Weed Seed Growing Slow

If you feel like your plants are not growing as fast as they should then it’s most likely there’s something wrong, slow growth can be a result of a Have you come across stuntedplant? Learn how to identify the causes and how to take action to accelerate cannabis growth. Continue reading the article! When your cannabis plants are growing slow or not at all, there is a reason for it. Find out about the top 10 reasons for slow cannabis growth.

How To Deal With Slow Cannabis Growth

If you feel like your plants are not growing as fast as they should then it’s most likely there’s something wrong, slow growth can be a result of a number of things. If your plants are suffering from slow root growth, or you’re asking yourself why your plants are growing so slow, here are a couple of tips to help you fix your problem, remember these problems can affect cannabis in all stages of plant growth.

When growing cannabis there are a lot of variables that can affect the growth and final result of your harvest. From genetics, possible nutrient deficiencies, root system, and pests problems to the environment, you need to make sure everything is okay if you want to have a smooth growth cycle. Providing your plants with a warm slightly humid climate will not only help you to deal with their slow growth but can result in a bigger and better harvest.

1. Lights

Not enough light is one of the main problems associated with slow growth. Not providing enough light will cause your cannabis to take way longer to develop because they don’t have a good amount of light to photosynthesize. When your plants are still young you can see this, for example, when your seedling is stretching too much, this is a sign that your plant is not getting enough light and is trying to get closer to it.

Now, have in mind that you can also give your cannabis too much light (if the environment is not appropriate for the amount of light you’re providing). This happens because most high-intensity lights have to be used in combination with higher CO2 levels so your plant can absorb the light properly, if the CO2 level is too low your plant can get stressed and show heat stress signs, resulting in slow growth.

How to deal with it

If you’re experiencing light-related problems (like heat stress symptoms), you should try to adjust the intensity (with a dimmer) or the height your light fixture is at. A good way to test this is to keep your hands under the light for around 30 seconds, if it’s too hot for you, it definitely is too hot for your plants.

As a general guide, LEDs should be kept between 60-100 cm from your plants (depending on the model) while light bulb fixtures should be around 30cm from your canopy.

Incorrect Light Spectrum

The light spectrum will also affect plant growth so you need to make sure to use the right spectrum for each stage of plant growth. This doesn’t mean your plants won’t grow under a different spectrum but if you want your plants to grow fast and healthy, make sure to provide a blue spectrum during the vegetative stage and a red spectrum during the flowering stage.

Interruption of the Light Cycle

Photoperiod cannabis is really sensitive to light leaks during the light cycle. You always have to there are no holes in your tent where light from the street lamp, for example, could leak in. Light leaks can not only turn your plants’ hermie but can also cause a hormone imbalance that could reveg your plants, which will end up extending your grow cycle, and affect yields and quality. So if you’re having issues with light leaks make sure to check out autoflowers as they are not affected by light leaks because they flower based on age and not the light cycle to do so.

2. Stress From Accidental Damage

If your fan or light fixture accidentally falls over your cannabis, there could be some serious problems such as broken branches or even worse, and this can slow down growth significantly. When any type of damage occurs, your plant will have to move around nutrients and vitamins, for example, to the areas that need it the most, meaning that your cannabis will redirect the resources needed for new plant growth to repair the damage.

In most cases, your plant will most likely slow down growth for a couple of days until it finished recovering and can continue growing normally. Just remember that seedlings are super fragile so double-check the equipment and make sure everything is hung up properly before starting your grow cycle.

How to deal with it

There’s not much you can do if your cannabis has suffered an accident, so first make sure you know what caused it. If a branch snapped due to strong winds you can use bamboo stakes or a scrog net to provide support; If a piece of equipment fell on your cannabis and broke a branch, all you can do is try to fix it with duct tape to help it hold it in place until it heals and check the equipment before starting your next grow cycle.

3. Low-Stress Training

Plant training is used by almost all cannabis growers to adjust plant growth and end with the best results possible in a specific grow setup but it may end up having the opposite result if done too aggressively and slow down growth. As the name says, low-stress training will stress your cannabis, but not as much as high-stress training, this allows you to do it more often if needed, but you will have to keep an eye on your plant and keep good conditions to minimize stress.

