Why My Cannabis Seedlings Are Growing Slowly?

Introduction

Why my cannabis seedlings are growing slowly? It is the most common question we get from weed growers. Well, there is no need to panic if you are providing your plant with optimal nutrients, light, and a stress-free environment, then it should bloom. Especially, auto-flowering varieties grow fast with optimum conditions. But if you are experiencing stunned cannabis growth, then you are doing something wrong. 

The slow growth of cannabis seedlings can be attributed to various factors such as inadequate light, improper watering, or nutrient deficiencies. Addressing these issues promptly and providing optimal growing conditions can help stimulate healthier and more vigorous growth in seedlings. Today, we will discuss why your cannabis seedlings are taking a long time to germinate and what you can do about it.

Reasons for the Slow Growth of Cannabis Seedlings

Slow growth or stunted growth in cannabis is due to many reasons, but if you buy quality seeds from a reputed supplier, this issue is minimal. Here are the reasons why you may experience these issues-

1. Low-quality Cannabis Seeds

Yes! You heard it right. If cannabis seeds are of low quality, you may not achieve the desired results. Generally, poor seeds aren’t bred having strong genetics or are from immature seeds. Even poor storage damages seeds’ potency and viability. 

It is why every experienced grower picks cannabis strains with high THC potential, and for that, you can check suppliers’ websites. You can even check reviews of the websites online. Some suppliers guarantee germination like FarmKing Seeds Canada does. You can buy autoflowering and fast-version seeds if you are a beginner.

If you are growing it for the first time, there are two reliable methods- one sow it directly in nutrient-rich soil or between two damp cotton balls. If you want a successful germination rate, try the damp cotton pads method.

Also Read: What Cannabis Seeds Look Like?

2. Under-watering or Over-watering

It is where new growers flow in emotion and provide more water than required thinking, if we water more, plants will sprout fast. It is not how it works- do you eat more food than required, no right. Similarly, too much water suffocates cannabis roots by depriving them of oxygen, resulting in root rot and stunted growth. Symptoms include drooping leaves, yellowing leaves, and soggy soil that stays wet for days, and underwatering causes dry and the pot feels lightweight when lifted.

So, for that, you need to make a water schedule. Stick your finger in the soil, feels damp, so don’t water it. Also, soak the soil until runoff appears from the drainage holes, and always Select pots with drainage holes to prevent water from pooling around the roots. 

3. Small pot size or too big pot size

Another issue common while planting cannabis is buying a small pot as it’s just a tiny seed. But it requires space, small pots stun growth as they do not provide space for root mass and become crowded and restricted causing deficiencies. Even too big a pot size is not good as you may overwater plants. It also applies when there are no drainage holes, clogging leads to overwatering issues. 

For this, always pick a medium-sized container with nutrient-rich coco feed and proper drainage holes to prevent root bound.

Recommended Pot Size for Cannabis

Desired Final Plant Height	Vegetative Time	Recommended Pot Size
Up to 2 feet	Short (2-4 weeks)	1-2 gallons
2-3 feet	Medium (4-6 weeks)	3-5 gallons
3-5 feet	Standard (6-8 weeks)	5-7 gallons
4-6 feet	Long (8+ weeks)	7-10 gallons
Over 6 feet	Extra Long (10+ weeks)	10+ gallons

Related: Choosing the Right Container for Growing Cannabis: Maximizing Quality and Yield

4. Damping Off

Are your plants suffering from thin, discolored roots or mold growth? It may be because of fungal disease. Damping-off is an illness that attacks seedlings, causing them to rot and die by several soilborne fungi, like Pythium, Rhizoctonia, and Fusarium. These fungi thrive in warm, moist conditions and quickly destroy entire flats of seedlings.  

You can prevent damping issues by sowing thinly sterile seeds for air circulation, correct watering, and using fungicide before planting. If by any chance you see problematic signs, remove the infected seed and dispose of it. Plant new seed and take care of it.

5. Light Issues

Cannabis is like other plants. They require proper light for photosynthesis. But over-lighting and underlighting both damage plants.

• Light Stress: Light Stress is a condition when there is more light than required. It may be due to the light source being too close to the plants, Inadequate light fixture for the plant stage, or using the wrong type of light. It causes yellowing of leaves, upward curling, dry, crispy leaves with stunned growth. 

