How to mainline weed plants

If you want to increase your cannabis yields mainlining is a great plant training technique to master. By mainlining cannabis plants you maximize light absorption and increase the number of bud sites in one go while creating an even canopy structure, the result is bigger plants and loads more bud.

In this article, we break down the steps to get you mainlining like a pro. We’ll cover the optimal time to start, how to create the ‘manifold,’ and tips for maintaining your mainlined plants. We’ll even weigh the pros and cons so you can decide if it’s the right method for your grow. Stick around; your plants will thank you.

What does mainlining weed mean?

Mainlining is a cannabis training technique which is basically a combination of topping, ScrOG and LST training with the aim to create multiple main branches instead of one central cola. When you mainline a cannabis plant it forces it to grow more laterally and with a wide flat canopy structure. This shape provides better light distribution and contributes to a more uniform and bigger overall yield. It’s a bit more labor-intensive initially but pays off in the long run, especially if you’re looking to make the most of your growing space and resources.

Step by step how to mainline cannabis plants?

To mainline your cannabis plants successfully, follow these step-by-step instructions designed for maximum yield and efficiency. To begin: start with a healthy young plant, at least five to six internodes high.

First step: Top, trim and train

Cut off everything above the third node and trim away any leaves, shoots, and growth tips below the third node, leaving only two main branches. Don’t cut too close to the third node and leave a stub behind to avoid splitting. Then, gently train these branches to grow horizontally by applying LST techniques, allowing new shoots to form.

How to mainline cannabis plants - step 1

Second step: Perform a second topping and train

Let your plant grow without interruption until both of the branches reach their fourth internodes. Providing the plant is healthy and doesn’t show any signs of stress you can continue. Trim the tops, then gently tie the branches down.

You don’t have to strictly top above the 3rd node this time; you can choose to top above the 1st node/ branch. What’s crucial in mainlining is maintaining symmetry. So, if you decide to top at the 1st node on one side, make sure you do the same on the opposite side.

Also, at this step, for any branches that you decided to trim, you can just remove their growth tips but keep their leaves. (Instead of removing everything like in step 1). Keeping the leaves help the plant to stay strong.

How to mainline cannabis plants - step 2

Third step: Top again

Once each of the four branches now has grown beyond their third internodes, it’s time for the third topping. While the first topping required allowing the plant to grow well beyond the third node for root system development, at this stage, you can top the plants as soon as they are ready.

How to mainline cannabis plants - step 3

When should I start mainlining?

The perfect time to start mainlining marijuana plants is when your plant has reached at least five to six internodes, which is typically four to five weeks from germination for most strains. 

By this point your cannabis plants should be strong enough to handle the stress and recover from the initial topping and low stress training. Starting too early may cause stress before the plant is strong enough to handle it which could stunt growth. Although waiting too long could make the plant too unwieldy and reduce the effectiveness of the technique.

Does mainlining increase veg time?

Yes, mainlining will extend the vegetative stage of your cannabis plants. This is because by manipulating the plant’s growth with topping and training, you will cause mild stress and slow down its natural progress, however, the end result will be a big wide canopy with plenty of bud.

It should only add an extra one to two weeks to the vegetative stage. However when you consider how much more your plants will yield the added time is a well worth trade off for the benefits you’ll reap later. Just make sure to account for this extended veg time in your overall grow schedule, especially if you are growing outdoors.

What is the difference between mainlining and super cropping?

Mainlining and super cropping are both high stress training (HST) techniques with the goal of increasing the number of colas that the cannabis plant has. Mainlining focuses on creating a “manifold” by topping the plant early in its vegetative stage to encourage symmetrical growth and even bud distribution. The main aim here is to achieve a wide flat canopy, extra light distribution and improved nutrient flow.

On the other hand, super cropping involves intentionally damaging the plant by slightly bending and pinching its stems to make them knuckle like. Super Cropping does two things:
– By strategically damaging the stems, you can bend the plant into a structure that absorbs more light.
– The damage and stress that is caused stimulates the plant to produce more cannabinoids and terpenes as a defensive mechanism.

So, while they are both techniques mainlining aims for structure and symmetry, while super cropping focuses on shape and increasing cannabinoid production. Both techniques have their merits, but they target increasing yields in a slightly different way.

Mainlining vs topping

Mainlining and topping are two different techniques, although they share the same initial step of cutting the top off a young cannabis plant. However, the similarities mostly end there. Mainlining goes one step further than just topping and is a more advanced technique that involves creating a manifold for even growth and nutrient distribution. The goal is to create a balanced plant with equal energy distribution across all branches.

