7 Common Challenges You Need to Prepare for When Growing Cannabis

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Added 08 September 2023

You know how, when you go on a hike, you prepare for the worst by carrying a med kit, an extra bottle of water, some snacks, and letting your best friend know your last location? You know you’re likely not going to run into trouble, but there’s always a chance of something going wrong on the hike — you’re aware of the common challenges hikers face and you prepare against them. 

Why not use the same tactic when growing cannabis? Many cannabis growers run into common problems or challenges when starting out. These problems can range from something as little as a caterpillar gnawing at the leaves to major problems like mold and root rot. Instead of waiting for the problem to occur, it’s time you prepare yourself for it.

Fortunately, the problems are not too many, and, with easy and basic steps, you can navigate easily. Here’s a guide on some of the most common problems you may face when growing cannabis and how to prepare for them as a new cannabis grower. It doesn’t cover all the challenges, but the common ones that you are more than likely to face. 

1. Nutrient and pH-related Problems 

Nutrient and pH-related Problems 

Cannabis is a hungry plant, so you’re going to administer a lot of nutrients to it throughout its growth cycle. These nutrients must be provided in the correct ratios so your plant can utilize them properly. 

However, many variables come into play when feeding your plants, including your soil’s pH, water source, the type of fertilizers you use, the growing medium, quality, etc. Such variables can sometimes lead to problems if you’re not accustomed to feeding your cannabis plant just yet. Let’s take a look at these problems. 

  • pH is Not What It Should Be

One of the most common nutrient problems in cannabis plants is related to the pH of the growing medium. Cannabis prefers a slightly acidic environment with a pH reading between 5.5 to 6.5 in hydroponic mediums while it does well with a range of about 6 to 7 in soil; within this range, the roots can absorb all the nutrients quite easily. 

In some cases, such as salt buildup or poor-quality soil, the pH of the growing medium or rhizosphere may go beyond the recommended range, which is problematic. When the rhizosphere gets too acidic or alkaline, the roots fail to absorb certain nutrients properly; in severe cases, they may fail to absorb any nutrients at all. 

Fortunately, preparing for pH fluctuations is fairly easy. Start by getting yourself a pH pen or meter and measure the pH of the nutrient solution and runoff water regularly. Both the readings should be similar. If the readings are beyond what is recommended, it could be because of two reasons. 

First, if the pH of the nutrient solution is off, it could be because of something messing with the pH. For this, you need to check the nutrient ratios and use a pH up/down solution to correct the pH of the nutrient solution. 

Second, if the pH of the runoff water is very different from that of the nutrient solution, it’s a sign of salt buildup in the growing medium. In this case, you need to flush the growing medium to eliminate the salt buildup and rebalance the nutrient solution to prevent salt buildup in the future.

  • Your Plant Isn’t Getting Enough Nutrients 

Another common nutrient-related problem you may face is when your cannabis plant doesn’t get enough nutrients, leading to nutrient deficiencies. Do not make the mistake of thinking your cannabis plant only needs three macronutrients like NPK; it needs a host of secondary and micronutrients, too. So, you need to ensure you give your plant adequate nutrients of all kinds. 

If you don’t feed your plant properly, your plant may develop nutrient deficiency symptoms like yellowing or dying leaves, spotting, curled leaf tips and edges, stretching, etc. These symptoms are usually caused by incorrect nutrient delivery, pH imbalance as discussed above, and nutrient lockout. 

So, how do you fix it? Give your plant sufficient nutrients; if you’re using store-bought nutrients, always follow the manufacturer’s recommendations over everything else. Next, keep a close eye on the pH and prevent salt buildup in the growing medium, both of which can cause nutrient lockout at the root level. 

  • Your Plant is Getting Nutrient Burnt 

On the other hand, your plants can suffer from excessive nutrients, and you could be at fault here if you take the saying, “the more, the merrier,” a little too seriously. More isn’t always better when it comes to nutrients for cannabis plants. 

Generally, a nutrient burn shows itself via signs like dry or brown leaves, curled leaf tips and edges, or spotting on the leaf's surface. This problem is common for growers who use synthetic fertilizers or supplements since they are fast-acting; organic fertilizers are slow-release and rarely release enough nutrients to cause a nutrient burn. 

Prepare yourself against this by following a strict feeding cycle and keeping an eye on the nutrient ratios and the pH balance of the solution and medium. And if you’re ever in doubt, always be more conservative with your nutrients. This is a relatively easy problem to prevent.

2. Water and Irrigation Routine: Overwatering and Underwatering

Water and Irrigation Routine: Overwatering and Underwatering

Figuring out the right watering routine is another issue that you may face at the beginning of your cannabis cultivation career. And while the issue is easy to fix, it can have long-lasting consequences if you ignore it for too long.

Just like a nutrient burn, overwatering usually occurs when the grower thinks the more water they give the plant, the better it will grow. You’d be surprised at how common this problem is in new cannabis gardens and how bad it can be for your plant. But sometimes, it can also occur due to poor drainage, larger than required container size, or watering the plant during the dark hours. 