LST is an easy and effective way of molding plant growth to your grow tent but even minimal training such as pruning can be bad.

For example, pruning a lot at a time or very frequently will cause your plant to slow down growth in order to recover and this can be very bad, especially with autoflowers because it may end up stunting growth for days or even weeks, so make sure you do it gradually and carefully.

This also applies to tying down the branches or simply organizing the canopy under a scrog net, if you apply too much pressure or tie the branches too tight you may end up hurting your plant and this will cause stress so make sure you do it carefully.

How to deal with it

Luckily, it’s can be easy to help your plant recover from slow growth, f you’ve pruned too much there’s not much you can do other than making sure the growing conditions are on point to allow your plant to recover faster but, if you were LSTing and the ties are too tight, you can remove them and tie them again, paying attention to what you’ve done incorrectly before to avoid doing it again.

4. High-Stress Training

You can end up damaging your cannabis with low-stress training techniques as well as with high-stress training techniques, although it may be easier to damage your plant with HST because it literally consists of mutilating your cannabis plant.

High-stress training consists of mutilating your plant so always make sure your plants is healthy before performing it.

Now, this doesn’t mean that your plant will only get stressed if you mutilate it, as said above you can also stress your cannabis with low-stress training.

Just remember that HST will always slow down growth because you are cutting away a part of the cannabis plant so make sure you do it early rather than late and that the conditions are on point so your cannabis can recover fast and continue growing normally.

How to deal with it

Now, when dealing with the recovery period after LST or HST, the only thing you can do is provide the best growing conditions possible to boost the basic processes such as transpiration and photosynthesis, this will allow your plant to recover faster.

If you’re not sure what the conditions should be, you can always take a look at a VPD chart to ensure you’re providing what your cannabis needs but other than that, it’s just a matter of seeing how your plant reacts and maybe not performing any training if your plant is in bad conditions.

See also  Weed Seeds For Sale In Us

5. Environment

Even though some plants can withstand harsh environments, most cannabis plants enjoy a warm slightly humid climate, it’s essential you have a thermo hygrometer to measure this and adjust when necessary and avoid stunted growth. If the temperature in your grow room is below 15°C or above 30°C for too long, you will start to see slower growth and if left like that for too long, you’ll see signs of unhappy cannabis like droopy leaves or the leaves starting to yellow, crisp and die.

The ideal humidity levels are around 60% for seedlings, 50% in the vegetative stage and 40% in the flowering stage.

This also applies to humidity. Humidity levels below 35% can stunt growth and if they’re even lower than that (around 25%), you’ll start to see signs of deficiency on your plant.

A humidity level higher than 70% can also have a toll on your cannabis plant, slowing your plant’s growth, making them droopy because it makes it harder for the plant to move water internally.

How to deal with it

If your seedlings are not growing or you’re wondering why your seedlings are growing so slow, this could be the problem. To avoid environment-related problems you have to ensure your growing environment is optimal for your cannabis.

For your cannabis plants to thrive you need to provide a temperature of around 22-25 celsius and a humidity level of 60% for seedling, 50% in the vegetative stage, and 40% in the flowering stage.

Stage Humidity Level
Seedling 60%
Vegetative 50%
Flowering 40%

These numbers are just a guideline, you should always look for the signs your plants give you and adjust the environment accordingly.

6. Root problems

Unless you’re growing in a hydroponic (or aeroponic) setup you won’t be able to see your plant’s roots.

Keeping a good environment for your cannabis also includes maintaining the medium oxygenated and with the right amount of water. Root problems are the main cause of slow growth with new growers, adjusting and maintaining a good growing medium for the roots is the best way to fix stunted growth in plants. The lack of appropriate care with the roots can cause the following problems:


Overwatering is a common occurrence with new growers, excessive watering inhibits oxygen from reaching the roots and can result in the drowning of your plant.

Overwatered plants will start to droop, show slower growth, start yellowing, and show signs of deficiencies because they can’t absorb nutrients properly.


