What Affects Height of Cannabis Plants?


If you’re only growing small amounts of cannabis at home or you haven’t yet started growing you need to prepare to deal with the height of the cannabis, lest you don’t have enough room to accommodate them. The tallest cannabis strains can grow taller than your house, and the smallest strains will be shorter than your knees. There are many factors that influence how tall can a plant grow.

Factors that affect the cannabis plant’s height

cannabis strain-What Affects Height of Cannabis Plants

There are two main types of cannabis, Sativa and Indica. Sativa can grow very tall, up to 20 feet tall, and likewise, their harvest time is slower. Indica is usually short and wide, with a bush-like appearance. There are also a lot of hybrids available now and their height is hard to pin down because there are different genes at work.

If you purchased hybrid seeds please read the specifics for that strain carefully—usually, your seller will include information about the strain in the package. Finally, Autoflowering varieties are photoperiod-independent flowering cannabis strains, and they typically grow between 1.5-3.5 feet, making them ideal for small spaces.

While Sativa can grow very tall, that doesn’t mean you have to let them grow to its maximum height: you can control the height of cannabis grown indoors. In general, we do not recommend growing marijuana that is too tall. Tall cannabis plants prevent light from penetrating the canopy to the branches at the bottom of the grow tent, which is not conducive to them producing enough buds.

Besides, tall cannabis is not necessarily more productive than low cannabis, which makes it even less necessary to grow cannabis that is too tall—plus they also take up too much space.

Training Techniques

To increase yields, almost all farmers train their plants. This training put a certain amount of stress on the plant and even damages the plant epidermis, awakening the potential of the plant to produce more buds. During this process, since the plant is spending all its energy on repairing itself and producing more buds, there is naturally not enough nutrition to grow taller. Common training techniques are low-stress training (LST), the screen of green (SCROG), and topping. For specific practices of these techniques, see this article.

Growing Stages

There are three stages of cannabis cultivation: seedling stage, vegetative stage, and flowering stage. Cannabis plants in the seedling stage grow their first set of true leaves; the vegetative stage is when the cannabis plant grows branches and leaves; and the flowering is the stage when the cannabis blooms. If you choose to grow cannabis strains that spend more time in the vegetative stage, they will usually grow taller than cannabis strains that spend less time in the vegetative stage.

Spend extra attention to plants during the vegetative stage, if you have an exact height you want to grow, you’d better transition your cannabis to flowering when your plant is half the height that you want it to be because, during the flowering stage, your cannabis plant will double in size.

What Affects Height of Cannabis Plants

We know that lights are pretty much the most important thing in growing cannabis indoors. Without lights, your cannabis plants simply cannot grow. If you choose the wrong grow lights for your tent, especially if the lights you choose are not powerful enough, your plants will certainly not grow to the heights they would otherwise have, and of course, yields will be minimal.

So if you don’t have much experience be sure to pay attention to what advice other farmers who are growing the same plants as you have said—if your plants are noticeably shorter than theirs you may not be providing enough light and you need to re-select or add grow lights for your space.

Is there an optimal height for cannabis?

There is no optimal height for cannabis. To a large extent, your plant height depends on your setup. But now that we have learned some basic concepts you can explore the height of the cannabis plant that is most suitable for you according to your needs and existing conditions.


In addition to height, the overall size of the plant also has a large impact on yield. You need a wide, flat canopy of plants that allows each branch to get as much light as possible to maximize yield.

If you have any questions, please don’t hesitate to reach out to us!

And be sure to check out our other blog posts for useful tips on becoming a great grower!

Indoor growing just got an upgrade. The new smart grow system allows you to fully automate and control your indoor garden with the push of a button, no matter where you are. This innovative system monitors and adjusts settings like lighting, temperature, humidity and more to create the perfect environment for your plants to thrive. It takes the guesswork out of growing and makes it easy for anyone to cultivate plants indoors. If you’re ready to step up your indoor gardening game with some high-tech help, this smart grow system is the modern solution you need. Transform your indoor garden and join the future of effortless gardening today!

Take your gardening skills to the next level by subscribing to the VIVOSUN newsletter. You’ll get exclusive growing tips, inspirational stories from fellow gardeners, and special discount offers delivered right to your inbox.

We love the new VIVOSUN Smart Grow System and we are certain that you too will love it once you try it.

And join our Facebook farmer’s community for even more exclusive contests and prizes!

Download VIVOSUN App to get 18% off and explore more information!