What is Cannabis Trellising and How Do You Do It?

Every cannabis grower wants the best yields from their plant. 

He carefully chooses plants with solid genetics and does everything necessary to encourage the plant to grow well. In addition, he uses many training techniques to boost yields. 

But is it a good idea to use several training techniques, or is it best to stick to one that works for you?

The answer to that question will depend on your experience. In addition, experimenting with various methods will give you an idea of what you can expect. 

One of the most famous methods for even tomato gardeners is to use a trellis. Similarly, cannabis growers use a ScrOG, which is nothing but a horizontal trellising method. 

But, you can experiment with vertical trellising as well, just like growing tomatoes. 

So, what is cannabis trellising, and how do you do it? Is it an excellent way to increase yields?

In this guide, we show you everything you need to know about cannabis trellising. Outdoors, indoors — no matter where you grow, you’ll be able to set up a great trellis at the end of the day. We have a detailed step-by-step guide at the end of this article to set up a trellis both indoors and outdoors. Make sure you check it out!

What is Cannabis Trellising?

As a technique of growing plants, trellising goes all the way back to the Roman Empire. At the time, they used this method to grow plants vertically. But, since then, it has even given way to an architectural style and art form. 

Over time, trellising has evolved into an advanced technique. It is a method that uses a structure to support the plant’s growth and organize the canopy. The trellising system consists of a frame built around the plant and a square net draped over it. 

The net acts as a supporting guide for the branches, growing evenly and getting more exposure to air and light. 

You can use trellising to grow cannabis in two ways — vertical and horizontal. 

In vertical trellising, tall mesh frames are installed around the plant to support the branches vertically. This is mostly preferred for outdoor plants.

On the other hand, you can use a horizontal trellis to grow a screen of the canopy on the top — where all the branches get equal exposure to light and air in an indoor environment. This increased exposure leads to better, bigger buds. In other words, it’s called ScrOG. 

How Can Trellising Cannabis Help?

You can't see the trellis here clearly, but this grow journal by Soosan shown in the image above proves how you can get massive yields from cannabis trellising aka ScrOG.  

Cannabis, being a weed plant, has vigorous growth. If you let it grow naturally, all the branches grow towards the sun, like an inverted cone. This bundling of branches can leave the canopy with inadequate light, air, and space, leading to smaller buds.

Think of a Christmas tree. Only the branches at the top receive all the light, whereas those at the bottom are ignored. Similarly, cannabis plants have the same structure, but you can train them to grow differently. 

So, trellising organizes and directs the plant’s branches, so they don’t bundle up together and grow evenly. Essentially, it lets the plant know where to grow. 

Trellising provides ample space, light, and airflow to your cannabis plant so it can grow bigger buds and prevent bud rot or mold. Plus, it offers support to bigger buds or branches that may otherwise break under their own weight.

Training Techniques to Complement Trellising Cannabis

Although trellising produces good yields on its own, you can increase the chances of a massive harvest by complementing it with other techniques. Here are a few methods that work best with trellising:

Topping/FIMming

Both Topping and FIMming will work very well with cannabis trellising. Essentially, both the methods are the same with slight differences. For example, Topping involves cutting the tips of the plant using sharp scissors. FIMming, on the other hand, requires you to pinch off the tips with your hands. One difference between the two techniques is that while Topping demands that you cut the entire tip, FIMming allows you to remove only 70 to 75% of the tip. As a result, FIMming is slightly less stressful for the plants, but both techniques produce pretty much the same results.

The main reason you Top or Fim is to increase the number of colas the plant produces. Typically, cannabis plants develop one main cola or bud that towers over the rest of the buds. But, once you Top or Fim the tips, they divide into several colas.

You can start Topping when the plant is in the vegetative stage with at least 4 to 5 nodes. Note that the plant may still be small and fragile at that point. Once you Top the plants, you'll notice new growth next to the nodes in just a few days. 

The main cola separates into two different colas. You can wait for a few more days until you can Top the new growth again. Naturally, the two colas will produce four more colas. It's best to stop at this point because you're essentially dividing the main cola into several parts. Going any further will limit the yields severely.

LST

Also known as Low-Stress Training, it is one of the best techniques to improve yields. Essentially, LST involves bending the plant's branches to the sides of the container to distribute light equally. You can use zip ties or soft wires for this process, but make sure they don't cut into the plant.

Like Topping, you can start LST when the plants are small. Be gentle and ensure you don't break off the stems when bending them. Again, remember that damaging young plants will negatively affect the yields, so use soft garden ties that don't harm the plants.

LST gives you more yields and allows you to use lights efficiently. For example, plants that don't undergo LST produce many popcorn buds. Popcorn buds are buds found at the bottom of the plant. Due to lack of light, they struggle to survive and ultimately end up small. On the other hand, LST allows you to distribute the light to every part of the plant.

It's best to start Topping and then experiment with LST, so the new colas get ample light. However, even if you don't Top the plants, the very act of bending the branches to the side will provide more light to the branches at the bottom, leading to better yields. If you still notice many popcorn buds, you can get rid of them, so the plant focuses exclusively on the main colas to produce bigger buds. 

