Cannabis Cultivation

Keeping Your Cannabis Roots Healthy

Keeping Cannabis Roots Healthy

Many cannabis growers believe that the most important part of their cannabis plants is the buds, or flowers. While they are very important for us, to get big, healthy high potency cannabis flowers it is also very important to take care of your plant roots. Without keeping the cannabis roots healthy, the plant will have deficiencies , grow very slowly, and serious cannabis root issues can even kill your plants growing above ground. 

Keeping your roots healthy, for new growers managing cannabis root health is often difficult as unlike the upper cannabis plant new cannabis growers are unable to see the root of the plant. 

What should Healthy Cannabis Roots Look Like?

Whether you are growing cannabis in soil, soilless, or hydroponics cannabis roots should always look white in color. These can become a bit brown in color in hydroponics and can still mean that the cannabis roots are healthy. This is because the color of some of the nutrients that growers use in their systems can change the color of the roots. 

Cannabis Roots Healthy
Healthy Cannabis Roots

Also cannabis roots should smell earthly, never have any kind of rotten or other smells no matter how they are grown. If the roots have any other smells it can be a sign that there are issues with your system.  If the roots look or smell rotten this is a serious issue in your system and it is time to fix the issues as quickly as possible. We will detail what to do about these things below. 

The key to keeping cannabis roots healthy is to check them regularly and especially during transplants. 

The Importance of keeping the Cannabis Root Zone Warm

To grow healthy and strong cannabis roots it is important to keep them at the correct temperatures. Many growers will keep their growing containers located on the floor of their grow rooms that may be much colder than the actual air in the growing space. If the root zone is continually cold it can send the plants into shock and severely stunt the plants overall growth. 

We recommend never letting your cannabis root zone get under 57F (14C) to avoid shocking your cannabis plants. If your growing space gets this cold during the lights off period it is wise to use a heating mat under your pots and warm your hydroponic cannabis nutrient solutions. 

Never use Cold Water on your Roots

Likewise growers should never use cold water over a warm root zone. There is only one reason that growers do this. Doing so at any other time will shock your plants and slow new growth considerably. Some growers like to do this the day before they harvest their buds as they believe that shocking the plants just before harvest will increase the potency of their buds. We however don’t recommend doing this at any other time in the plant’s growth cycle. Doing so will keep your cannabis roots healthy. The best temperature when watering cannabis should be at room temperature. However in hydroponics keeping the nutrients solution slightly cooler is preferred to prevent root rot discussed in more detail below.

What do your Cannabis Roots Need to Stay Healthy?


To keep your cannabis roots healthy they need a few things. First and maybe the most important of all is Oxygen. Without oxygen in the roots will not be able to move things like nutrients up to the green part of the plant. Using heavy, wet, non-drainable soils like clay, can suffocate your roots and kill your plants in a few days. For this reason it is a good idea to use light, fluffy soils that have very good drainage. There are things that you can add to your potting soils that will help with drainage such as perlite, vermiculite, and coco coir. These soil amendments will allow for the water to drain quickly from the cannabis growing containers

In hydroponics the oxygen is pumped into the system with pumps and air stones. If either of these was to fail, the plant roots would drown and the plant would die. 


Without the correct nutrients in the correct amount your cannabis would stand no chance and die. Your roots are the main drivers for the plant to use the nutrients that you are providing to keep cannabis roots healthy. The roots of our cannabis plants also need nutrients to grow and thrive under the soil or in hydroponics. 

Cannabis roots need healthy amounts of potassium and phosphorus in order to grow healthy and thriving roots. We recommend using organic nutrients that are high in both of these things in order promote healthy growth. Some organic nutrients that can be added to your growing mix include, fish meal, bat guano, greensand and kelp will all boast the availability of these nutrients for your roots. 

Water and Just as Importantly Dry Cycles

Without water the soil microbes would have no way to break down those organic nutrients in the soil, and just as importantly the plant would have no way to absorb these nutrients. In fact cannabis can not even use calcium provided to them with water to bring this nutrient into the plant. 

Growers must also be very careful when watering their roots, too much water will restrict oxygen getting to the roots of the plant, too little and the plant may dry up and die. Growers should implement a timely watering, drying, watering cycle that allows the roots and soil to dry out between each and every watering. Keeping your cannabis roots healthy means that you never overwater and have a wet growing medium. The only time the growing medium show is fully wet is directly after they have been watered. After that the plant’s roots should be allowed to dry out before adding more water. Not overwatering cannabis seeds or seedlings is also very important as overwatered cannabis seeds can quickly rot.

Healthy Cannabis Roots on Clone

Common Cannabis Root Issues

There are a few common issues that cannabis growers can run into while growing cannabis. We will detail these issues below. 