Underwatering isn’t as common as overwatering but can also affect your plant in a bad way.

If there’s a lack of water in the medium, your plant will show signs similar to the signs of overwatering but instead of the leaves looking “fat” because of the excess of water, they will look thin and fragile because there’s no water (or a tiny amount) in them.

Oxygen is essential to the roots, by providing the appropriate amount of oxygen in the medium, you allow the roots to develop healthy, resulting in a healthier plant.


Rootbound happens when you plant your seeds in a small pot or container and the roots don’t have any more room to grow. When this happens, your plant will start to show different symptoms that can confuse you, when you see your plant getting much wider than the pot you should start thinking about transplanting it, failing to give the roots the space they need to grow will result in droopy leaves and other signs associated with overwatering of nutrient deficiencies.

How to deal with it

To avoid root problems you have to make sure you’re giving the roots enough oxygen, room to grow, and water only when needed. You should water only when at least 60% of the medium is dry and transplant your cannabis when she’s growing out the pot she’s in. If you’re having problems with this we recommend you try different mixes of soil, perlite, and coco fiber, this will help you provide the right amount of oxygen and water to the roots.

7. Nutrient deficiencies

Plants need nutrients to grow, depending on the medium you’re growing in, you’ll need to not only provide all the macronutrients but also a good amount of micronutrients. You also have to remember that nutrient absorption is directly related to the pH level.

If you don’t provide the amount of nutrients your plant needs or if you fail to adjust the pH level your plant won’t be able to grow properly and will result in nutrient deficiencies, stunting growth, and damaging the leaves.

How to deal with it

To fix this you need to adjust the amount of nutrients you’re giving your plant and check the pH level every day.

If you’re giving the right amount of nutrients then the problem will most likely be the pH level, remember the pH level changes according to the medium you’re growing in and you should always check it and adjust it if you want your cannabis to grow healthy. It is crucial you keep your plant well-fed and with the correct pH levels, if you see even the slightest yellowing on the leaves then your plant is most likely not growing properly.

8. Bugs or pests

Bugs and pests feed on your plant, they can feed on the sugars or on the plant matter, either way, they will damage your plant and slow its growth. Some bugs like Spider mites can also rot the buds, making them unhealthy to smoke so it’s crucial you keep your plant healthy and check on them every day to spot bugs early.

How to deal with it

There are different ways to deal with bugs but the best way is to prevent them.

By checking on your plants every day you avoid bugs, you can also spread yellow sticky traps so you can spot them early.

You can also spray your cannabis with a mix of water and a small dose of organic insecticide to prevent them although this is not recommended, insecticides should only be used when you already have bugs and are used to eliminate and not to prevent them.

9. Genetics

Slow plant growth can also be the result of bad genetics, even though you cannot change this once you’ve already started to grow your plant, you should always start with good genetics. This will save you time and money and can result in a bigger and better harvest.

How to deal with it

If you’re dealing with slow plant growth and can’t seem to get to the root of it, the cause of your problems can be bad genetics. If you want a plant that really thrives and grows perfectly we recommend our new Gorilla Cookies Auto.

I got 134g off this gal growing in 3 gal pot with 24 hours of light. i’m stoked with the result! Smells like diesel. Was a great grow overall.

This strain is very easy to grow and can produce up to 600gr/m2 of extremely resinous buds with basic maintenance, so with basic care you can end up with a great harvest.

10. Incorrect pH Levels

Incorrect pH levels are probably the most common reason for slow growth. This happens because cannabis plants can only absorb nutrients in a specific pH range so if the pH levels are incorrect your plants will not be able to absorb food, even if it’s present in the substrate.


In order to fix this, all you have to do is check and adjust the pH levels, but this depends on the specific substrate you’re growing in. Remember that you will also need a pH Up or pH Down solution, but all you have to do is adjust the pH to 6.5 – 7.0 in soil, 5.6 – 5.8 in hydro, and 6.0 – 6.3 in coco fiber or soilless grows.

