Root Problems

Root problems can be a grower’s nightmare they can look like many other issues but often only have a few sources. Things that will tripper a root problem can be as simple as heat, cold, overwatering, wrong container, drainage or in hydroponics they can just lack oxygenation. 

Some strains can be finicky and have natural roots issues as well, this just means they need extra care.

Cannabis Plants with Root Problems Show Many Symptoms

  • Cannabis may appear overwatered or droopy
  • Curling or cupping of leaves
  • Wilting – either individual stems wilt or the whole plant may wilt
  • Leaf yellowing
  • Brown spots / Burnt spots
  • Other strange nutrient problems
  • Brown or slimy roots – this is often a sign of root rot
  • Smelly runoff water (smells rotting or musty)
  • Leaves may start dying and falling off rapidly
  • Plants drink much less water than usual

Overwatered marijuana seedling

Severely overwatered cannabis plant

The plant seen in the photo above is exhibiting classic root problems. Droopy and overall unhealthy look with newer growth being light colored and disfigured growth is a sign of an existing root problem. 

The plant below was not draining correctly, and the problems you see are from lack of oxygen to the roots. This is a common root issues one that can be fixed easily with creating however more drainage.


Over watered cannabis plant did not have any drainage - began drooping overnight after being watered


This cupping and folding of margins seen here also the outcome of poor drainage. If you are having similar issues wit your containers all you need to do is poke more holes in the container.

This particular type of cupping of the leaves are signs the plant has root problems.

The leaves that are deformed may not recover as the plant grows out of root problem.  As long as new growth looks healthy and good drainage exist you can be assured that these root problems are ending.

Sometimes leaves will tend to cup or curl down due to root problems, like the plant above, but sometimes the curl upwards too, like the poor plant below (this was caused by poor drainage and plant was overwatered, leading to a pretty severe case of root problems):

Folding leaves as seen here are also generally considered a result of root problems. The damage is uniform, not progressing like a deficiency should other than further folding.

Over-watered, no drainage leading to root problems - notice how dark the soil is and the green algae growing on top - these are more signs the plant has been overwatered for quite a while 

The plant seen below has been overwatered and now isn’t draining. The dark wet soil and visible algae is a sign of over watering. And the damage to older lower leaves that’s beginning to effect newer growth as well tells you that this issue has been happening for a while. Good idea here would be to clean up damaged leaves let plant dry down and then re water with a smaller amount and then let dry down again and repeat till new growth is green and healthy. This should give roots a chance to grow back.

Over-watered, no drainage leading to root problems - notice how dark the soil is and the green algae growing on top - these are more signs the plant has been overwatered for quite a while


The plant below is exhibiting many symptoms all at once. Lime green yellow leaves cupping upwards and red stems and leaf veins. The soil is dark and wet, assuming it had even a light feed it had adequate nutrients. But what you may not see is the grower here was unbale to attend his plant for an extended period of time so he over watered. This drowned the roots and eventually root problems created this mass deficiency.


The plants below developed root rot in a hydroponic setup. This is usually triggered when the roots can’t get enough oxygen, usually due to high temps or poor oxidation of the water. Notice the strange burnt appears on some of the bottom leaves. They turned almost white. The whole plant was drooping, especially towards the bottom. The roots turned brown (pictures below).

The plane below seen with lighter green color with lower leaves bleaching at the tips and edges curling to an almost white color. Over all healthy looks not good and is getting worse. This plant is in a hydroponic set up, where root problems exist when there is an imbalance of beneficial microbes or pathogens and or lack of oxygen. If you notice the roots are in poor shape, brown below, dingy green up top.

A cannabis plant affected by root rot - leaves are turning brown, discolored, burnt white tips and edges, curlingA cannabis plant affected by root rot - leaves have spots, burnt yellow tips and edges, curling

  The burnt discolored leaves of a cannabis plant with root rot

Root rot! No wonder the leaves were having so much trouble on top.



Treating a Root Problem

First thing when dealing with root issues is to find the source. 

  • High Temps

Create an environment where your core root zone is never above 74-78 degrees, air temps are what your plants will withstand. But roots need to be in a zone of 64-74 degrees for optimal transfer of water and oxygen and nutrients to the plant.

  • Overwatering

Drowned roots heal much slower than new healthy grow. Depending on what size your plant is watering less can be easy or hard.  Best way to correct overwatering is simply put water less frequently and allow proper dry downs to allow your media drain and establish a healthy biodiversity.

  • Pest

If you are inspecting you soil and notice any pest that eating your roots like: aphids, fungus gnats, Thrips larvae. Then treat the soil with a product designed with a drench. Or introduce a predatory species to either predate on the pest or out compete then for refuge.

  • Drainage

The most common issue leading up to and advancing a root problem is drainage. This can be for man reasons, and also easy to fix. A plant that need extra drainage can be repotted with perlite or another easy drainage amendment like hydrton to help eliminate stagnation. In chronically dense soils you can introduce enzymatic cleaners like Hydroguard or Cannazyme that aid in natural decomposition, as well as use Azos and Mycos from xtreme gardening to boost media a health.

  • Nutrient

If you root problems stem from too little nutrients and thus more then likely underwatering, water more, feed at a medium rate to encourage root expansion, and as the plant gets healthy up to a normal dose

Enough of all the pics with sad or unhappy roots – before you go, here’s a picture of healthy roots growing from a new clone!

  • Wrong Container

This can’t be stressed enough. Don’t put small plants in big containers or leave big plants in small containers unless you are fully aware of how to abate issues listed above, as they start much easier when a plant is in the wrong container.

These are a few inexpensive products that for the most part will work in any media or growing techniques that work as a preventative or reactive. Personally, I have had a lot of success with all these products at different times and each can be utilized from soil to hydro.

Hydroguard From Botanicare- An inoculant that cleans and removes decomposing matter and bad pathogens

Cannazyme from Canna- An enzymatic cleaner to decompose dead biomass in your media

Root Builder From Green Planet Nutrients – Another quality inoculant similar to Hydroguard but also helps boost root development. 

Azos/Mycos From Xtreme Gardening- These two products together aid in the nitrification cycle and inoculate you r soil with myco’s that will form a symbiotic relationship with your roots and aiding their defense and health.

Merrie Jayne shares her beautiful new roots - this clone is only 10 days old!

Scroll to Top