Anyone interested in cultivating cannabis — professional growers and amateurs alike — should have at least one go-to plant training technique in their arsenal. Training techniques allow cannabis growers to manipulate weed plants to grow into certain shapes and patterns in order to produce more buds than they would if left to themselves.
This guide will walk you through the basics of training weed plants, including how to top cannabis plants and much more, so that you can get bigger yields.
Why cannabis topping is important
If left to grow naturally without human intervention, cannabis plants tend to focus their energy on the production of one main cola, with a series of small bud sites below. This natural growth pattern, which takes on a Christmas tree shape, is not ideal for optimal bud yield.
If you let your cannabis plant grow this way, the lower branches and the budding sites located on those branches typically don't receive sufficient light exposure so they tend to naturally grow much smaller nugs relative to the main cola. Unless you plan on growing a cannabis plant with a Christmas tree shape, and lower yield, your plant will need some training.
There are several training techniques growers can deploy to get an optimal yield out of their plants with limited space and lighting conditions. You can train a plant's height, width, number of cola growth tips, and the evenness of the canopy to help increase nutrient uptake, deter bacterial spread, and improve overall yield.
Most growers have a variety of reasons to train their plants. Encouraging a dense, even canopy; facilitating large, compact cola production; ensuring proper airflow to reduce bacterial development; and reducing flowering time for an early harvest are all common reasons for training cannabis plants.
If you have limited height in your home or backyard, you may want to top cannabis plants to limit vertical growth during vegetation. If you have low plant limits in your state and want to get the most out of each plant, you may want to train your plants to encourage lateral growth. You may only have one plant left, and need to train it to be a mother plant so you can maintain the genetics. Whatever the reason, training your cannabis plants can yield hefty, healthy results.
When to train your cannabis plants
You may wonder if it's best to train during the rooting, vegetative, or flowering phase. The answer depends on what your end goal is. If it's to keep mother plants healthy and in a position where they can produce clones, the plants will need constant training. If you want to ensure plants stay short throughout the flowering phase, train during the vegetative phase. If you're trying to redirect a cannabis plant's energy from many growth sites to a few, the first couple weeks of flowering are the time to train.
The most effective training techniques for marijuana plants
Unless you plan on growing a huge bushy plant that looks like a Christmas tree, your crop will need some amount of training. Decide what your goals are — whether it's shortening the vegetative period, producing larger colas, getting an even canopy, or something else — and apply the appropriate techniques to achieve those goals. You'll likely find you need to perform more than one training method for optimal results.
Controlling the light
For indoor plants, you need to manage each growth phase by controlling the amount of light available. If you are limited to only one outdoor season with restricted plant counts and want to ensure a bountiful harvest, train your cannabis plants indoors and place them outside during the summer solstice.
Unless your cannabis plants are from autoflowering cannabis seeds, they will stay in the vegetative phase, not producing colas, as long as they get more than 16 hours of light every 24-hour cycle. Keeping your plant in the vegetative stage will allow you to start rooting a clone indoors and train it to be whatever height you'd like prior to placing it outdoors and letting the natural sun cycle take over.
For example, if you start growing a plant indoors during April or May in the Northern Hemisphere, your plant could be as tall as 10 feet (3 meters) by the time you place it outdoors to start flowering. By the time you harvest the plant, it could be well over 15 feet tall ( 4.6 meters) and produce many more flowers than a plant introduced to the sun at 3 feet (0.91 meters).
The light deprivation (aka light dep) technique can also be used to force plants to flower in a greenhouse setting by reducing the amount of naturally available light. Using light dep techniques on varieties with short flower cycles allows cultivators to get the most out of the outdoor sunlight without overextending the vegetative cycle. You can also extend natural flowering cycles using supplemental lighting in areas with long winters to ensure your plants have enough light to flower and aren't exposed to extremely cold temperatures.
Deleafing is removing the large fan leaves or small flowering sites from a cannabis plant. It's the most basic form of training, usually performed at various points of the vegetative and flowering stages.
Removing large fan leaves during the second half of the vegetative phase diverts plant energy to other growth sites and allows for more airflow throughout the plant, drastically reducing the likelihood of bacterial spread. During the flowering phase, some leaves may be blocking valuable light to crucial growth points. It's also possible for small budding sites at the bottom of the canopy to divert energy that should be used elsewhere in the plant. At these points, the leaves or small growth sites should be removed.