Due to overwatering, your cannabis plant can face several consequences, such as drooping or wilting leaves, yellowing, stunted growth, pests, fungal or bacterial growth in the root zone, and eventual death. 

Then there is underwatering, which is far less common but it can still occur if you’re too conservative with irrigation, get a bit lazy, the environment is too hot or dry, or the medium drains too fast. This can make the plant appear weak and even crunchy at times, the leaves wilt or turn fragile, and even the root system may dry up. 

So, how do you prepare yourself for this? Ensure your cannabis plant has enough drainage and the environment is ideal for the cannabis plant. Next, determine the right irrigation interval for your cannabis plant. You can do this by watering the plant and waiting for the medium to half-dry; once the plant begins to wilt slightly, record the time and water it as per that interval.

Another handy trick to use to prevent overwatering is to water the plant when the top inch of the soil is dry and keep watering the plant until 25% of the water drains out of the bottom. Also, choose a high-quality growing medium with good drainage and aeration; you can even improve the same qualities by adding perlite, coco coir, or clay pebbles into the medium of your choice. 

3. Temperature and Humidity Fluctuations 

Temperature and Humidity Fluctuations 

Environmental factors, especially temperature, and humidity, also play a major role when growing cannabis plants and many new growers often run into problems dialing in the correct temperature. The wrong temperature, humidity, or airflow can stress out your cannabis plant, so let’s take a look at how to prepare against such problems. 

  • Keeping the Grow Room at the Right Temperature

Most cannabis strains grow best in a temperature between 75°F to 80°F (24°C to 27°C) during the day and 70°F during the night. So, one of the challenges growers face here is maintaining consistent temperatures.  

Your biggest concern here is keeping the grow room cool; cold temperature isn’t much of an issue unless you live in a cold region. But if the temperatures spike too much, your cannabis plant may experience problems like lower flower potency and aroma, hermaphroditism, foxtailing buds, pest infestation, crispy or brown leaves, etc. 

The best way to prepare for this is to keep an eye on the temperature and use oscillating fans, vents, and perhaps an air conditioner to keep the temperatures in check. If heat stress is a major concern for you, consider investing in a smart thermostat as it can automatically regulate the temperature, taking the stress off your shoulders. 

In some regions, you may face the challenge of keeping the grow room warm, which is relatively easy. All you need to do is use a heater, insulate your grow room, route warm air into your grow room via vents, or rework your lighting setup to utilize their heat. You can even use heating sources like grow tent tube heaters, heating mats, or compost. 

  • Keeping the Humidity in Check

Just like the temperature, the humidity of your grow room is also crucial for healthy plant growth. The right humidity allows the plant to perspire properly and pull nutrients from the ground with ease. 

If the relative humidity is not set right, not only will your cannabis plant find it difficult to produce energy but it can also develop mold and other humidity-related problems. Mold is one of the most dangerous diseases your cannabis plant can face and it can compromise your plant’s yield entirely. We’ll go into the mold as a common problem later on in the article but know that humidity is the leading cause of it. 

Ideally, the humidity in your grow room should be between 65% to 70% during the seedling stage, 40% to 70% during the vegetative stage, and 40% to 50% during the flowering stage. Below are some steps for adjusting the relative humidity of your grow room. 

Here’s how to increase the relative humidity:

  • Spray water manually to increase the moisture content in a jiffy 
  • Keep the soil moist, not wet, to increase the root zone humidity 
  • Turn down the fans in the grow room 
  • Keep a container full of water or damp towels in the grow room 
  • Use a humidifier

Here’s how to decrease the humidity:

  • Turn up the fans in the grow room
  • Water the plant before you turn the grow lights on 
  • Use a dehumidifier

Follow these tips and you can avoid the problem of wrong humidity levels with ease. 

4. Light Stress: Setting the Right Distance 

Light Stress: Setting the Right Distance 

When growing cannabis plants, light stress comes in two forms: low light stress and high light stress. The only way to prevent these problems is by finding the sweet spot of grow light distance from the cannabis plant and using the right type of light. 

Low light stress is less common but can occur if you don’t use enough light. This results in the plant stretching, leaves withering off, and the yield going down drastically. On the other hand, high light stress is more common because grow lights by nature are powerful and, sometimes, too powerful for some plants, which can cause bleaching of the plant. 

The first thing you need to do to prevent light stress is to place the grow lights at the right distance from the plant. It is recommended that you always follow the manufacturer’s recommendations for the ideal distance; and if you are still unsure, use your palm to check the light — place your palm just above the canopy, if it feels warm, move the light farther away. 

The next thing you can try is setting the right intensity of light. A typical cannabis plant requires 308 to 617 μmol of light in an 18/6 light cycle during growth and 460 to 920 μmol of light during a 12/12 light cycle of bloom. Use an online lux to PPFD calculator to figure out how intense your lights are for your cannabis plants. Read our articles on grow lights for cannabis plants to know more. 

