The Same Level on Both Sides

You will want to use some slight bending/training/bondage to spread out your colas so they leave the main trunk at a 90 degree angle.

This cola is being gently bent and "spread out" to form a 90 degree angle from the trunk - this begins the classic main-lining shape

Make sure the bends are at the same level. This is very important! This picture of a different clone better shows off what I mean by trying to keep the bends at the same level:

When boding clones, make sure to keep the bends at the same level

You can use a variety of methods, including gardening wire, coat hangers, almost anything to tie down your plants.

Just avoid using anything too thin or sharp, like string, as it can cut into your plants. This type of training, where you tie down and manipulate the plant, is called LST (low stress training).

Here's a close-up of one of the types of ties I use to hold the plants down. It's just bendy gardening wire. You can also see the two growth tips at the end which will become two new colas.

A close-up of how I tie down my main-lined plants


Step 5: After Clone Has Recovered, Top or Prune To Produce 4 Colas (remove all growth tips except for 4 mains)

The point of this step is to remove all the growth tips except for 4 chosen mains.

I generally will do this 2-5 days after whatever training I've done until now. Sometimes your clone may need a little bit longer if she's growing slowly, if she had an injury, or if she didn't respond well to the training you've done so far.

The most important thing is to make sure that the plant is still growing happy and healthy before topping or pruning for 4.

Basically you want to make sure there are two main growing tips left at the end of each of your two main colas. You can either top the clone, or just choose two growth tips that are close together and remove all the other growth.

Topping produces more symmetrical growth, but adds extra time. I will usually chose 4 mains and use a pinch/bend to correct asymmetry because I am on a fast schedule. Any way you produce 4 symmetrical mains will work.

Don't prune unnecessary fan leaves yet! Just remove the growth tips besides your 4 mains. Make sure that each of your 4 main colas has a nice big fan leaf underneath to power the growth of those colas.

Remove all growing tips except 2 symmetrical growth tips on each side. Remove extra fan leaves and vegetation below the main splits. This picture will show you the 4 mains, and where the main splits are located.

A short animation showing exactly where to cut below the 4 main colas

Tie down your 4 new mains.

Your clone should now look like this

The clone after the vegetation has been cleaned up, leaving vegetation just at the ends of the 4 colas

Notice how I've taken all 4 colas and tried to spread them out.

In the best case scenario, you want to train this "hub" of your plant to have lots of right angles, while being as flat as possible, so all the colas will end up having lots of room between them to grow fat and get lots of light.

See how Nugbuckets ties down his main-lined plant

Here's a closeup of the wire ties I used to hold the 4 new main colas down. I bent thick copper wire into a hook and just hooked it gently around the 4 colas of the plant. You can use just about anything to tie the cola down as long as it's thick enough and doesn't cut into the plant. (For example, don't use string).

A closeup of how I tied down the colas while main-lining

You can see lots of new growth tips already on each main. In a few days, you will choose 2 of these to become 2 new colas, when you prune for 8.

Step 6: After Clone Has Recovered, Top or Prune Again For 8 Colas

I generally wait about 2 days after the last step. You may need to wait a little longer if it seems like your plant is struggling. If she's growing fast and healthy for a day or two, then you know she's ready to be topped or pruned again.

Here's what my clone looked like after being topped/pruned for 8:

Marijuana clone after being pruned for 8 colas - Clone Main-Lining Tutorial

In the picture above, you can see I trimmed each of the main colas so it only has two remaining growth tips. Sometimes it's easier to top, and sometimes you have two tips that you can manipulate into two new colas. The most important thng is to have 8 growth tips remaining, 2 on each of your previous 4 colas.

In this case, there were two suitable colas at the end of each main branch, and so I just needed to prune the growth below the two mains. When you can avoid topping the plant, it will save you a lot of time in the vegetative stage. However, when topping the plant, you tend to get more even growth without the need for a pinch/bend. It's up to you to decide exactly how you want to do it.

It's normal for plant growth to slow down a bit after being pruned or topped for 8 colas.

Step 7: Prune for 16, 32 Or More (If Desired)

If you would like to top or prune again for a total of 16 colas (or one more time after that for 32), then just make sure you give the plant enough time to pick her stride back up before each additional pruning.