The solution is simple- keep the plant far from the light source, invest in a light meter to check intensity, research which strain requires how much light, and use cannabis cultivation-friendly lights like LED or CMH.

• Light Deprivation: Not enough light is one main issue, as it restricts plants from photosynthesizing. When you notice plants stretch stems towards light or thin weak stems, smaller leaves, and reduced bud production, it is time to increase the light in the plant stage and canopy size. If growing photoperiod plants eliminate light exposure during the dark cycle of the flowering stage. Check for light leaks around tents, doors, or timers.

• Light Cycle Fluctuation: Inconsistent light cycles, especially during the flowering stage in photoperiod plants cause stress as they are sensitive to light leaks. Ensure your tent has no holes for leaks as they may cause hormonal imbalance in plants, causing an extended growth cycle. To combat this, use timers for maintaining proper light cycles and pick auto-flowering strains to combat this issue.

6. Accidental Damage Stresses Cannabis

Accidental damage may seem strange to some people, but cannabis plants are indeed stressed by it because if any item breaks due to any reason, the growth slows down since the plant’s main focus is to repair the item, and nutrient supply is hindered. If a stem breaks accidentally, there is nothing much you can do unless you can use duct tape to secure the stem at the place so that the food supply is maintained.

7. Environment

Most cannabis strains enjoy warm and humid climates. They flourish when they get the optimum nutrients, light, water, and the right kind of surroundings. You can use a hygrometer to adjust the warmth of the grow room between 15 Degrees to 30 Degrees and humidity between 25% – 35%. Maintain a humidity level of 60% during seedling, 50% during vegetative, and 40% during flowering.

8. Nutrient Deficiencies

Are you providing enough nutrients to your cannabis seeds? It is one of the best skills that a grower may adopt from seedling to harvest that requires the right amount of nutrients feeding, no over or underfeeding. Macro-nutrients and micro-nutrient absorption are directly related to pH level. So, adjust the pH level if you are feeding your plants right, but your plants are not blooming. Always feed plants with room-temperature tap water. Cold water shocks roots and slows down growth.

Related- Nitrogen: The Silent Hero For Healthy Cannabis Plants

9. Damaged roots

In hydroponics and aeroponics, roots are visible, but not in other mediums. So, keeping a healthy environment involves good air circulation with optimum water supply. Incorrect pot up and inadequate growing medium can lead to root damage. 

10. Improper pH Levels

pH levels hinder growth as cannabis plants do not absorb nutrients efficiently from the soil, especially for hydroponic growers. Maintain a pH of around 5.8 in hydroponics, 7.0 in soil, and 6.0 in coco coir, otherwise, the plant may cause nutrient lockout if the pH is too acidic or alkaline. 

11. Pests and Diseases Stress

Pests and pathogens can wither any plant, and some environmental conditions welcome bacteria, fungi, and viral diseases that can kill your cannabis plantations. Pests like spider mites, white gnats, etc., are common cannabis pests, and if you are dealing with it, read pests and viruses infecting cannabis garden.

Also, Refer to Identifying and Treating Common Cannabis Pests and Diseases

12. Cannabis Training Techniques Stress

There are two types of cannabis stress training- High-Stress Training HST and Low-Stress Training LST.

• Low-Stress Training (LST): LST involves gently bending and manipulating stems to achieve a desired shape are considered a low-stress technique because the manipulation is gradual and minimal. However, some stress can occur during the initial bending, especially on young plants.

• High-Stress Training (HST): This method involves more aggressive techniques like topping (cutting off the main stem), super cropping (intentional crushing of stems), and firming (partially pinching off the growing tip). HST can cause significant stress to the plant as it recovers from the intentional damage.

To minimize stress from both these techniques, train cannabis plants during the vegetative stage. Also, avoid training during flowering as the plant focuses its energy on bud production. 

13. Age Stress

Cannabis seedlings and young plants are generally more vulnerable to stress. Their root systems are still developing and haven’t yet established a strong tolerance for external pressures. Accidental damage, transplanting shock, or environmental fluctuations can significantly impact their growth. 

While mature cannabis plants, particularly those in the vegetative stage, are generally more resilient to stress. Their strong root systems and size allow them to handle environmental changes and recover from minor stressors. However, mature plants can experience stress from factors, like nutrient deficiencies, light issues, or pest infestations.