Another advantage of LST is that it suits growers that don't have a lot of vertical space. Cannabis plants tend to grow twice their size during the flowering phase, so increasing the headspace in the grow room becomes challenging after a point. Thus, instead of increasing the vertical height, you can limit the plants to a specific height by employing the LST technique.

Lolllipopping

Lolllipopping is another technique that complements cannabis trellising. Essentially, Lollipopping is a High-Stress Training technique (HST) that involves removing the bottom parts of the plant so that the plant focuses all its energy on its bud sides located at the top. 

The trick to getting massive yields with lollipopping is to do it at the right time. Almost every training technique needs to be done when the plant is in the vegetative stage, but you stand to gain more if you lollipop the plants just before switching to flowering. Some growers do it when the plants are about two to three weeks into their flowering stage. You can also perform this technique when the plant starts producing buds.

Lolllipopping is also best for those that don't have powerful grow lights. For example, if you have nothing other than CFL lights, it's best to use every bit of it on just the top buds because the lights will not penetrate deep into the canopy. However, if you're using powerful lights like LEDs or HPS lights, make sure you don't Lollipop too much! 

Growers often commit the mistake of removing too many buds from the bottom and end up with fewer yields. Sure, the plant does produce more when you remove leaves and buds at the bottom, but don't overdo it as the buds at the base can develop well if they get enough light.

So, how much should you precisely remove? You can remove the growth below the trellis for starters, but leave them alone if they are receiving light. Remember, Lollipopping is a technique used to utilize your light properly, so there's no reason to do if you've nailed it with LST already.

Defoliation

Many people confuse Defoliation with Lollipopping, but they aren't the same. While Lolllipopping means that you remove both buds and leaves at the bottom, defoliating involves removing only the leaves.

Defoliation is a technique where you remove the plant's leaves to force it to grow bushier. Cannabis plants in the wild tend to grow stronger when they are stressed. For example, a deer may find the plant particularly interesting and decide to eat a few leaves. It may even snap off a branch or two, but the plant simply grows back even stronger. You're simply stressing the plant and forcing it to grow bigger and better by defoliating.

Again, defoliating will work if you get the timing right. You can defoliate as much as you want during the vegetative stage, and the plant will quickly grow more leaves, but you can also defoliate in the first few weeks of the flowering stage, so the plant displays explosive growth. It's best to not defoliate beyond the third week — you don't want to push your luck — unless you have a lot of experience with this particular technique.

That said, remember not to use all techniques on the same plant. For example, you can start with Topping and LST the plants in the vegetative stage and defoliate occasionally, but you don't have to Lollipop and FIM the plants.

In addition, remember that horizontal cannabis trellising is nothing but ScrOG, so you're employing one of the best techniques already.

How to Trellis Cannabis?

Trellising cannabis plants, whether indoor or outdoor, is relatively easy. Below, we teach you how to trellis your cannabis plant in indoor and outdoor environments.

Trellising Cannabis Indoors

Trellising is often associated with large outdoor plants with big branches in gardening communities. But in the cannabis community, trellising is used for both outdoor and indoor plants. 

The difference between the outdoor and indoor techniques comes down to style and size. 

Generally, trellising refers to vertical support, but indoor grow tents require horizontal support. Therefore, the trellis tends to be horizontal and supports the branches, and prepares an even canopy to ensure each branch gets enough light and airflow to grow massive buds. 

Regardless of the environment, trellising is recommended only for vigorous growing cannabis strains. Your cannabis plant must have robust growth, dense branches, and respond well to Topping or Super Cropping.

Some of the best strains for trellising include Gelato, Bruce Banner, Amnesia Haze, Purple Punch, OG Kush, and Blueberry. 

Step by step guide to set up an indoor trellis 

We have a complete guide on ScrOG with a detailed explanation. Here’s a quick summary. 

Equipment needed:

• PVC, wood, or bamboo stakes — If choosing PVC, ensure it has a high heat rating
• Trellis netting
• Zip ties or planters tape
• Rope ratchets (optional)

Indoor trellising process:

Gather your equipment

Gather your equipment and get ready to build your trellis!

Create the support structure

Whether you choose PVC or wood or bamboo, place them in the corners.

Drape the net

Once the plant grows a few nodes and enters the vegetative stage, it's time to place the trellis on the canopy. In other words, you'll be draping a let on top of the plant. Use zip ties to anchor the nets to the frame. 

Tuck the plants

Tuck the top of each branch through individual holes in the net until the entire canopy is of the same height. Make sure you allot one bud per hole. 

Drape another net

Once the plant begins to flower, drape another net to support any heavy flowers.  This step is completely optional and you can do it only if you have exceptionally big buds. And once the plant grows, you may have to raise the stakes (literally). To avoid the trouble of lifting the entire stakes structure, you can use rope ratchets to fasten the frame to the ceiling. Then, you can pull the frame up. Or, you can build a taller frame at the very beginning and train the plants according to the structure’s height, as shown in the images. 

Harvest the buds

You may also need to manipulate the plant to prepare it for the trellis frame. For the same, you can use LST, Topping, or Super Cropping to grow an even canopy that’s suitable for the grid. Next, wait for the plants to finish flowering and harvest the buds. 