This quick guide may help you decide:

Chart showing how many times to top your plant in total for your setup

You're Pretty Much Done! Now You Just Watch The Plant And Use LST and Supercropping to Keep Her Short If Any Colas Start Getting Too Tall.

All of your effort is worth it because you have built the perfect structure to power your plant's growth from now on. After this point, you pretty much just get to enjoy the fruits of your labor…

Here's this same clone 8 days later, so you can see what she looks like after she starts hitting her stride again. At this point, this clone is 23 days from rooting.

8 Days Later – Clone is now 23 Days From Root

Main-lined clone with 8 tops - 23 days from root

People often ask how tall? She's just under 10" in height.

How tall should a main-lined clone be? This ruler shows how tall mine way, just under 10 inches tall

Here's that same clone again 5 days later. I still haven't done anything but let her grow out. The main-lining is doing all the work for me to produce the desired growing pattern.

Main-lined clone - 8 colas - 28 days from root

Main-lined clone with 8 colas - Main-lining tutorial


Want more examples?

I'll main-line a different clone, and run her under the sun so you can watch her growth from beginning to end. Let's go!

Lets follow the life of this Ace clone through her early main-lining, then watch as she is bonded and pruned.

The first pic shows a young clone plant that has been pruned to hold two asymmetrical nodes. She was then allowed to stretch for a week or so. I've learned that giving clones some extra time to stretch out makes a big difference in how fast she recovers from main-lining.

This marijuana clone is ready to be main-lined - pic by Nugbuckets

First I cut away all the growth tips below the main nodes. You'll notice that I am less gentle with this clone than I was with the first one. I removed more vegetation at an earlier age.

At this point I have a lot of experience main-lining clones and I know she can handle it because she was given extra time to stretch initially. Only remove this much vegetation if you know she's got a strong healthy root system. If not, it's better to leave extra fan leaves on for now.

Main-lined clone after trimming - pic by Nugbuckets

Now the bonding begins… Our girl is the one in the middle. Notice the bends are all at the same level. This is very important!

When main-lining clones, think 90 degree angles. Try to make all bends at the same level.

She is then pruned for 4 mains, allowed to grow for a week or so

Marijuana clone is pruned for 4, then allowed to grow out - Nugbuckets

Then the marijuana clone is pruned for 8 mains….. allowed to grow a bit, then all the mains are bonded to the pot

Main-lining clones: Pruned for 8 mains, then bonded to the pot

She is re-potted into a 5 gal. bucket.

Main-lined clone is repotted in 5 gallon bucket - Nugbuckets

Then the clone is pruned for 16.

Main-lined clone is pruned for 16 mains

Here's what her main hub/manifold looks like at this point:

The Hub / Manifold of our Main-Lined Clone

A few days later…

Main-lined clone with 16 colas - Nugbuckets

At this point there's very little I have to do. Once the 16 colas are more grown out, I may need to bend/tie down parts of the plant to spread them out. Other than that, I pretty much let the plant do her thing.

The main-lining you've done so far will do the rest of the work for you as far as canopy management! Now you just tend to the plants and wait until harvest!


Topping vs Pruning: Cloning Question Answered By Nugbuckets

Question: What really peaked my interest with main-lining was the total plant growth through 1 node.

Now I can see plants from seed would work great, but with clones, do you still find that there is a difference in growth between the 2 sides?

I've got a couple of 2nd gen clones I'd like to mainline. #1 looks like a good candidate for this project, #2 has some nodal gap, will this one work??

#1 – top clone of plant grown from seed – less than a month since cutting
Symmetrical marijuana clone is perfect candidate for main-lining
I circled the node I was planning on building the hub off of

#2 – Top clone of a different plant grown from seed – less than a month since cutting – this girl has already been topped just to slow down her speedy growth.
This clone is growing with non-symmetrical nodes, but she still can be main-lined
Can I use the circled node even with this big space between nodes?

I topped above the node above the circled one, would I be better off using the current top node or the one I originally circled above?
Should I use the top node or the one I originally circled?


Answer by Nugbuckets

They all look good. You've definitely got the right idea.

With a clone, try to top near the tip where you have two nodes close together, then let those grow out a bit.

Those will become your two mains.

That way you dictate the stretch, or lack thereof, in the hub.


Continue to full article on main-lining:

Return to Top of Page