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How to Spot & Fix Root Rot

Hello plant lovers! Have you ever brought a plant home from the store and then noticed the soil smells bad and there are black spots on the lower leaves? Your plant could be a victim of root rot!

Never fear! In today’s blog I will tell you what causes root rot, how to spot it, and most importantly, how to fix it so your plant will thrive again.

What Causes Root Rot?

Root rot is a fungal or bacterial condition of the roots of a plant. If left untreated, in no time that bacteria or fungus will spread throughout a plant’s entire root system and cause it to rot even up to the stem.

The fungus or bacteria was already present in either the plant, cutting, or soil you are using. When it was introduced to an environment that was moist and without much oxygen it thrived. While it can happen to any plant inside your house or out, root rot tends to happen most commonly in containers and pots. It also happens more often in soil without small bugs like mites and springtails which play a huge role in regulating the breakdown of material and potentially harmful fungus.

The most common fungi that cause root rot are Rhizoctonia, Phytophthora, Fusarium and Pyhtium. But you don’t need no stinkin’ fungus to be in trouble. Just letting your soil get waterlogged will be enough to cause the bacteria already present in your root system to take over and start the rot.

How Do I Spot Root Rot?

If your plant is suffering from root rot there will be many signs before it’s too late to do something about it. Like any good plant doctor, the first step is to diagnose whether you are actually dealing with root rot or some other common issue. Inspect your plant and see if the symptoms you see point to root rot or not.

Other problems to rule out:

  • Burnt leaves from sun exposure or heat
  • Underwatering causing leaf loss 
  • Pest problems 
  • Fungal infections of the leaves 
  • Nutrient imbalance

What Root Rot Looks Like:

  • Leaves falling off that are far down the vine or stem 
  • Producing new leaves that are very small, or brown 
  • The stem near the base of the plant is mushy and wilted 
  • A bad smell in the soil and root system
  • Soil that stays wet weeks after watering
  • Black or brown spots on the bottom leaves
  • Melting, slimy, or mushy roots
How Do I Fix Root Rot?

The best way to stop root rot is to prevent it from happening in the first place:

  • Make sure that you are using a well-draining potting medium to ensure the soil is getting enough oxygen.
  • Remember that your plant needs time to intake the water around it, and will do best with at least a few days between watering (depending on the potting medium’s drying speed).
  • Another factor impacting your plant’s water intake is that your plant is getting enough sunlight.
  • Use beneficial bugs like springtails that eat decomposing material. This will vastly improve the overall health of your soil as well.
  • Use clear pots so that you can see the color of the roots which is a good indication of health.

If you are past prevention, and you have unpotted your plant to confirm root rot is the problem, these are the steps to follow to go about fixing it:

  1. Using clean scissors, cut off the affected roots or entire root system if re-rooting. Tip: A good way to tell which roots have been affected is to run a root through your fingers and give it a light tug. If the outside of the root begins to shed and leaves a thin strand, this root is rotten. The same goes for anything mushy or broken.
  2. Apply a spray fungicide to the root system that is 1-part diluted hydrogen peroxide to 3-parts water. A Systemic Fungicide may be needed in some cases of fungus that goes to the leaves to allow the plant to be treated internally. I would suggest putting the systemic liquid into water and putting the plant (after cutting roots) into that for a day or so to intake the medicine.
  3. Repot your plant into healthy soil, and water it just often enough so that it doesn't go bone dry. This will encourage any lingering organisms to die off as they are no longer in an environment in which they can thrive.

If all goes well, you will notice your plant intaking more water and pushing out the new growth you want! This is usually a month or two after repotting as it takes a while for a plant to recover. You may also want to take a cutting of your plant to save in case the root system declines again.