Trellising Cannabis Outdoors

Outdoor plants tend to grow massive in size, so vertical trellising is recommended to hold the plant in shape. It is similar to growing a grapevine. Here, the frame supports the plant, giving it the appearance of thick foliage.

Many growers wonder if it's even necessary to trellis cannabis outdoors. After all, you're growing the plants in fertile soil, and they don't need any other support, right?

Wrong.

Although the conditions are favorable for cannabis plants growing outdoors, it's always better to control the plants. While you can manipulate many factors and grow the plant according to your needs indoors, much goes beyond your control outdoors.

Cannabis plants flower according to seasons, but you can make the plant think the seasons are changing by manipulating the light it receives. However, you cannot do this with outdoor plants. Therefore, they go through a long growing season that often results in huge plants. Imagine 6-9 months of vegetative growth outdoors compared to mere 2-3 months indoors. For this very reason, outdoor plants require more care compared to plants growing indoors.

To gain some control over your outdoor plants, you can start by growing them in containers, for starters. This way, you can avoid soil contaminants and also prepare a fertile growing media for the plants. This is not to say that natural soil is infertile, but growing in containers will give you better control.

Another way to control how your plants grow is to support them with a trellis. Why? Since outdoor cannabis plants tend to be gigantic, they can simply topple and fall over against strong winds. If you live in a location that is susceptible to heavy storms, you need to be extra careful and offer every kind of support the plant needs. Imagine putting in all that effort to grow a huge plant only for it to fall over. You simply lose huge yields.

Therefore, just like a tomato plant needs support from falling over, cannabis plants need extra support to prevent the buds from toppling. In addition, if you choose to grow in containers, you have to choose the right size to grow plants. If the containers are too small, the plants will have a tough time supporting themselves. The same goes for large containers, so you need to research the strains, genetics, and size to get the best containers.

Step by step guide to set up an outdoor trellis 

Equipment needed:

• PVC, wood, bamboo stakes, or metal t-posts
• Trellis netting
• Zip ties or planters tape

Outdoor trellising process:

Gather your equipment

Firstly, gather all your equipment. Although you can use PVC, wood, or bamboo stakes as mentioned above, you can also use metal t-posts that do a fine job of holding the structure. Since the plant will rely on this structure, use something strong and durable. 

Add a tomato trellis

This is a very crucial step that determines how the plant grows. 

Remember, this structure will hold the plant for almost a year, so it needs to be strong. Some growers will use a tomato cage at the center for internal support, as shown in the image above. You can do the same or skip it if you’re going to drape a net over the structure later. 

Add the poles

Place wood, bamboo, or PVC stakes into the planter bed around the plant. It should represent an imaginary square. Do not skimp on this because the plant will support itself on the structure you build. If you're unsatisfied with the support provided by bamboo stakes or PVC pipes, choose metal t-posts instead. 

Add horizontal support

Next, place a strong galvanized chicken wire in between the poles. You can also use a heavy-duty wire cage. Just make sure you measure everything before cutting so it fits inside the frame. Or, stretch a trellis net around the stakes to surround the plant from all directions, if you're using a net. Use zip ties to tie the net to the poles. If your plant grows too strong, the net may collapse, so use a strong net. 

Position the Branches

Once the plant grows towards the horizontal trellis, you can tuck the tops. Make sure there’s one cola per hole. Again, this will provide extra stability and support to the entire structure. 

Add another layer of support

Wait for the plants to start flowering. You’ll notice that the buds are exceptionally huge if you’ve taken care of them properly. Since they outgrow the trellis pretty quickly, you can now add more support. Some growers install additional support by adding another horizontal trellis or caging above the first one. Additional support will ensure the plant stays upright at all times and reduce the risk of toppling over. 

Wait for harvest

Finally, you’re done with everything and just have to wait for the best part — harvesting your plants. 

Remember, growing sites differ a lot. What works for one may not work for the other — the steps mentioned above may vary for you. However, these steps aim to give you a general idea to trellis your cannabis plant. 

Summary: What is Cannabis Trellising and How Do You Do It

Trellising your cannabis plant, whether indoor or outdoor, is a promising project. It doesn’t take long to set up and won’t cost you much money. However, the efforts you invest will reward you with terrific yields. You may experience 4x yields from the same cannabis plant if you do it the right way!

So, if you want to improve your yields without growing more plants, trellising is the way to go. Just keep these factors in mind:

• Use the right strain that can handle the training. 
• Ensure the PVC that you use has a high heat rating as it tends to leach out toxins under high temperatures. 
• Use netting made from cotton, jute, or hemp; avoid twine as it tends to fray a lot.
• Finally, use suitable training methods to prepare the plant for trellising.

That’s it. Follow these steps and get massive yields!

Last but not least, remember that trellising cannabis plants is a must if you’re growing strains that tend to grow into gigantic plants. Beginners may not understand the importance, but give it a try, and you’ll be amazed by the results. Whether you grow outdoors or indoors, trellising will protect the plants from doubling over and prevent you from losing your precious buds.