During the flowering phase, growth can be controlled by reducing the photoperiod – but only if your plants have been flowering for at least six weeks. Reducing leaf production and stem stretching can be achieved by reducing the “lights-on” period from 12 hours to 11 or 10 hours.
If you are well aware that the strain you are growing is going to be tall, then height control starts in the early vegetative phase. Alternatively, the size of your grow space may require height control no matter the strain. Topping or fimming when plants are young encourages a shorter, but bushier plant. Grow room space still needs to be considered, however, as you are exchanging height for floor area.
Letting your plants grow untouched during the vegetative phase, then topping just prior to flowering also controls height. When your plants are about to enter the flowering stage, top all branches. This has the effect of reining in the flower stretch. The plants are urged to produce new flower growth instead of focussing energy on stretching out.
Light intensity can be adjusted as a method for controlling growth speed and height. Some grow lights have adjustable outputs. If your plants are getting unruly, reduce the intensity. If you are using more than one lamp, simply turn some off.
What’s great about these techniques is an even canopy instead of one main cola. The extreme of this style is ScrOGging, in which the whole plant is encouraged to grow horizontally. A screen of netting is used to hold down all new growth until the plants form a mat. Appropriately called “screen of green,” one or two plants may fill an entire grow space.
Air circulation is a priority when plants become bushier in tight quarters. Controlling the height of your crop, only to suffer from mould or fungus due to lack of circulation is definitely a no-no. Lollipopping your plants will guarantee good air circulation below the canopy, preventing pathogens from taking hold. This also has the added bonus of chunkier and weightier colas come harvest, with less unwanted popcorn buds.
Cannabis plants transpire a substantial amount of water. Marijuana prefers a relative humidity (RH) of 50-65%. When they get too big, humidity can become a problem as the plants constantly release water vapor into the air. Water then gathers on leaves and other surfaces in the grow room, potentially causing mould and other issues. If humidity is becoming a problem, the use of a dehumidifier or increasing exhaust fan power can help. Defoliating can also increase airflow to control humidity. Remove lower and mid-level fan leaves only. This has the added benefit of increasing light penetration to the lower flowering branches.
LST or low stress training is the art of gently tying the branches of your plants to grow more horizontally. Either the main stem is tied down, encouraging the side branches to be dominant, after which the side branches are also tied down; or the plants are topped a number of times and the new growth is tied down in the mainlining style. LST and mainlining have the benefit of exposing more of the plant to light, therefore encouraging weightier flowers all over.
If your plants are getting too tall or too hot and you have the room, simply raise the grow lights as high as possible. Remember, lights that are too far from the tops of your plants can also cause stretching, so make sure to achieve the ideal light positioning.
Cannabis is a hardy plant that can grow too tall for your grow space if you just let it go. Sometimes you need to take charge to keep things under control.
This tall and branchy strain has evolved purely to thrive within outdoor settings and features a high growing difficulty. Indoor and outdoor plants feature medium yields and tall outdoor heights. Malawi Gold features a lengthy flowering time of 14 to 16 weeks, so some serious patience is required.
If you have the space and you’re growing anyway, why don’t grow big, bigger, biggest? Here is our top 10 tallest cannabis strains available.
The flowers of Jack La Mota feature a THC content of between 15–20% and a high CBD content. This cannabinoid profile makes Jack La Mota a highly medicinal strain capable of easing symptoms of chronic pain, stress, anxiety, sleeping issues, and more. The terpene profile within the buds produces fantastic tastes and aromas of citrus, pine, skunk, and fruit.
Indoor strains are capable of providing up to 650g/m² and grow to tall heights. However, their outdoor counterparts truly represent what this strain is capable of by pumping out massive yields of 1500g/plant and achieving towering heights up to 3.5m. Moby Dick features a flowering time of around 10 weeks.
Dutch Dragon can produce varying levels of THC between 17–21%, meaning highs can either be slightly mellow or quite intense. Regardless of potency, the high always induces pleasurable feelings of alertness, euphoria, and happiness. The uplifting and cerebral effects really get the cogs of the mind turning, making this smoke a great choice when having deep conversations with friends. Dutch Dragon is also a treat for the taste buds, offering mouthwatering flavors of sweet, sour, and citrus.
This unique specimen was birthed from a breeding project involving legendary strains White Widow and Haze. The high generated by Moby Dick is especially popular among smokers who prefer more intense and powerful experiences. The outcome is primarily a head high that brings about energetic, uplifting, and psychedelic sensations. The high is long-lasting, so strap in for the ride. The flowers offer tastes and smells of spice and lemon, which add to the intense energy of the high.
This is a 100% sativa specimen that is also a landrace strain, meaning she is purely the product of her native environment. Malawi Gold has developed over centuries in the northern Malawi region of Southeast Africa, where she adapted to the stressors of her habitat. The lack of intensive selective breeding has left Malawi Gold with a medium THC content, resulting in a pleasant high that is clear, crisp, and subtle. It’s a superb smoke for users who prefer lighter highs that don’t overwhelm. Each toke is accompanied by spicy and fresh tastes.
Planting this beast within a garden bed or large pot will unleash the full potential of the magnificent specimen, allowing it to explode to heights of 4m with staggering yields of approximately 2800g/plant! She has a flowering time of 9–10 weeks.
Monster received its gigantic genes through a breeding project involving parent strains Mexican, Mr. Nice G13 x Hash Plant, and Colombian. This genetic medley produced a sativa-dominant strain that features 80% sativa genetics and just 20% indica. These genetics are what makes Monster so imposing in stature.
If you have the space and you're growing anyway, why don't grow big, bigger, biggest? Check out our Top 10 with strains that grow to incredible heights.