Common Cannabis Seedling Problems New Growers Face

Who says cannabis cultivation is easy? Yes, the plant may be a mere weed, but to grow high-quality plants, you do need to pay attention. Plus, don’t forget that cannabis seeds are expensive and so are all the other gardening peripherals. At the very least, you don’t want to waste your money, time, and energy. 

But sometimes, new growers run into problems even before the plant has grown properly. We’re talking about the seedling stage. What are these problems and what can you do about them? 

Cannabis seedlings can face quite a few issues when they are in their early development phase. These challenges may seem insignificant, but they have a great impact throughout the life of the plant. Hashing out these problems right at the beginning ensures your plants are healthy in the initial days and in the subsequent stages as well. 

You will see some early warnings of seedlings struggling. They may show up in the form of yellow leaves, damping off where the seedlings suddenly just fall down and die, deformed leaves, burnt tips of leaves, and stunted growth. If you take immediate action, the plant may recover but its final size and yield will probably be less.

Seedlings suffer more than mature plants because they don’t have an extensive root system to absorb water and nutrients. They aren't equipped enough to deal with the issues and protect themselves. In addition, pests attack them too. Sometimes, you can't do anything other than watch the plants die. As depressing as that thought may be, it makes sense to prevent such problems in the first place. 

Find out more in this article below where we discuss common seedling problems new growers face and how to fix them.

Growing Cannabis Seedlings

Cannabis seedlings aren’t yet mature; they have just germinated and developed their first set of leaves or cotyledons.  Think of it as the foundation that sets the stage for other phases of growth. Thus, it has a lot of risk of falling ill due to diseases and other infectious contaminants. They require a lot of attention from you because the stage is a make-or-break event for your plant. But, if you neglect it, it can cause some problems which may be hard for the little seedling to recover from.

We can’t stress the importance of growing healthy seedlings. The quality of the seedling affects the quality of the plant throughout the life cycle. Even the yields may not be as good as you expect, as mentioned already. Strong seedlings not only display better resistance to problems including diseases, pests, and other stressors, but they also ensure that you get good yields later. 

Importance of Healthy Seedlings

The development of healthy seedlings in the early stages of a plant's life plays a significant role in the health of the cannabis plant you grow. For new growers, in the sections listed below, we'll explore the common problems and effective solutions to mitigate them for a smoother and quicker transition from the germination stage to vegetative growth. 

But, first, remember that your seeds' quality is paramount, and thus, the first step of any growing operation is choosing the right seeds. Inferior or compromised seeds can result in very poor germination, weak seedlings, or disappointing overall yield.

Conversely, buying superior quality seeds would offer genetic stability, and uniform growth, and decrease susceptibility to diseases and pests. Also, the best kind of seeds will offer the yields you expect. In addition, you can observe a high content of cannabinoids, expected flavors, or the most preferred growth characteristics. Needless to say, this initial expense can prove to be the best investment made in the process of cultivating cannabis.

Tips for Selecting Healthy Cannabis Seeds

Modern cannabis seeds come in diverse varieties. So, it can be confusing to choose the right ones. Keep the following tips in mind before choosing the right seeds:

Physical Appearance: Look for a dark-colored fully-developed seed, with a smooth and intact outer shell while searching for healthier seeds. They should not look light or green; otherwise, you might land up with immature or rotten seeds.

Size and Weight: Go for dense, uniform seeds while searching for a suitable option. Hollow seeds usually don’t germinate. 

Surface Texture: The exteriors of the seeds should be firm to the touch, smooth, and strong. If a seed is cracked or dented, then there might be internal damage.

Source of Genetics: Choose your seeds from a seed bank with a solid reputation. A well-established breeder will give multiple details of the types of seeds it sells and their reputation.

Float Test: Place the seeds in a glass filled with water. The healthier seeds will sink to the base of the glass while the hollow and non-viable ones will float. 

Sometimes, you may do everything right. You can use healthy seeds and they still might not germinate. Let’s find out the reasons. 

Common Cannabis Seedling Problems and How To Fix Them

Seeds may not germinate due to various reasons. Sometimes, they germinate, but they either grow slowly or display stunted growth. Other times, they may just collapse and die. Here are a few common seedling problems you may face while growing cannabis:

1. Seeds Not Germinating

The step that differentiates between a seed and a seedling, marking the birth of your cannabis plant, is germination. This is where the seed sprouts and turns into a seedling, growing a taproot and a couple of cute little leaves. 

Generally, 90% of the seeds sprout. However, if many of your seeds fail to germinate, you may be doing something wrong. Why does this happen? Your cannabis seeds may not germinate for a couple of reasons. 

