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Stop seedlings stretching and falling over

How to Stop your Marijuana Seedlings from Stretching and Falling Over

Marijuana seedlings stretching and falling over can be a common occurrence in the early stages of the cannabis grow cycle. With that being said, it doesn’t need to be so detrimental to your grow. Find out here all about seedlings stretching and how to prevent it.

Your cannabis seeds sprouted, tiny leaves unfurled, and your little plant seems happy and healthy. It’s growing taller every day — a sign that hopefully promises a glorious crop, heavy with sticky colas. 

So far, so good until you notice that dreaded cannabis stretch. If you’re asking yourself,  “why is my weed plant growing tall and skinny?” then you’re not alone.

It’s a common question that plagues the minds of cannabis growers more often than you think.

Leggy, elongated, and weakened stems can lead to a host of problems, affecting your weed plant’s future growth, and ultimately, the quality of your yield.

So, what in the great ganjaverse can you do about your pot plants stretching too much, why is it an issue, and how do you prevent it from happening?

leggy cannabis seedling

Our in-depth guide has all of the answers, from weed seeds and stems to tried and trusted solutions.

Understanding the seedling stage

Before you learn how to prevent cannabis stretch, it’s a good idea to understand the seedling stage.

Marijuana seeds are tiny time-bombs, complete with genetic blueprints and everything they need to spring into life. With only one shot at existence, they’re pre-programmed to survive.

young weed seedling

Quality also matters, though. If you want the best chances of germination and a successful crop, only buy cannabis seeds from a trusted supplier like i49.

During their initial days, marijuana seedlings don’t need any food. They live off their own nutrient reserves, designed to help them establish a foothold in their environment. Let’s take a look at how the seedling stage unfolds:

  • The germination process begins once the cannabis seeds are exposed to moisture, air, temperature, and darkness. First, they undergo a period of dormancy, waiting until the conditions are optimal for survival and development.
  • The shell soon cracks open. The taproot (radicle) emerges, digging deeper into the ground in search of a water source.
  • Next, the shoot (hypocotyl) grows up towards the light. Your cannabis plant will sprout, showing off its first baby leaves (cotyledons) that fan outward from the stem.
  • The first set of serrated fan leaves also form from the top of the weed plant. They act like solar panels, absorbing light to produce food for the crop. The root system also develops, getting ready to usher in the next growth stage.

The seedling phase usually takes 2-3 weeks but can extend up to 6 weeks before the plant moves onto the vegetative stage. During this time, make sure that you know how to keep your marijuana plants short, strong, bushy, and healthy by following the advice below.

Why do seedlings stretch?

Seedlings can stretch for several reasons, some of which are biological while others are environmental.

In response to stress, a weed plant uses its energy reserves to quickly shoot up, resulting in leggy, stringy, or spindly stems. It’s a survival mechanism that triggers when growing conditions become compromised or unsustainable.

cannabis seedling is stretching too much

Cannabis plants originally grown in crowded areas or indoors could pass down such a genetic trait, bearing taller offspring with longer stems. Randomly crossing two strains could also result in a leggy crop.

the seedlings are too tall

Tall marijuana plants naturally occur too. A pure landrace sativa crop is one example —  it’s known for its height in both indoor and outdoor growing environments.

Cannabis seedling stretching

If your pot plants are growing tall and skinny due to biological reasons, there’s not much you can do. When it’s an abnormal occurrence, though, it’s best to understand the causes, as follows:

Lack of nutrients

If your cannabis seedlings are falling over due to elongated stems, it could be because they’re not getting enough nutes.

Nitrogen, phosphorous, and potassium are among the most essential ones absorbed through the roots. Meanwhile, carbon, hydrogen, and oxygen are soaked up through the leaves.

In the first phase of their life cycle, marijuana plants are fragile. They only need moderate doses of nutrients to thrive. Still, if they can’t absorb the required nutes, they’ll go into survival mode, resulting in weakened, spindly stems.

Poor temperature levels

Although cannabis seedlings thrive in warm, humid conditions, too much heat is detrimental. It slows down the growth rate of a weed plant’s leaves, causing thin, tall, and leggy stems.

