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Why Is My Weed Plant Growing Tall and Skinny?

Why Is My Weed Plant Growing Tall and Skinny? The Seed Fair

Most growers are looking for a large width in their cannabis plants. Tall and slender plants can be problematic. There are several potential explanations for your plants’ extraordinary tallness, and most have a way to fix the issue.

The source of your plant’s growth spurt might be tough to detect, ranging from having improper light exposure to leaving the plants in the vegetation phase longer than normal. Understanding the specific strain genetics is vital to ensure your marijuana plants aren’t growing too tall. You might be also interested in how tall a weed plant grows – check out our publication on this topic.

Why are my pot plants growing so tall and skinny?


The DNA of weed plants is responsible for controlling their development features. Agricultural methods do, without a doubt, have a significant bearing on the development of plants. However, certain varieties have reached heights well beyond average, and not all have thin stems. Before you start growing, research the specific strain you want to grow to have enough room for it.

Long vegetative stage

Once the seed has germinated, the cannabis plant will enter a vegetative state, developing the majority of its leaves. Your time spent in the vegetative state could range from a couple of weeks to several months, depending on your genetic makeup. If you leave your weed plant for a lengthy period of time, it may experience excessive growth in the vertical direction.

Distant or weak light source or uneven light distribution

Plants can grow long tendrils to reach light sources quite far away. Because of the greater space between them, LED lights are more sensitive to this issue than fluorescent or HID lights. It’s possible that the light distance will need to be fine-tuned to achieve the desired result. Take into consideration how bright your lighting is, as well as the available space.

You may experience unnatural plant stretches and development if exposed to not enough light, such as distant lights. It’s possible that using light bulbs that don’t produce enough watts or lumens for the proper growth stage you’re working with will cause your plants to elongate and grow taller to compensate for the lack of light. Fluorescent lights, which are the least powerful, are the ones that exhibit this problem the most frequently.

You could still wind up with tall and thin plants even with proper light output. This is typically the result of plants having too much light coming in from the top. Growers remedy this issue by either deploying supplemental lighting on the sides of their grow space or installing reflective materials on the walls of their grow rooms.

Plants are too close to each other

A shade avoidance response phenotype occurs in plants when bordering vegetation is too near. This is a common issue with weed plants with many side branches. If you position them too far apart when you first plant them, the plants grow closer together and compete for the room. A competing plant develops a taller stature to cast less shadow.

A good rule of thumb is to leave at least 6 inches (about 15 centimeters) of space between the branches of each marijuana plant. If you are interested in learning how to cultivate a compact and bushy weed plant, a distance of half a foot is an ideal choice.

Why is my plant growing tall and skinny outdoors?

If given the opportunity, cannabis plants grown outdoors will continue to grow tall if the right conditions exist. Since there is little to control with outdoor weather, growers run the risk of their whole plant growing tall and skinny.

With cannabis plants being attracted to the sunlight above them, this causes unnecessary stretching to happen. Growers will need to take more time to trim their weed plants to stop them from becoming tall and skinny.

Why Is My Plant Growing Tall and Skinny Outdoors? | The Seed Fair

What happens with tall and skinny plants?

If you are starting out in cannabis growing, it might be disheartening that your plants do not look as bushy and robust as those pictured in online photos. The reason why plants can extend their height while maintaining their width is not easily explicable.

Nutritional deficiencies

There is a possibility that the plant will not make effective use of its nutrients if it is tall and slim. Most of the cannabis plant’s energy will be put into keeping itself upright. Consequently, the supplemental nutrients will be put toward the development of trichomes and buds. It is not as simple as providing your plant with additional nutrients because there is a danger of overfeeding, which can result in a nutrient burn, potassium deficiency, or calcium deficiency.

Weak stem

Your plant will not be able to sustain itself until it has developed a primary stalk that is tough and durable. During the seedling and vegetative phases of their growth, the plants may give the appearance of drooping and twisted due to their top-heavy development. During the blooming stage, the problem becomes increasingly severe. A plant’s bud development might become excessively weighted, causing it to droop, topple over, and possibly sustain damage.

Space, climate, and light problems

A tall and slender plant can quickly force the majority of growers to run out of space. As a consequence of this, the plants may end up growing too close to the light bulb, which would necessitate extensive trimming but will result in a decrease in yields. This can also lead to light burn.

Aside from the limitations of space, your tall and thin plant has the potential to reach up to or come quite close to your lights. Your plants could catch fire if kept too close to lights, particularly LED or HID bulbs. If the issue is not fixed, you risk destroying your crop because you cannot remove the lights and must keep them in place instead.

Tall and slender plants have the capacity to collect more warmth from the light source and emit it into the environment, resulting in increasing temperatures. Additionally, tall plants have the potential to hinder adequate airflow and ventilation, which raises the risk of mold growth as well as disease.

How to stop a plant from growing tall and skinny

Select the right strains

It all begins with the genetic makeup you select. Sativa strains, on average, grow tall. The Indica strains are considered to be small weed plants. Furthermore, autoflowering plants do not grow very tall.

Low-stress training (LST)

Using this method, you will gently bend the branches down while tying them together. There is the risk that the branches will be broken if the plant is bent too much. If you are successful, you will prevent the plant from growing taller, and you will produce a wider canopy, resulting in improved light distribution.

Top & prune cannabis plant

If you feel your plant has become too tall for your preferences, it is probably time to start trimming away some excess foliage. It is recommended that you complete this step before the flowers begin to form on your plants. This gives them time to recuperate before the flowering stage and ensures sufficient space for development during the subsequent stage. In certain circumstances, the height of a plant may double while it is in the flowering stage.

The screen of green (Scrog)

Your plants can be kept at a more manageable height with the help of nets and screens, which also help spread the light more evenly. You can broaden your canopy by using a screen, allowing more light to reach each branch. It encourages horizontal growth, enabling the appropriate amount of light to penetrate all of your plants.

Shorten the vegetative stages

It is not recommended to keep your plants in the vegetative stage for a longer period of time than is strictly required. Find out how long your strain should be in the vegetative stage and, if necessary, keep it shorter than the recommended period if it gets too tall and thin.

Set up lights right

Before you start planting, you need to consider the distance that each of your grow lights needs to be from the cannabis plant. With this knowledge, you can make an informed decision about which genetics to use to reduce the likelihood of your lights damaging your plant.

Optimize growing space

If it is at all possible, you should pick a grow room that is big enough to reduce or get rid of the issue of having plants that are too tall and thin. The ability to properly position your plants and lighting is simplified by higher ceilings. This can be of assistance in preventing the chance of the plants becoming overstretched.

Use reflective materials

Reflective materials in your grow room can considerably increase how evenly light is distributed. The light does not come from a single source on top of the plant; rather, it bounces off the sides and strikes the plant from all angles. This results in more consistent development that is not restricted to vertical growth. If you want a plant with more bushiness, add some extra lighting along the sides of the pot.

Become a professional grower

Become a professional grower with the great selection of seeds from The Seed Fair. Their knowledgeable staff is there to help you find the seed solution you are looking for and can help you if you start to see your marijuana plants become tall and skinny.

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