Topping cannabis on the other hand involves cutting the tip of the plant to encourage the growth of two new branches from that point. The main objective of topping is to prevent the plant from becoming too tall and to promote a wider bushier structure.

So although mainlining includes topping, it is a more planned approach that requires more time and attention but offers greater control over the plant’s final shape. Topping is quicker and less complicated but offers less control over the overall plant shape. Mainlining is a great technique but there is more that can go wrong, if you have done neither before I would recommend mastering topping first before moving onto mainlining your marijuana plants.

Mainlining vs manifolding

Mainlining and manifolding are terms often used interchangeably, but they are not entirely the same thing. Mainlining is a specific type of manifolding. Both aim to create a more symmetrical and balanced plant.

In mainlining, you’re essentially creating a “manifold” by training the plant to form a Y-shaped branch pattern right from the start. This involves precise cuts and sometimes the use of ties to guide growth.

Manifolding, on the other hand, is a broader term that refers to any technique designed to create a manifold or hub through which nutrients and energy are evenly distributed. It can include mainlining but also embraces other methods like fluxing.

So, if that wasn’t confusing enough, if you’re mainlining, you’re manifolding, but not all manifolding is mainlining. Your choice between the two will depend on how much effort and precision you’re willing to invest in your cannabis grow project.

Does mainlining weed plants increase yield?

Yes, mainlining will usually increase yield, but it’s not just about more buds. The technique promotes even growth and nutrient distribution, ensuring that all the buds receive adequate light and resources. When you master the art of mainlining you will be able to cultivate cannabis plants that have a uniform canopy, reducing the number of smaller, less potent “popcorn” buds, and concentrating growth energy into producing fewer, but larger and more potent colas.

However, be aware that this method also extends the vegetative phase, requiring more time and patience. The payoff is a more manageable plant that delivers a more consistent and potentially higher yield. So, if you’re looking for quality over quick turnaround, mainlining might be your go-to strategy.

Can you mainline autoflowers?

Mainlining autoflowers is possible, however is a high stress training technique so I would probably steer clear and stick with LST methods. Unlike photoperiod plants where you can choose to extend the vegetative stage by keeping them on an 18/6 light cycle, autoflowers have a shorter and predetermined vegetative stage which gives them less time to recover. If you are going to mainline autoflowers you will need to start the process as early as the plant can handle it, ideally right after the first few sets of true leaves appear.

Proceed with caution, as the stress from mainlining can potentially stunt growth if done incorrectly. The key is to be quick and precise to minimize stress and recovery time. If you’re up for a bit of a challenge and want a more uniform canopy in your autoflower grow, give mainlining a try.

What are the best strains for mainlining?

Mainlining can be done with pretty much any photoperiod, however, some are more suited than others. Ideally, go for strains known for their resilience to stress. Indica dominant strains usually fit the bill, as they are generally hardier and more forgiving than Sativas. However, some hybrid strains offer a good balance between vigor and ease of management.

When choosing a strain, also consider the flowering time. Strains with longer flowering periods give you more time to recover from any mistakes during the mainlining process. To get you started, popular strains for mainlining include Blue Dream, Girl Scout Cookies, and Gorilla Glue #4. Research and experiment to find the one that suits your specific needs.

Blue Dream



  • THC: 17-24%
  • Indoor Yield: 600 G/m2
  • CBD: 0.2%
  • Flowering: 8-10
  • Genetics: Blueberry x Haze
  • Terpenes: Limonene, Linalool, Myrcene


  • Berry
  • Fruity


  • Happy
  • Relaxed


  • Dry eye
  • Dry mouth
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Girl Scout Cookies


Mostly Sativa

  • THC: 22-25%
  • Indoor Yield: 400-500 g/m2
  • CBD: 0.74-1%
  • Flowering: 8-10 weeks
  • Genetics: Durban Poison x OG kush
  • Terpenes: Caryophyllene, Ocimene, Carene


  • Citrus
  • Fruity


  • Sleepy
  • Relaxed


  • Dry eye
  • Dry mouth
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Gorilla Glue #4



  • THC: 30-32%
  • Indoor Yield: 400 g/m²
  • CBD: 0.1 – 0.49%
  • Flowering: 8-10 weeks
  • Genetics: Chocolate Diesel x Chem Sis x Sour Dubb
  • Terpenes: Ocimene, Humulene, Pinene, Phellandrene


  • Coffee
  • Fruity


  • Happy
  • Relaxed


  • Dry eye
  • Dry mouth

You’ve got the scoop on mainlining weed plants! From understanding what it means, to step by step guides and strain recommendations, you’re now equipped to boost your yield like a pro. Go ahead, apply these insights to your next grow and experience the difference. Loving the content? Don’t forget to like and share this article. Happy growing!

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