One, your seeds may have been soaked in water for too long, leading to rot. Two, they may be too old — generally over six months old — and with time, seeds start failing. Third, the soil you are using is too dry, so the seedlings don’t get enough water to sprout. 

How to fix this? It’s fairly easy. If you are germinating your cannabis seeds in the soil, simply soak them for half an hour, which will make the shell a bit softer and allow better moisture absorption.

At the same time, ensure your soil is slightly damp and you must keep it so until the seeds sprout. This is important — even a couple of hours of dryness can reduce the chances of your seeds germinating. 

There are various ways to germinate cannabis seeds. It all depends on the method you choose. Once you get enough experience, you should be able to just soak the seeds for a few hours and plant them in the medium; however, you can also place the seeds between paper towels to trap moisture and wait for the taproots to show up and plant them. 

If you plant the seeds directly in the medium and they don’t germinate after 3-4 days, you can fasten the process by placing a dome on top of the seed to trap moisture again. For this, cut off the bottom of a regular plastic bottle and place it on top of the seeds. You need to keep the cap closed so it holds the moisture inside. 

Finally, the seeds may not be germinating due to incorrect temperatures. Temperature plays a role during the entire lifecycle of cannabis, and germination is no exception. Just like mature cannabis plants need specific temps during the vegetative and flowering phases, you need to maintain consistent temps during the germination process as well. 

Otherwise, the seeds will sprout very late or simply won’t show up at all. If you deviate from optimal temps, which are usually between 74 to 78°F or 23 to 26°C, it can interfere with the enzymatic activity that’s very important for the seeds to germinate. Ultimately, this can lead to unsuccessful germination. Alternatively, you can also use heating mats if required to ensure that the seeds have a warm environment with consistent temps. 

Seed placement in the growing medium and the depth at which you plant them are also critical factors for successful germination. Seriously, you’ll be surprised how many growers get this wrong many times. Incorrect seed placement can lead to various problems where there’s delayed germination or even weak seedlings.

You can’t do anything if you’ve already planted the seeds incorrectly. For instance, you may have planted the seeds too deep or too shallow. It’s best to place them around 0.5 to 1.5 inches inside the soil. Typically, it’s best to make a hole around one inch inside the soil and then place it. However, if you haven’t done it correctly, please don’t dig up the seeds to adjust the depth. Once it’s done, it’s done. You have no option other than waiting and hoping that they will germinate. Although it may take a while, most healthy seeds will germinate without any issues. 

The next time you plant seeds, make sure they are at the right depth in the growing medium. Lightly press the soil or medium over the seed so that there is good contact between seeds and soil.

2. Damping Off

Sometimes, you may notice your young cannabis seedlings suddenly dying off. This is frustrating, and this issue has a name: damping off. This is usually due to the seedlings carrying disease within. 

Some other common causes of damping off include using the wrong type of soil, lack of ventilation, soggy soil, not-so-sanitary conditions, and water from the top. 

Young sprouts are more prone to damping off than seedlings, but it can occur in seedlings, too. Unfortunately, you can’t fix this problem. So, you must do everything you can to prevent this problem in the first place. 

Here are some tips on solving damping off:

• Always purchase high-quality seeds from reputable seed banks and the same applies for the growing medium or starting medium 
• Clean and sanitize any equipment that you will use near your cannabis seedling 
• Use an oscillating fan if you’re germinating the seeds in an indoor environment to increase ventilation 
• Ensure the soil does not get too wet due to overwatering or excess moisture 
• Always water your cannabis seedlings from the bottom 

3. Cannabis Seedling Tipping Over 

Seedling tipping over can be a problem, albeit a not-so-serious one. Generally, seedlings tip over due to the wrong temperature or lighting conditions. For example, if the grow lights are too far or the temperature is too hot; these factors can cause the seedlings to wilt and fall over. 

Insufficient light is as dangerous to seedlings as it is to mature plants. Cannabis plants are usually hungry for light and need a fair amount to perform maximum photosynthesis and survive. That said, seedlings don’t require too much light; however, they will just tip over if you provide very little light. 

The solution is to just provide lights with the appropriate intensity meant for seedlings, which means that it can’t be too high or too low. If you have LED lights that are meant to grow plants from start to finish, you can use them; however, make sure you hang them at the right distance or the seedlings will burn. 

Alternatively, you can use CFL lights until the seedlings grow a little bit with few leaves or at least until they reach the early vegetative stage. You must experiment and find out the correct distance yourself. and give them around 12 to 16 hours of light per day. This should revive a tipped-over seedling, too. 

To treat this, you need to be careful about the lighting conditions and the temperature. As for lighting, you should keep your lamps a couple of inches from the taproots or follow the instructions of the manufacturer. 

