Mainlining weed: How the pros get higher yields

Many cannabis growers want reliable ways to increase the yield and efficiency of their plants. Mainlining is a cannabis growing technique that increases yield. This article will describe what you need to know about this technique, including a step by step process, and answer many of your frequently asked questions. 

The goal of manifolding is to create a symmetrical plant that promotes equal distribution of energy and nutrients. Cannabis growers can use this technique as a cost-effective and user-friendly way to increase their cannabis yield.

By manipulating the length of the stems and bending them, growers can restrict the plant from growing one bud cluster, surrounded by smaller flowers, and instead promotes the development of multiple, evenly sized bud clusters.

The benefits of mainlining cannabis

The greatest benefit of mainlining is that it provides bigger yields. This technique also makes better, more efficient use of light, reduces the chances of bud rot, and reduces “popcorn” or larf buds. These types of buds use up plant energy and nutrients but do not yield harvestable cannabis. If they do yield, they tend to produce very little.

The benefits of mainlining cannabis
The benefits of mainlining cannabis

Using this technique also promotes colas that grow to the same height. Colas are the dense clusters of buds that grow tightly together. Having an even canopy is important because it helps make more efficient use of light and requires less tending. Once the initial training is completed, very little work is needed to maintain this growth pattern throughout the plant’s life.  

Download my free Grow Bible to learn more about mainlining and other growing techniques to maximize your yield!

Key terms to know

There is some divergence amongst growers regarding the differentiation between manifolding cannabis and mainlining marijuana. Some say the terms are interchangeable. Others explain that manifolds are topped two times, while mainlines are topped three times. Still, others indicate that mainlining refers to the growing technique, while the manifold is the actual structure that growers intend to create with the process.

Fluxing is another term that is often used interchangeably with manifolding. However, there is a small but important difference between these two techniques.

While manifolding cannabis creates symmetry that promotes even distribution of growth, energy, and nutrients, cannabis fluxing is used to ‘fill in’ small or oddly shaped spaces. In manifolding, the intent is for all colas to grow to the same size. This is not the goal when fluxing cannabis.

How to mainline: step by step

To mainline marijuana plants, it is recommended that you have a seedling plant, sterilized scissor or plant shears, and soft plant ties. Seedlings, not clones, are the best this technique, so make sure you start with high-quality seeds

1. Grow the seedling

Once the seedling has developed 5-6 nodes, mainlining can begin. Nodes grow directly across from each other. This spot is where the leaf or branch separates from the main stem.

Also read “Cannabis seedling stage

Waiting until at least 5-6 nodes have developed ensures the plant is hardy enough to begin topping and to provide good air circulation of the cannabis plant.

Mainlining Cannabis Grow the seedling
Mainlining Cannabis – Grow the seedling

You can start after this point; however, you’ll waste time and energy the longer you wait. Never start mainlining a cannabis plant that has already begun flowering

2. Top the plant

Once you have grown the base plant, it is time to top the plant. Using a sharp and sterile pair of scissors or gardening cutters, clip the main stem above the 3rd node with a clean, straight-across cut.

Topping stage 3 mainlining cannabis plants
Topping stage 3 mainlining cannabis plants

Be sure to leave at least 5 centimeters of space between your cut and the lateral branches. This will prevent the stalk from splitting later on. Stalk splitting damages the plant and may introduce disease. Remove the top growth for cloning later or disposal.  Now you will have one main stem and 2 branches directly across from each other. 

3. Trim undergrowth below 3rd node

Next, we need to restrict the plant’s energy production into the 2 branches of the third node that will form the ‘manifold’s main structure.’ Remove all vegetation from below the third node.

Mainlining Cannabis Trim undergrowth below 3rd node
Mainlining Cannabis – Trim undergrowth below 3rd node

This will strip the plant bare of all other energy intake means, leaving the plant with a bare main stem and the two branches of the third node. The plant can now quickly and evenly direct all energy and nutrients to the buds. 