11. Pot Size

In general, growers start seeds in plastic cups and transplant them to bigger pots as the plants grow but starting your plants in super big pots can cause several problems such as overwatering as the substrate which will retain much more water than your seedlings can absorb. SO to avoid problems like this, make sure to start in smaller pots or plastic cups and only transplant them to a larger pot once they have big enough. In general, you should only transplant a young plant into a 7-liter or bigger pot once they have developed at least 5 pairs of true leaves.

See also  Botanical Gardens Weed Seeds

As mentioned, the only way to avoid this is to use the right pot size, so once your seedling is big enough, follow the table below and make sure to transplant directly to the right pot in order to avoid any issues.

Recommended Pot Size Based on Plant Size
Pot Size Plant Size
3 liters 35 – 50 cm
5 – 7 liters 60 cm
8 – 10 liters 100 cm
12 liters +130 cm

12. In Conclusion

It’s fairly common to deal with cannabis stunted growth, especially if you’re dealing with a cannabis seedling growing slowly. Slow plant growth, either slow cannabis flowering or vegetative growth, can be the result of a not-optimal growing environment or even a mix of some of the elements said above.

So if you’re dealing with cannabis slow growth or if you’re having problems with your plants, we recommend checking every one of the topics we talked about and if you cannot solve your problems try to grow good quality genetics in your growing cycle. This can not only solve your problems but surprise you with the results you’ll have.

What to do when cannabis plants don’t grow or when the growth is stunted

Find out how to identify the causes of stunted growth in cannabis plants and how to correct them.

It can be challenging to determine the causes of this phenomenon, even if the plant concerned is a cannabis plant.

It could be insufficient or excessive feeding, lousy lighting or who knows! Maybe the marijuana seeds are the problem as it is not always easy to find quality ones.





In this article, we want to help you understand why the plants are not growing and how you can remedy this. Note, however, that the cultivation of cannabis in the UK is illegal.

Here is what happens when the plants do not grow or grow too slowly.

Why don’t your cannabis plants grow?

When a cannabis plant does not grow or grows only very slowly, there is always a reason behind.

If you are not a cannabis expert, it can be challenging to understand if it is environmental factors, if there are problems with nutrition or perhaps light and temperature, especially if the plant’s growth stops suddenly or at the beginning of the harvest.

Many people wonder what to do with plants that do not grow tall, how a self-flowering plant could block itself from flowering and how to fix this.

When faced with this type of problem, it is essential to have a general idea of the situation. It would help if you tried to have some data at hand and, in particular, to clarify what you have done before that.

With the list of cases and remedies that follo, it will be easy to understand whether a plant with reduced growth has suffered damage or whether the problem is due to the cannabis seed.

Let’s start with the former reason.

Slow growth? Pay attention to the seeds’ quality.

If the cannabis crop grows slowly or too slowly when using auto-flowered or feminised seeds, it usually depends on the poor quality of the seeds you purchased.

It is not only crucial that you opt for good genetics. It is also essential to avoid seeds that are too old.

For example, BSF cannabis seeds you will find for sale on SensorySeeds.com have been selected for quality and age, while the seeds that are sometimes bought without too much attention, perhaps belong to slow strains that cannot guarantee a good yield.

The secret is to count on a reliable seeds bank.

Poor lighting can block or slow down the growth of a plant.

In addition to carefully choosing good cannabis seed genetics, it is also essential to pay attention to the plants’ light intake. Light is a fundamental element that regulates various developmental processes and can lead to stunted plant growth, whether it is low, too high or wrong.

If you believe that your cannabis plants do not receive enough doses of light, the solution to indoor growing is to move the lights closer to the apical part of the plants. On the other hand, it is necessary to place the plants in a brighter and sunnier environment in outdoor cultivation.

Excessive exposure can also cause stress to the plants and slow growth, especially in young plants.

It is important not to rush and respect the rhythm of the plant not pushing its growth by methods that may be counterproductive. To reduce the time from sowing to harvesting, you can opt to buy fast-flowering seeds to shorten the date of the first phase.

This said, if you think that your cannabis plants in indoor cultivation are subjected to high doses of light, it is best to move the lamps away from the apical parts of the plants and reduce intensity. Outdoors, likewise, it is advisable to move the plants to where the light is less direct and more diffuse.