To combat age stress in cannabis plants, buy seed strains with high tolerance to stress. Some strains are known for their hardiness, while others are more sensitive. 

How to speed up the Germination procedure?

The initial germination days are crucial, you cannot do anything instead of waiting and letting nature do its job. But there are a few ways by which you can get successful cannabis germination rates like:

• Optimizing seed quality: Always use fresh seeds from reputable sources. Older seeds may have a lower germination rate and take longer to sprout, so avoid them. Also, store them in a cool, dark place with low humidity before planting. It helps preserve their viability.

• Creating Ideal Environment: Aim for a consistent temperature around 70-80 F and maintain moisture to initiate germination, but avoid soaking them or it will become soggy.

• Apply Germination Techniques: Apply the paper towel method, Rockwool method, or warm water soak method, whichever suits you the best. 

In the paper towel method, place the seeds between two damp paper towels in a sealed container and store them in a warm, dark location. Check on the seeds daily and mist the paper towels with water if they start to dry out. Roots should emerge within a few days, and you can then transplant the sprouted seeds to their growing medium. 

In warm water soaking, Some growers swear by soaking the seeds in warm water (around 80-86 degrees Fahrenheit) for 24 hours before placing them in their growing medium. It can help soften the seed coat and encourage faster germination.

Related: Germination Guide

What changes can be made to help Cannabis grow faster?

While there is no magic for fast cannabis growth, several adjustments can significantly improve its speed without sacrificing quality.

First, optimize the environment. Dial in lighting with the right intensity and spectrum for your strain during the vegetative stage. Ensure consistent temperatures around 70-80°F and proper humidity levels (40-60%) for healthy growth. Consider using ventilation and dehumidifiers if needed.

Next, focus on nutrient management. Use a cannabis-specific nutrient regimen that caters to the vegetative stage and adjust the feeding based on your plant’s needs. Avoid over or underfeeding, and consider a well-aerated, well-draining soil mix with a slightly acidic pH.

Training techniques can also play a role. Gently bending young stems (LST) during the vegetative stage can create a bushier plant with more bud sites. Techniques like topping or apical dominance pruning can also promote lateral branching and potentially increase yield, but proper timing and execution are crucial.

Finally, consider your strain selection. Indica-dominant strains with shorter flowering times generally mature faster than average strains. Also, ruderalis strains have a higher tolerance than other strains.

Remember, prioritize healthy plant development over speed. Pushing plants too hard can compromise quality and potency. Focus on creating an optimal environment, providing the correct supplements, and implementing these techniques effectively for happy and productive cannabis growth.

How big should Cannabis Plants be after 2 weeks?

Cannabis plants after 2 weeks are typically still in the seedling stage and won’t be very big. Expect them to be somewhere between 2-4 inches tall. This can vary depending on factors like strain genetics, germination speed, and growing conditions. 

During this stage, plants will primarily focus on developing their root system and establishing the first few sets of true leaves, not the initial single round leaves, called cotyledons. They will typically have 2-4 sets of true leaves with serrated edges by the end of week 2.

When to transplant your Cannabis Seedlings?

Here are the factors that indicate the time to transplant cannabis seedlings:

• Extreme Temperature: If you’re experiencing extreme temperatures (too hot or cold), it’s best to wait for a more stable climate before transplanting. Transplanting during temperature stress can further shock the seedlings and hinder their ability to recover. Aim for a consistent temperature around 70-80°F (21-27°C) for optimal growth.

• Poor Roots: If you suspect poor root development due to overwatering or other factors, transplanting might not be the immediate solution. Address the cause of the weak roots first. Ensure proper drainage and adjust watering practices. Once healthy new root growth appears, then consider transplanting to a pot with slightly better drainage to encourage further root development.

• Leaves Curling or Browning: Curling or browning leaves can have various causes, not necessarily related to needing a transplant. Investigate potential culprits like nutrient deficiencies, light stress (too much or too little light), or pest infestations. Once you address the underlying issue and the leaves start recovering, you can consider transplanting if the pot size seems inadequate (roots circling the bottom).

• Lights: Light is crucial for healthy growth, but it doesn’t directly determine transplant timing. Ensure your lights provide the right intensity and spectrum for your cannabis strain during the vegetative stage. The distance between the lights and the plants also matters. However, if light intensity is insufficient and the seedlings are stretching excessively, transplanting won’t solve the problem. You’ll need to upgrade your lights or adjust their distance.