Topping cannabis plants is a technique to encourage new growth and the production of more branches, effectively doubling the yield of your plants. It's accomplished by clipping the growth tip of the plant's main stem, which is found at the very top of the plant, causing multiple colas to form instead of just one. When topping a plant, make sure to cut it at a 45-degree angle.
Topping cannabis plants this way slows down the vertical growth of the plant, which allows lower bud sites to catch up to the upper growth on the main stem. Cultivators can employ topping repeatedly to get even larger yields, topping dominant growth tips multiple times to turn one growth tip into two growth tips, two into four, and so on.
Similar to topping cannabis, the FIM method (or fimming) involves cutting the main tip. But fimming takes most of a budding tip, rather than cutting it completely at a 45-degree angle. The intention is to spur new growth, producing many colas in the place of one main cola. Developed from improperly topping the plant (hence the name FIM, short for “F**k, I missed”), fimming could lead to an uneven canopy as it's difficult to control the extent of developing growth sites.
Using sea of green (SOG)
The sea of green (SOG) method is typically used to promote the shortest possible vegetative phase, which leads to the production of a single, dense cola. It involves growing many small cannabis plants instead of a few large ones. While the yield per plant will be smaller with just one cola, overall yield will be larger as you pack more plants into your grow space. Clones of the same age are usually recommended for SOG grows.
Using screen of green (ScrOG)
If local laws limit the amount of cannabis you can cultivate, the screen of green (ScrOG) method will allow you to create more growth sites per plant, which translates into more flowers. The ScrOG method forces cannabis plants to grow through a suspended horizontal screen, allowing colas to form in otherwise dormant areas of the plant as it spreads laterally across the screen. The theory behind the ScrOG method is to manipulate the plant's branches to grow horizontally, rather than vertically, so that more flower nodes are exposed to the light source.
Low-stress training (LST)
Instead of letting your plant go crazy growing vertically with no limits, low-stress training (LST) involves bending and tying down plant stems for maximum yield and light exposure for a chosen area on the cannabis plant. The term low stress refers to altering stem growth without pursuing a more high-stress training technique such as extreme bending, breaking, or cutting the main stem or side branches. LST is usually performed in conjunction with the ScrOG method and should typically begin during the plant's vegetative stage before stems are hard and unpliable.
Rather than emphasizing sustained levels of low stress, super cropping involves strategically executed forms of high stress to boost the plant's development of cannabinoids and terpenes. Super cropping consists of pinching areas of the stems and tying them down. The plant then sends more energy to that area for healing, thereby increasing nearby bud production. If you try super cropping and end up applying too much stress, apply duct tape to the damaged area to help the plant heal.
Removing growth from the lower portion of the plant, resulting in a lollipop- shaped plant, diverts more energy to the higher, cola-producing branches. Since the lower branches don't receive much light anyway, this method removes them, forcing the plant to focus on cola growth. For SCROG and other indoor cannabis grows that allow minimal light to the lower branches, lollipopping is especially effective in encouraging an optimal yield.
Frequently asked questions
Does topping increase yield?
If you top your cannabis plant correctly, it should increase yield. Basically, when you cut off the top of the plant, it encourages lateral branches to grow and each of these additional new branches will eventually grow their own buds. Topping lets you get many more flowers out of a single plant.
What happens after topping a plant?
After you top a marijuana plant you will eventually see new shoots of growth begin to form at the point where you cut off the growth tip. These lower lateral branches are each capable of producing a cola.
How do you LST after topping?
After you top the plant, wait until the new lateral branches are large and long enough to tie down to a stake. Then, simply perform LST the same way you would normally, by gently bending, tying down, and staking each branch to train it to grow the way you want it to.
How do you top clones?
There is no difference between topping a marijuana plant grown from seed and a clone. Once your clones are large enough, use clean pruning scissors to cut off the top of the plant. Make sure to cut at a 45-degree angle. Once the main growth tip is gone, the plant will respond by sending out new lateral branches, which should then grow into cola-bearing branches.
Can you combine training techniques?
Yes, you can combine multiple training techniques. Anytime you're growing your own marijuana, it's usually a good idea to come up with a combination of techniques that will help you maximize growth and yield. Check the specifics above to find which techniques will deliver the results you seek.