4. Overwatering or Yellowing and Drooping Leaves

One of the most common problems new growers face with their seedlings is overwatering. Yes, seedlings do need some water to grow, but too much watering can deprive them of oxygen, causing them to essentially drown. 

This is because the roots breathe and need oxygen; they absorb oxygen via diffusion, and the element is used for cellular respiration to break down sugars into energy. This is why it is crucial that your soil is not compacted when your plant is growing — it allows aeration of the root zone. 

So, what happens when your cannabis seedling is overwatered? You’ll notice your seedlings will start drooping, and if you don’t fix it on time, the leaves will start turning yellow and the plant may eventually die. Even if it does survive overwatering, the seedling may experience pythium or root rot. 

Here are some tips for fixing and preventing overwatering your cannabis seedlings:

Start with the right type of growing medium to avoid issues later. For example, if you choose soil, make sure it is aerated and can drain water easily. If not, add some perlite to the soil. 

Since it serves as the foundation for your plant’s well-being, it is important to purchase soil from branded companies. You can use soil from local nurseries too, but mix in amendments so your plants have enough nutrition to sustain themselves.

Next, don’t let your seedlings sit in runoff water for too long as they hate wet feet. Also, pay attention to the containers you’re using. They must drain well too. If your container doesn’t have holes at the bottom, pierce some holes and then plant the seeds. If not, get fabric bags as they allow the roots to breathe. 

5. Seedlings No Longer Growing 

This is a funky problem to figure out if you are growing a cannabis strain for the first time. Some strains naturally grow a lot shorter than others, making you think they’ve stopped growing entirely. 

However, if you are sure your cannabis seedling has indeed stopped growing, you need to start worrying a bit. This can happen due to various reasons, including cold weather below 65°F (18°C), lack of adequate light, not enough nutrients, or improper watering routine. 

Fortunately, fixing this problem is fairly easy. Use the following tips:

• Ensure the ambient temperature is always over 65°F; you can even use a space heater or a heat mat 
• Invest in high-quality lights if you are germinating the seeds indoors 
• Start feeding your seedlings organic fertilizers as soon as they develop true leaves — liquid compost tea is your best friend here 
• Water your seedling properly — neither too little nor too much 

6. Leaves Curling Up 

If your seedling leaves suddenly start curling up, it’s an indication of a serious problem. Usually, if a seedling’s leaves are curling up, it eventually dies. 

Curled leaves in seedlings are caused by three primary reasons: webbing or pests on the leaves, underwatering or dehydration, and chemical nutrient burns. 

Unfortunately, it’s difficult to save a seedling at this stage, but you can take some steps to prevent this problem in the first place, such as the following:

• If you spot any pests on the seedling, immediately use neem oil or insecticidal soap to eliminate them before they start causing any trouble. However, neem oil may be too harsh on seedlings, so dilute it as much as possible and then use it
• Avoid using chemical fertilizers that are too strong; instead, use compost tea, seaweed, or liquid fish 
• Don’t let your soil completely dry out; water it as soon as the top inch of the soil is dry 

7. Bugs Around the Seedling 

Pest infestation is annoying and nasty, and unfortunately, it does not discriminate between seedlings and fully-grown plants. Sometimes, common cannabis pests can wreak havoc on seedlings too. 

Again, this problem occurs if the soil is too wet and the grow room isn’t clean and sanitary. This can attract various pests like spider mites and fungus gnats, which may come in a small number but quickly multiply and destroy your delicate cannabis plant. 

The best way to deal with this is to use neem oil or insecticidal soap to eliminate them, sticky traps to trap them, and keep your grow room clean and isolated to prevent them from entering in the first place. 

Fungus gnats usually come when the soil is wet. Thus, the best way to prevent them is to water the soil properly and avoid overwatering. 

Out of all the pests that can harm cannabis seedlings, you should be particularly aware of cutworms or caterpillars. Cutworms are a type of caterpillar that look plump and wriggle around the soil. Typically, they emerge at night to feed on plants, but they love young seedlings the most. 

If cutworms attack your seedlings, you will notice that the stems are weak and damaged. Or, the plant may just disappear as these pests chew off the stems. If they have eaten the plants, there’s nothing you can do. If the item is damaged to a small extent, you can support it with a small stick and wait until it recovers. 

To be honest, you must look for ways to prevent cutworms in the first place as the damage is usually irreversible. If you’re growing outdoors, you can place barriers or collars around the seedlings to prevent access to cutworms. Of course, you can do the same indoors as well. However, if the pests are already in the soil, it becomes pointless. 