• General Transplant Signs: Some general signs your seedlings are ready to move to a bigger pot include developed nodes of 3-5 sets of true leaves, roots reaching the pot bottom where visible roots circle the drainage holes, or if you see slow growth or you see leaves touching pot sides that restrict the airflow.

If your seedlings are experiencing any stress factors, wait for them to recover some strength before transplanting. Transplanting adds stress and a weak plant will struggle to adapt to the new environment.

What is the Importance of Root Development and Patience during Germination?

Strong root development and patience during germination are fundamental for healthy and productive cannabis plants. Here’s why each plays a vital role:

Importance of Strong Root Development-

• Foundation for Growth: Healthy roots act as the plant’s anchor, absorbing water and nutrients from the soil and providing stability. Strong roots allow the plant to access resources efficiently, fueling healthy top growth and maximizing flower production.

• Stress Tolerance: A well-developed root system increases a plant’s resilience to stress. Whether it’s dealing with fluctuations in temperature, humidity, or minor nutrient imbalances, strong roots provide a buffer and enable the plant to recover faster.

• Supports Future Growth: As your cannabis plant matures and produces flowers, the root system needs to keep pace with the increased demands. A strong foundation established early on ensures the plant can support heavy bud development later in the flowering stage.

Importance of Patience During Germination-

• Natural Process: Seed germination is a biological process that takes time. Forcing the seeds or rushing the germination can damage them and hinder their ability to sprout. Patience allows the natural process to unfold and increases the chances of successful germination.

• Variable Germination Times: Different cannabis strains can have slightly different germination times. Some may sprout within a few days, while others might take a week or even longer. Be patient and maintain optimal conditions to allow each seed the time it needs.

• Healthy Seedling Development: Seeds need consistent moisture and warmth to germinate, but not to the point of being soggy or overheated. Patience allows you to monitor the conditions and adjust them if necessary for healthy seedling development after sprouting.

FAQS

1. How to fix stunt growth in plants?

Stunted growth in cannabis plants can be frustrating. There are several factors, and the first step is to diagnose the culprit, like whether your cannabis plant is facing issues due to nutrient issues, pH imbalance, pests, or stress. So, know the problem before you make the adjustments. 

2. In how many days do Cannabis Seeds germinate?

Cannabis seeds typically germinate between 24 hours to 10 days, with an average range of 3-7 days. It depends on germination factors like seed quality, temperature, moisture, and strain type. 

3. Should I transplant my slow-growing Seedlings to a bigger pot?

Don’t rush to transplant slow-growing seedlings! It can stress them further. First, diagnose the cause of the slow growth, like underwatering, overwatering, nutrient issues, insufficient light, or extreme temperatures. Also, if the roots are circling the drainage holes or growth seems stalled despite good conditions then a bigger pot might be necessary.

4. Will slow-growing Seedlings produce smaller yields?

Slow growth during the seedling stage doesn’t mean a disappointing harvest. However, it can affect the final yield. Slow growth limits the time plants have to develop a robust root system and branching structure, limiting the number of buds and yield. The good news is that if you address the cause of the slow growth early and provide optimal conditions later, the plants might compensate with faster growth during the vegetative stage.

5. What are the germination problems with old cannabis seeds?

Old cannabis seeds can be tricky and often have a lower germination rate than fresh seeds. Even if they germinate, it can take considerably longer (up to 10 days) than fresh seeds (typically 3-7 days). The overall success rate with older seeds is generally lower.

6. Why have my Cannabis Plants stopped growing?

Many reasons stall cannabis growth, like nutrient deficiencies or overfeeding, insufficient light intensity or the wrong light spectrum, rootbound, environmental stress, fluctuating humidity, poor air circulation, pest infestations or diseases, etc. The key is to inspect plants and adjust the underlying cause. Once you get things back on track, plants should resume healthy growth.

Take care of your cannabis garden!

Before sowing cannabis seeds, start with the first phase i.e., researching strains and getting healthy quality cannabis seeds from a genuine seller online or offline.

Remember, errors are common and can be subsided if addressed on time. But as we say, prevention is better than cure, so for a successful cannabis harvest, be vigilant, enjoy this phase, and we assure you that it will be worth it!

If you find this article helpful, do let us know!