The higher the temperature, the longer the stems grow. At about 80℉, seedlings start stretching and falling over, resulting in a weakened, comprised cannabis plant. 

Many cultivators also mistake light burn for heat-induced marijuana stretching. If your grow lamps are too close, you’ll have weed plants falling over in protest after becoming spindly and tall.

Incorrect lighting

Lighting is crucial, but too much or not enough of it causes marijuana to stretch. With just a few tiny leaves, cannababy plants only have a limited surface area available for light absorption. They can quickly become stressed when there isn’t sufficient luminosity.

ideal light for weed seedlings

Shade avoidance response phenotype” or SARP describes the act of a plant expanding its stems to reach the light stolen by neighboring flora and fauna. This can happen indoors, too, even if there aren’t any competing light-sappers.

Other environmental factors such as growth cycle and temperature can also trigger SARP tendencies.

If your weed plant is falling over, with feeble, stretchy stems, it could be because:

  • Its photoperiod (light exposure time frame) is too short
  • The light intensity isn’t sufficient
  • There isn’t enough light 

While red light promotes vegetative growth and photosynthesis, overexposure can also make your pot plants grow tall and skinny. Want to learn more about growing light for weed seedlings? Then, you definetely need to read our latest article on how much light a weed plant needs.

Improper spacing between plants

As cannabis seedlings develop, their leaves could end up a little too close to their neighbors. This results in a constant turf war for light and, if you’re not careful, marijuana stretching.

Seedlings are aware of their surroundings and can sense when another plant is mooching off their light. In this scenario, SARP and survival mode kick in, causing cannabis stretch and stringy, wiry, and weak stems.

Improper spacing can also lead to a weak sub-canopy and discolored leaves.

Why is seedling stretching an issue?

Mary Jane plants can develop stretched stems whether they’re growing outside or indoors. It can be easy to miss them, as a spindly, tall marijuana plant can still be quite big.

stretching seedling is an issue

The kicker comes when it’s harvest time, as stretched plants have a significantly lower yield. They end up burning a hole in your pocket with very little return on your investment. It’s also more expensive to nurture them since their long stems demand extra energy.

It makes for a blue harvest, especially when all that effort could’ve gone into cultivating bigger, better buds. With their weak and fragile stems, seedlings stretching and falling over can be disastrous.

stretching marijuana seedling

Fortunately, there are ways to prevent the wretched stretch and even bring cannabis plants back from the brink of bad future yield.

Dealing with seedlings stretching indoors vs. outdoors

Indoors, lighting challenges are usually to blame for low-yielding, stretched plants. Crowding issues, temperature fluctuations, insufficient airflow, and humidity levels are other common bumps in the road that lead to long-stemmed seedlings.

Most of these factors don’t apply to outdoor environments, but the quality and quantity of sunlight are both vital. That’s why your growing cycles should be in sync with your regional climate.

Shorter daylight hours can cause seedling stretching regardless of how much sun your plants get during the day. Outdoor cannabis crops may also need extra nighttime lighting during some seasons – even in tropical climates.

Preventing seedlings from stretching and falling over

Ready to learn how to stop your seedlings from stretching and falling over? Check out these solutions:

Implement good air circulation

Outdoor plants benefit from the open air, which naturally restricts stretching, while indoor plants require a bit more effort.

When you’re learning how to strengthen plant stems, the first step is implementing effective air circulation. It creates leaf and plant movement, which, in turn, stimulates thicker, rather than taller, growth.

If your cannabis plants are in a confined space, you can set up an oscillating fan above them to improve airflow. You can also brush the leaves to mimic the effects.

Improve lighting conditions

The right amount of light is essential for healthy seedlings. The type of bulbs you use also contribute to your plant’s development. Here’s how to keep marijuana plants short and bushy:

  • Red and orange stimulate stem elongation, while blue encourages shorter, stockier growth, so it’s best to get lamps with the latter.
  • Place 200W metal halide lamps above your seedlings at a distance of about 40 inches. Some growers use a 12W CFL bulb approximately 2-3 inches from the top of the weed plant. The temperature should never exceed 77℉.
  • Use infrared lights to restrict vertical growth even more in the flowering stage. Remember to cover the heat reflector with a black cloth for the best results.
  • Ensure your outdoor plants receive enough sunlight and expose them to artificial light in the evenings if need be. Generally, 16 hours of light a day is sufficient for garden and indoor crops.