Plant with atrophied growth due to too much water.

However, in a plant with atrophied growth, the motivation often falls on excessive watering.

When marijuana plants are given too much water, this can lead to the rotting of the roots with the multiplication of fungi and other micro-organisms, and nutrient defects.

If the plant is not healthy and does not receive the proper diet, it is expected not to grow as it should.

Mainly when excessive water damages the roots, it affects the oxygenation of the plant and thus slows down the metabolic functions so that the growth of the plant not only could slow but might definitely stop.

Ideally, a plan that is adapted to the plant’s growth phase should be followed. You should also check if the soil remains too wet and cannot dry out between waterings.

Plant malnutrition: growth slows down when nutrients are too little or too much

To thrive and grow steadily, cannabis plants must have all essential nutrients.

The usual soil can only guarantee these nutrients for 3 or 4 weeks, after which fertilisers must be used. In this sense, it is necessary to be careful with the doses. Indeed, cannabis plants cannot get rid of excess nutrients, which can lead to poisoning.

On the other hand, if nutrients are scarce, growth is naturally slowed down by the lack of “fuel”.

Parasites and insects: if the plant does not grow because it is exploited and damaged.

After all, insects and pests can be the cause. Some feed on sugar, some on the plant itself, and some damage the plant so much that growth is stopped.

In this case, it is essential to intervene as soon as possible by identifying exactly which enemies need to be controlled for the plant’s well-being.


You now know why sometimes you have to deal with plants with stunted growth.

If you are wondering how to accelerate the growth of your cannabis, the answer is to identify the problems mentioned above and apply the appropriate solutions.

We remind you that cannabis cultivation is not allowed in UK and Europe, but who knows … maybe this article could help you if and when the laws will change.

For now, buy the best cannabis seeds online and choose from feminised BSF seeds, BSF fast-flowering seeds and many other strains to collect them!

Top 10 Reasons For Slow Cannabis Growth

There can be many reasons why your cannabis plant is growing slow or has stopped growing altogether. It could be a factor in your growing environment such as temperature being off, a problem with nutrients, or something else. Let’s look at the top 10 reasons behind slow and stunted cannabis growth.

See also  Cookies Weed Strain Seeds

When you are growing cannabis, you may sometimes think that you have taken care of everything. Then, seemingly out of the blue, you notice that your plant has stopped growing or is only growing slowly. This can happen during all stages of your cannabis plant’s growth—early in the seedling stage or later in the vegetative growing phase. Why won’t your seedling grow? What could be the reason for your cannabis plant developing slower than it should? Here are some of the most common reasons for slow and stunted growth.



Many cannabis growers, especially those new to cultivation, tend to overwater their plants. Overwatering is indeed one of the most common (and lethal) mistakes when it comes to growing weed, and can cause many growing problems as a result. Slow and stunted growth of your plant can be due to nutrient deficiencies, root rot, or infestation, all of which can be catalysed by excess water in the substrate. If you want to water your plant right, don’t do so on a schedule—just when your plant needs it. It is always better to water less often so that the soil can dry out. A good test of whether you should water your plants is to lift the pot. If the pot is heavy and damp, it’s not time; if the pot is light and dry, you’ll know it’s time to water.


Some cannabis growers have a tendency to overfeed their plants, but not giving plants enough nutrients is another culprit of slow growth. If you’re growing with a pre-fertilised potting mix, know that the nutrients in these will normally only last some weeks to a month. After that time, you need to administer your cannabis with phase-specific nutrients to support healthy development, and eventually, robust flowering. However, know that nutrient requirements for your plant can vary. This will depend on the strain that you’re growing, as well as other factors such as temperature and how much light your plant is getting. If you’re growing under intensive grow lights, your plant will need more nutrients than if it were growing under less light.


Low-quality or old cannabis seeds are a common reason for all sorts of growing problems. If you use low-quality seeds, your plant may grow slow and stunted, or your seed may not even germinate at all. For best results, choose only quality seeds like those you can get at Zambeza and other reputable seed banks. With Zambeza Seeds, you will receive the best genetics so your cannabis plant will have a great start to its life, and a much better chance of healthy growth throughout all stages.