5. Mold and Powdery Mildew on Cannabis Plants

Mold and Powdery Mildew on Cannabis Plants

One of the most common challenges you’ll face apart from the environmental factors and nutrition is mold — which occurs in high humidity conditions. Generally, your cannabis plant may face two types of mold issues: powdery mildew and bud rot. 

But rot is when the flowers of your plant start developing mold due to spores. During this disease, the buds may start changing colors, turn brown, seem rotten on the inside, and produce a funky smell. On the other hand, powdery mildew can occur anywhere on the plant and is characterized by white powdery spots that spread farther out over time.

Prepare your plant against mold by keeping the humidity levels in check, as recommended above, and keeping the grow room as clean as possible. Mold is one of the worst conditions your plant can suffer from and it can leave lasting damage. 

If you still notice mold on your plant, remove the infected parts, spray down your plant with neem oil, and give it a mild rinse until all the mold is eliminated. And if the buds develop mold, toss the infected buds — consuming moldy buds is unhealthy. 

A related disease that some cannabis plants may develop is mold rot or slimy roots, which occurs due to a fungal infection in the root zone. This is a deadly disease that can stop the roots from absorbing nutrients entirely and it exhibits symptoms like burnt tips, brown spots on the leaves, nutrient deficiencies, stunted plant growth, drooping leaves, and eventual death.

Bud rot is caused due to excessive heat or humidity, overwatering, dense-growing medium, and poor hygiene. So, the best way to prevent root rot is to keep the environmental factors in check, sanitize the grow room regularly, protect the roots from light, use fresh water, maintain optimum oxygen levels in the soil, and avoid overwatering the plant. 

6. Pest and Pathogen Infestations 

Pest and Pathogen Infestations 

The number of pests and pathogens that your plant can fall prey to is seemingly endless — mealybugs, spider mites, fungus gnats, aphids, slugs, snails, etc. Fortunately, preventing these pests on your cannabis plant before they become a nuisance is easy. 

Here are some tips on preparing your plant against pest and pathogen infestations:

  • Grow companion plants like lavender, sunflower, peppermint, or marigold
  • Introduce beneficial insects that prey on harmful pests; e.g., ladybugs, predator mites, rove beetles, praying mantis, nematodes, etc. 
  • Use homemade neem oil as a precautionary pesticide against pests
  • Or use spinosad, alcohol + water, horticultural oils, or diatomaceous earth 
  • Sterilize the soil or growing medium before each growth cycle 
  • Keep the grow room and gardening tools sanitized and clean at all times 
  • Install pest nets in your grow room vents 

Follow these steps and pests will stay away from your cannabis garden on most days. And even if they do make their way in, companion plants, beneficial insects, and neem oil will take care of them. 

7. Hermaphroditism 


Hermaphroditism or hermies is a condition that develops when a female cannabis plant starts developing male sex organs like pollen sacs as a form of defense mechanism. This problem is common with new growers as this usually occurs when the environmental conditions are not right or the harvest window is extended for too long, causing the plant to enter into survival mode. Sometimes, it can also be genetic. 

While hermaphroditism may not seem like a big problem at first glance, it is dangerous enough to threaten your entire cannabis garden. The female plant produces pollen sacs as a way to pollinate itself, but the pollen can travel to other plants and pollinate them as well. Before you know it, a single hermie plant will have pollinated all the cannabis plants in your grow room. 

The result: cannabis buds with seeds. An entire harvest is compromised. 

So how do you prevent this problem? Start by sourcing your cannabis seeds from reputable seed banks with stabilized genes, especially if you’re growing a non-regular type of cannabis seed. 

Next, provide the right care and environmental conditions to your cannabis plant so it does not enter a survival mode. Figure out everything your particular strain requires to grow well and dial in your grow room to meet its needs. Lastly, don’t wait for too long to harvest — harvest the buds when they are mature.

Summary: 7 Common Challenges You Need to Prepare for When Growing Cannabis

The most common challenges you may face when growing cannabis as a new grower are:

  • Setting the right pH 
  • Giving your plant enough nutrients but not too much 
  • Irrigating your plant at the right time 
  • Keeping the temperature and humidity conditions in check 
  • Preventing light stress of any kind 
  • Preventing mold and mildew on your plant 
  • Keeping the buds off your plant 
  • Preventing your plant from turning hermaphroditism 

Of course, there are many more problems you may encounter in your journey as a cannabis grower — no single growing season is without its unique set of problems. However, these are the common ones and it’s best to avoid these problems when growing cannabis. So, when uncommon problems do arise, you can work on fixing them without having to worry about the basic ones. 

As you have seen above, preventing these problems is as easy as being a responsible cannabis grower. The most common tips across the genre include doing enough research, following manufacturer recommendations, taking good care of your plant, keeping your grow room neat and sanitized, creating a healthy, nurturing environment for your plant to thrive in, and not being lazy. 

Follow the tips mentioned in this article and don’t forget to research aspects that may confuse you. As a new grower, it is easy to get lost in the crowd of information but don’t be intimidated by this. Growing cannabis is a journey and you’ll overcome many fights, so take it one step at a time. The first harvest is never perfect, but it can be pretty good if you take the right steps. 


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