Another way to prevent these pests is to use natural predators like parasitic wasps or beetles that feed on cutworms. You could also introduce beneficial nematodes that prey on the larvae of cutworms, thereby disrupting their population. 

Some growers use diatomaceous earth by sprinkling it on the soil. As it is abrasive, it can kill pests with soft bodies. However, this won't work when the soil is wet. 

Finally, if you have some space and are willing to put in the effort, you can plant companion plants like nasturtiums and marigolds that act as pest repellants around the cannabis seedlings. 

Always keep a lookout for cutworms if you spot one wriggling in the soil. Make sure you check the leaves at night time as these pests are nocturnal. If you spot them, handpick and remove them. 

8. Shell Stuck on the Seedling 

Sometimes, you’re just unlucky. And during such times, your seedling may have the seed shell stuck on it. This may look silly at first but it’s a problem you need to fix asap. A stuck shell can prevent the seedling from developing properly and can even lead to seedling stretching. 

Generally, this happens if the conditions are not humid enough for your seedling. So, start by hydrating the seed shell — spray down the seedling with plain water. If you don’t want to do that, you can even drop a few drops of water on the shell with a dripper tool. The shell should come off. 

Next, take a close look at the same location where the shell was stuck. Sometimes, the membrane can remain behind, which you can remove with your fingers or a pair of tweezers. If you have to do this, be super careful since your seedling is very fragile at this stage. 

9. Nutrient Burn or Overfeeding

One of the most common issues growers face with seedlings is nutrient burn. When your seeds germinate, you have this profound urge to help them grow into mature plants as soon as possible. Therefore, you do everything possible to achieve this, including feeding large amounts of nutrients. 

Of course, you may think that you’re using fewer nutrients, but since seedlings are still small and don't have the capacity to intake too many nutrients, it’s easy to overfeed them. 

On the other hand, it’s possible that cannabis seedlings also suffer from nutrient deficiencies that can occur when the medium you provide has absolutely no nutrients. However, nutrient deficiency is rare in seedlings as the cotyledon has enough to feed the plant until it develops a few true leaves. 

As you can understand, two things can happen: either the seedling faces a nutrient deficiency after developing a few leaves or it experiences nutrient toxicity due to overfeeding. 

It’s pretty easy to solve nutrient deficiencies if you take action immediately. As soon as you see the seedling develop a yellow hue, make sure you evaluate the type of fertilizer or medium you’re using. When nutrients are lacking, the plants have problems and do not perform as they should; potential yields are lost, but when left unchecked they can seriously reduce a cannabis plant's potential. 

As for nutrient burn, it can be hard to fix, especially when the plant is very young. Nutrient toxicity stresses the plants a lot and any stress at such a young stage can be detrimental. 

Also, this doesn't happen only with hydroponic plants. Even seedlings in organic soil can easily develop nutrient toxicity. For example, one of the most popular types of organic soil growers use to grow cannabis is super soil. This is something you can do at home. Most growers follow all the instructions and mix in all the necessary ingredients to make the soil; however, the most important step lies in letting the soil “cook” at the end of it. It needs at least 30 days for the organic matter to break down. 

Remember, It also depends on the type of ingredients you're using. For instance, if the manure you’re using is very raw, it is highly likely to burn the plants. However, even if you use well-aged manure, you should let the soil cook for a while. If you try to speed up the process and skip this step, the young seedlings will not be able to take it. As a result, they display leaves with burnt tips. 

Nutrient burn is pretty easy to spot too. Not only will the leaf tips look burnt, but they will also look crispy at times. You may also see various discolorations. To fix this, the only solution is to stop feeding the plants. Make sure you water them with plain pH-balanced water and wait for the plants to recoup. Although the old damaged leaves will not revert to their original healthy state, the new leaves will be fine. If not, adjust the nutrients some more and repeat the process. 

To avoid these problems, it’s best to start with a quarter-strength of the recommended nutrient dosage especially when you’re feeding seedlings. Keep an eye on the ppm and maintain a range of about 100-250 for seedlings in the soil while 300-400 should work for other mediums like coco. 

Summary: Common Cannabis Seedling Problems New Growers Face

Taking care of seedlings is a delicate process, and it can come with various problems if you’re not careful enough. Fortunately, it’s fairly easy to avoid these problems as long as you are mindful about your cultivation. 

In essence, you need to treat your seedling like a baby; it’s delicate, so don’t be rough with it, give it water and nutrients on time and in the right quantity, and make sure it is comfortable with the temperature and relative humidity levels. And regularly check it for any signs of problems or pests.

Follow these steps and you won’t even notice when your cannabis seedling has turned into a lush plant. Then, it’s only a matter of time before the plant starts rewarding you with tasty buds.