Cannabis needs a lot of light, especially in the flowering phase. But your plants will also need sufficient light to support their vegetative growth. Although light requirements may vary between strains, all plants need a baseline amount of light exposure to prosper. If you grow indoors and feel that your plants are not getting enough light, you should be able to simply lower your lights, decreasing the distance between the lamp and the canopy. If you’re growing outdoors, make sure you plant in a spot with a lot of direct sun, or move your pots around throughout the day to maximise sun exposure.


Again, cannabis plants love and require a lot of light; but too much is not a good thing either. Constant direct exposure to intensive sunlight or high-intensity indoor grow lights can stress your plants, which can lead to slow growth and other problems. If you think that too much light is behind the issue and you are growing indoors, move your plants further away from your lights to decrease the intensity. If you’re growing outdoors in pots, move your plants to a location with diffused or partial sunlight if possible.


In addition to the amount of light, the spectrum of light plays an equally important role. Some types of grow lights, those with a warmer, more reddish light spectrum, are more suited for flowering, while other lights can emit a colder, blueish light that is better for the vegetative phase. Make sure that you use a light in the right spectrum, otherwise your plant may grow slower than normal. Many common grow lights today are suitable for both your plant’s vegetative and flowering phases. However, if you are not sure, make sure you read the description for the light or ask the vendor before you purchase.


Cannabis requires many vital elements for healthy growth, and calcium is one of them. If your plant is experiencing a calcium deficiency, it will mostly affect new growth on top of your plant. You may observe symptoms such as slow or twisted new growth, or the leaves turning purple or yellow. In time, your whole plant will take on a sickly appearance.

Although most cannabis nutrients should contain adequate amounts of calcium for healthy growth, a deficiency can still occur. Some growing media such as coco increase the risk for a calcium deficiency. This is also why coco growers normally use special coco nutrients or add Cal-Mag products to their nutrient regimen. You can also add dolomitic lime to your soil to avoid a calcium deficiency.


Along with overwatering or overfeeding, problems with the pH value of the water or nutrient solution are a common reason for slowed growth. Cannabis is rather picky when it comes to correct pH value, and if your plant is not within a healthy pH window, it cannot take up nutrients—even if they are present.

If you grow your cannabis plant in soil, ensure that your water or nutrient solution has a pH value of 6.5–7.0. For hydro, the optimal pH for cannabis is 5.6–5.8. If you grow soilless, including in coco, make sure the pH value for your water sits at 6.0–6.3.


Have you ever wondered why you should start your plant in a small pot and only later repot into a bigger container? The answer is that a tiny seedling cannot absorb all the moisture present in a large pot, which can lead to all sorts of troubles. Mature plants with a large root system won’t have this problem as they can drink much more. One other issue with large pots is that they will take much longer to dry out. And just as with overwatering, the large pot and the stagnant moisture can incite slowed growth and a host of other problems.

Always start your seed in a small container such as a cup or jiffy pot, then transfer it into a larger pot once your plant has a set of 5–6 leaves. If you have already planted your seed in a large pot, make sure that you water only in a small area around the seedling.


Plant height 30cm: 7.5–11l container
Plant height 60cm: 11–19l container
Plant height 90cm: 18–26l container
Plant height 120cm: 22–37l container
Plant height 150cm: 30–37l+ container


Cannabis, like many other plants, grows best at moderately warm temperatures. The optimal temperature range for growing weed is between 25 and 30°C, although nighttime temperatures should be a few degrees lower. If it is too cold, this will slow down your plant’s growth. Likewise, you want to avoid exposing your plants to excessive heat. Temperatures that are too high can also lead to slow growth or halt plant development altogether. If you are growing indoors, make sure that the temperatures are at a comfortable level for your plants and that your grow room is well-ventilated. Sometimes a simple fan can be all that’s needed to get grow room temperatures under control.

No reason to panic if your cannabis plant is growing slow! With our guide, you should be able to identify and address the most common reasons for slow and stunted growth.