4. Tie the shoots

Once the emerging branches are strong enough, gently tie them down to create a 90-degree angle. This trains the plant shoots to grow horizontally to create the manifold. It may be prudent to allow the plant to recover or grow long enough for a few days before tying the shoots down.

Tying the shoots of a marijuana plant
Tying the shoots of a marijuana plant

If you don’t have plant-specific tie material, be sure to use a tie or wire that will not break cut through your plant. Coat hangers or pipe cleaners are one option but avoid fragile wire or string. 

5. Wait for growth

Leave your plant to grow for several weeks. Each stalk will grow and develop new nodes during this time. Some growers wait until each main has grown 3- 4 new nodes; others complete the topping process as soon as they see new growth tips. 

6. Top again

Choose a new set of nodes on each main to top. The nodes selected must be in the same place on both sides of the two mains and have symmetrical nodes (directly across from each other).

This helps create manifold cannabis and provides the plant with an efficient and equal distribution of nutrients. If possible, select nodes that also have similar growth on both sides. Once each side of the plant is topped above the chosen nodes, remove all growth tips below.

Some growers chose to remove all of the fan leaves; others prefer to leave them because they help with energy. Either way, you should have 4 mains or colas. 

7. Tie again

Once the new mains are long enough, tie them down as you did in the previous steps.

8. Repeat steps 6-7 until the desired manifold is created

Each time you top the plant, you will double its colas or mains the plant has. Most indoor growers stop at 8 colas. However outdoor growers can develop up to 32 colas and still yield high-quality weed.

The more colas you have, the more the plant’s energy is distributed among the buds, creating lower quality weed. That’s why you should grow outdoors if you want the most colas. Once the plant shape is fully formed, you may remove ties. 

Mainlining Cannabis Creating the desired manifold
Mainlining Cannabis – Creating the desired manifold

Now that the manifold is created, you can simply grow your plant just like you would normally.  If you notice one cola growing taller than the others, you can gently pull or bend it down and away from the center of the plant, using a soft tie again as needed. This helps ensure the canopy of the plant is even. 

Other methods that increase yield

Super-cropping is another technique that many growers use to increase their crop yield. This is arguably one of the most popular growing techniques and is very different from manifolding.

Aside from technique, growers also have strategies such as increasing light intensity, providing the right balance of plant nutrients, controlling temperature and humidity, and harvesting during the proper window to try. 

While growing techniques increase your chances for higher yields, you’ll also need to start with the best seeds! Shop high-quality seeds from my seed bank.

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Other pruning methods

Besides mainlining, there are more techniques to prune your plants for more yield. Find a short explanation in my pruning article, or head directly to a technique below:

FAQ about mainlining marijuana

What are the best strains for mainlining?

Strains that grow medium to tall colas are ideal for mainlining. Some examples of excellent marijuana strains for mainlining include Gorilla Glue, Jack Herer, and Cannatonic.

How long does mainlining weed take?

On average, the growth time for mainlining is about 60 to 70 days. However, this depends on the number of toppings and the amount of time between them.

Can you mainline auto flowers?

Autoflowering cannabis strains should not be mainlined.  These strains grow faster than others and will be stressed by frequent topping, impacting final yields.

Should new growers try to mainline cannabis?

Yes! Mainlining is a great technique for beginners or new growers. It requires no special skills and will yield dense, abundant buds with most healthy plants. 

Learning to grow marijuana like a pro takes practice and learning. Get all the growing info you need from our blog.

Have you tried mainlining marijuana plants? What’s your favorite growing technique? Tell us in the comments below.

Happy growing!


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Robert Bergman


Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations ... See profile

3 comments on “Mainlining weed: How the pros get higher yields”

  1. Hi, I’m a newbie and I found yours site amazing. Could I ask you about the right time to swap on flowering stage using the main lining? I mean, I thougtht some days after the third topping ( for 8 colas) . Is it correct ? Thanks in advance.

  2. I plan to do this my next grow with ILGM Purple Haze. It will be my fourth grow but first time to try this. Thank you for the inspiring article!