From rot to resilience: How to fix root rot in cannabis

Rotting roots of a plant suffering from root rot

Hey there, fellow cannabis growers! Need to know how to fix root rot? Look no further! Welcome to our guide on fixing root rot and ensuring the health and vitality of your precious cannabis plants. 

We all know how disheartening it can be to see your plants suffer, but fear not! In this article, we’ll dive deep into understanding root rot, identifying its signs, implementing prevention strategies, and treating it effectively. So, grab your gardening gloves and let’s get started!

What is root rot?

Before we jump into how to fix root rot, let’s take a moment to understand what root rot is all about. It occurs when the roots of your cannabis plants become infected with harmful fungi, leading to their decay. 

But how does this happen, you ask?

Things such as overwatering, poor drainage, and lack of airflow can create the perfect breeding ground for these fungi. This wreaks havoc on your plants’ roots. And we don’t want that, do we?

What does root rot look like?

The easiest place to spot root rot symptoms is the roots themselves- the name gives it away, right!? But there are other signs of root rot to look out for too. If your plant has root rot it may display some of the following:

  • Mushy or discoloured roots. 
  • Wilting leaves, 
  • Stunted growth, 
  • Yellowing or browning of leaves, 
  • A foul odour emanating from the roots,

If you notice any of these symptoms, it’s time to take action!

Can root rot spread?

Yes! Unfortunately, the fungal spores can become airborne. This means that it’s easy for the problem to spread to your other indoor plants. Similar to other pests and diseases such as white aphids. Root rot can also be spread by travelling on tools or equipment so keeping these clean is important. 

Preventing root rot

To prevent your plants from becoming susceptible to root rot, it’s essential to maintain regular prevention methods.  

Maintaining proper drainage:

One of the key factors in preventing root rot is ensuring your type of soil or growing medium has excellent drainage. Consider adding soil amendments like perlite, coco coir, or vermiculite to your potting soil to improve drainage. Look at the table below for a quick summary of recommended amendments:

Soil amendmentBenefits
PerliteEnhances aeration and drainage
Coco CoirRetains moisture while promoting drainage
VermiculiteImproves water retention and drainage properties

Optimal watering practices:

Proper watering is crucial to avoid overwatering, a common cause of root rot. Remember to water your plants when the top inch of the soil feels dry. Avoid a soggy environment by allowing excess water to drain away. Here are some watering tips to keep in mind:

  • Water your cannabis plants slowly and evenly.
  • Avoid watering the foliage, focusing on the base instead.
  • Use your finger or a moisture meter to check the soil’s moisture level.
  • Adjust your watering frequency based on the plant’s needs and environmental conditions.

Adequate air circulation:

Your cannabis plants thrive when they have access to fresh air. Ensure proper ventilation in your growing space by placing fans strategically. This helps reduce humidity levels, preventing the growth of fungi that cause root rot. Go ahead, let the breeze in!

Sanitation and sterilisation:

Maintaining a clean and sterile growing environment is vital. Regularly clean and sterilize your gardening tools, pots, and containers to prevent the spread of harmful pathogens. Remember, an ounce of prevention is worth a pound of cure!

Evidence of root rot damage

How to fix root rot

Diagnosing the severity:

When dealing with root rot, it’s important to assess the extent of the damage. Take a close look at the roots of your affected plants. Are they partially or fully decayed? Understanding the severity of the issue will guide you in applying the most appropriate root rot treatment.

Step-by-step treatment process:

Remove affected plants:

Gently remove the plant from your growing area to prevent the spread of the disease. Dispose of severely damaged, dead or dying plants. If a plant looks as though there’s still a chance of recovery, isolate it from healthy plants.

Trim affected roots:

With clean and sterile tools, carefully trim away any mushy or discoloured roots. Make clean cuts, remove the damaged sections, and leave behind healthy root tissue. This will help your plants focus their energy on regrowth.

Apply beneficial microbes and fungi:

Introduce beneficial microorganisms and fungi to promote root health and combat the harmful pathogens causing root rot. You can find specialized products or even create your own homemade remedies. You can make your own microbe solution using mycorrhizal fungi or beneficial bacteria like Bacillus subtilis. These superheroes of the soil will work their magic!

Adjust Watering and Nutrient Regimen:

While your plants recover, it’s important to adjust your watering and nutrient schedules. Opt for light watering to prevent waterlogged conditions and monitor the moisture levels closely. Consider providing well-balanced nutrients to support root regeneration and overall plant health.

Monitor and observe:

Keep a watchful eye on your plants as they bounce back from root rot. Monitor their progress and look out for any signs of reoccurrence. Remember to stick to your preventive measures to ensure long-term success.

This is a suggested treatment for root rot. But remember that your grow space is unique, so it may need to be adjusted to suit your specific situation. It’s also vital to repeat treatment methods regularly to have the best success at beating root rot. 

Closeup of pale root system growing through the bottom of a pot

How can Grow Sensor help you?

The Grow Sensor is a valuable tool, allowing you to effortlessly monitor your grow spaces. It enable you to access valuable insights on your growing environment and soil data at any given time. This information proves instrumental in enhancing the overall quality, quantity, and consistency of the cultivated end product.

With the Grow Sensor, you can effectively identify and manage microclimates, resolve issues, and minimise nutrient waste and pest problems. The provided insights are easily accessible through intuitive desktop and mobile apps compatible with Apple and Android devices. The insights empower decision-making, resulting in cost savings, improved return on investment, and enhanced profitability. 

The hardware itself is characterised by its innovative design, reliability, and precision wireless sensor equipment. This ensures quick installation, robust connectivity, and unparalleled accuracy.


Congratulations, you’ve made it through our ultimate guide on how to fix root rot in your cannabis plants! Armed with knowledge and preventative measures, you’re now equipped to tackle this common issue head-on. 

Remember, maintaining proper drainage, watering with care, ensuring adequate airflow, and practising good sanitation are your keys to preventing root rot. And if it does happen, don’t panic! With timely treatment and a little help from beneficial microbes, your plants can make a strong recovery. So, keep nurturing your green beauties and happy growing!

Author avatar
Lucy Starley
Co founder at Grow Sensor - the smart grow room monitor. Lover of art, animals, sewing, walking and mushroom hunting. Inbound marketing expert and expert tea drinker. Lucy is currently open for Guest posts.

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