Root Rot

Root rot is a condition that occurs when the roots of a cannabis plant are submerged in water for too long, causing them to become waterlogged and unable to properly absorb oxygen. This can lead to the roots dying and the plant becoming stunted or dying. The most common cause of root rot is overwatering, but it can also be caused by poor drainage, high humidity, and a lack of air circulation around the roots. 

Root Rot

Symptoms of Root Rot in Cannabis 

Symptoms of root rot include yellowing leaves, wilting, and a musty odor. To prevent root rot, it is important to ensure proper drainage and to not over-water your plants. If root rot is suspected, it is important to address the issue quickly in order to save the plant.

How to Prevent Root Rot in Cannabis

Root rot is a common problem in cannabis plants and can be caused by a variety of factors, including overwatering, poor drainage, and high humidity. Here are some steps you can take to prevent root rot in cannabis:

  1. Use a well-draining growing medium: Make sure that your growing medium has good drainage to prevent water from sitting around the roots for too long.
  1. Monitor water levels: Be careful not to overwater your plants, and make sure that the soil is not waterlogged. Use a moisture meter to check the moisture levels in the soil.
  1. Provide proper ventilation: Good air circulation helps to keep humidity levels low, which can prevent the growth of mold and mildew.
  1. Keep the temperature cool: High temperatures can increase the risk of root rot, so make sure that the growing area is kept at a temperature between 70-80°F.
  1. Monitor for pests and disease: Keep an eye out for signs of pests or disease, and address any issues promptly.
  1. Prune roots if necessary: If the roots are overcrowded or have become matted, prune them to promote healthy growth.
  1. Use preventative measures: Some growers use fungicides or root inoculants to prevent rot before it happens.

It’s important to pay attention to your plants, and if you suspect a root rot issue, act quickly, as it can spread quickly and be hard to reverse. If the root rot has progressed too much, the plant might not recover, and the best course of action may be to discard the affected plant and start anew.

Does Cutting Cannabis roots hurt the plant?

Cutting cannabis roots to keep them healthy is much like cutting and trimming the top of the plant. While you never want to cut more than ¼ of the plant’s root ball, trimming the outside roots can help the plants grow more and have strong root ends. Most of the water and nutrients are taken up by the tips of the roots. So like pruning the tops of the cannabis plants, trimming roots will also create more end tip roots, these end tips are able to take in more water and nutrients to keep cannabis roots healthy.  

Bottoms of Healthy Cannabis Roots
Root Bound Cannabis

What is Root Bound?

Cannabis plants can get root bound when the plant has been in a growing container for too long. This happens when the roots circle the plant pot over and over. When this happens it can stop the plant from taking in valuable nutrients. When this happens it is time for the grower to transplant the plant into a larger container so the roots can once again start to spread out into the growing medium.

Cannabis Root Pests

There are two main pests that damage cannabis roots. 

Fungus Gnats

These small bugs are somewhat harmless to your plant in small amounts, however they can get out of control very quickly in your cannabis growing space. Also the adult winged insects can get stuck in your sticky cannabis buds. Who wants to smoke cannabis bugs right?

Fungus gnats are small, dark, winged insects that are common pests of potted plants. They are attracted to moist soil and can often be found flying around the base of the plant or on the surface of the soil. The larvae of these insects feed on fungi and other organic matter in the soil, which can damage or kill young plants. 

Adult fungus gnats do not cause damage to plants, but their presence can be a nuisance. To control fungus gnats, it is important to keep the soil in cannabis plants dry and to remove any dead leaves or other organic debris from the soil surface. Additionally, sticky traps can be used to trap adult gnats, and biological control methods such as nematodes can be used to control the larvae.

Root Aphids

Root aphids are small, soft-bodied insects that feed on the roots of cannabis plants. They are typically found in the soil around the base container of the plant, and can be a serious pest in greenhouse and indoor cannabis grow spaces. Root aphids can cause a variety of problems for plants, including stunted growth, wilting, and yellowing of leaves. Root Aphids can also transmit viral diseases between plants. Root aphids are difficult to control because they are hidden underground, but there are a few methods that can be used to manage them. 

These include using beneficial nematodes to control the aphids, using insecticidal soap to kill the aphids, and using a combination of cultural and chemical controls. Cultural controls include keeping the soil dry and maintaining good drainage, as well as keeping the area around the plant free of debris. Chemical controls include using insecticides that are specifically labeled for use on root aphids.

Final Thoughts for Keeping Cannabis Roots Healthy

When caring for cannabis roots, it is important to provide the right growing medium, proper water and nutrient levels, and suitable temperature and humidity conditions. The roots should be kept moist but not waterlogged, and the pH level of the water and nutrient solution should be kept between 6 and 7. 

Cannabis roots also need oxygen to thrive, so it is important to make sure that the growing medium is well-aerated. It is also important to monitor the plants for signs of pests or disease, and to address any issues that arise promptly. Additionally, pruning the roots can be beneficial in promoting healthy growth and preventing overcrowding.

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