Space your plants out properly

You can also make marijuana plant stems stronger by spacing your crops out. Find out the average adult size of your seedling, and add a little extra room for good measure. If you’re growing indoors, make sure to include the distance of your lights into your equation.

If you have a large batch of crops, you can use a technique called thinning, where you’ll remove weak cannabis stretch seedlings within the first 1-2 weeks of their lives. You can then dedicate your efforts to the strongest, healthiest plants for an optimal yield.

As a result, your seedlings won’t need to compete with one another for light, so stretching shouldn’t occur. Thinning helps maintain an even canopy in your grow room, ideal for more confined setups.

Reduce temperature (60℉) to stop seedlings stretching and falling over

Aside from tall, thin stems, a seedling’s leaves will also start turning up at the edges when the temperature is too high. In ideal conditions, maintaining a temp of between 68°F to 77°F during the day and about 55°F at night promotes healthy growth.

For seedlings stretching and falling over, a reduced temperature of about 60°F helps thin stems widen while slowing down their growth. Also, make sure that your plants aren’t too close to any lights.

Reduce stress

Since cannabis stretching is a sign of stress, the best way to prevent it is by making sure that your plant isn’t in any distress. The right humidity levels, lighting, nutes, water intake, and temperature will keep your cannababy happy and healthy.

Prevent stretching by taking care of your seedling’s specific needs. Transplant shock and sudden environmental changes also hold your weed plant hostage. If you’re making any alterations, be sure to do them gently and gradually.

How to fix stretched cannabis plants

If your seedlings are stretching and falling over despite your best efforts, you may need to take more extreme measures. Here are two methods:

Re-pot seedlings that are stretching and falling over

You can create a base for your stretchy plants to support and keep them upright, helping the stems grow thicker and stronger. Here’s how:

  1. Make sure the soil is dry so that you can carefully remove your seedlings from their current container.
  2. Clean the roots and put some soil at the bottom of the new container.
  3. Place your seedling into the container and fill it up with soil, making sure to bury the stem.
  4. Add a tiny bit of water, and remember to be extremely gentle.
  5. The buried stems should start growing their own roots.

Use stakes

Here’s how to make plant stems stronger with the staking method:

  1. Measure out a breathable material like fabric or yarn. Alternatively, you could use a stake such as a stick, plastic straw, or even a pencil.
  2. Use the fabric to create a lattice around the weak, spindly stems for additional support. If you’re opting for vertical staking, gently place the stick in a way that keeps the shaky plant upright.
  3. Keep an eye on your marijuana plant and make any necessary adjustments as it grows, but don’t move things around too much, or it’ll cause extra stress for your cannababy.

Strengthen seedlings ready for veg

When seedlings are stretching and falling over, it’s a sign that they’re stressed. Luckily, the above solutions can help you counter and combat weak, thin stems.

Once your weed plants are on the road to recovery, watch them closely and maintain their environment. Get it right, and before you know it, your strengthened cannabis seedlings will be ready for the vegetative stage.

Strong cannabis seedling

Remember, a quality yield starts with top-notch cannabis seeds, like the ones you’ll find at i49. Get everything from crowd favorites Girl Scout Cookies and Green Crack to autoflowering, hybrid, feminized options, and more.

AUTHORED BY: Douglas Kester Mr. Kester came to i49 with a wealth of experience. He’s worked in the cannabis industry for more than ten years. As a growing expert at i49, Douglas finds it hard to choose a favorite strain. Instead, he regards each one as unique and full of potential. Douglas finds it rewarding to experiment with specific cultivars and cross-breed to discover a new one. He strongly believes in sharing the benefits of marijuana with as many people as possible to avoid any misconceptions about the herb. Mr. Kester creatively produces information based on what he’s learned and his experience obtained by implementing what he knows. i49 is proud to have Douglas as part of the team.

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