One issue you must look out for in houseplants is root rot. Fortunately, the plant will give signs of root rot, even though the roots are hidden. Common signs include curling or wrinkled leaves, leaf loss, a powdery substance on the soil, and growing mushrooms.
To fix root rot, you should stop watering the plant. Remove it from the pot, and loosen the soil to check the state of the roots. Cut off the mushy, discolored roots. Leave the firm, healthy roots. Apply hydrogen peroxide water solution on the roots. Repot the plant in a sterile soil mix.
How quickly you address root rot will determine whether your plant services or not. In this article, I’ll discuss the steps to fix root rot. I’ll also highlight the causes of root rot and how a seemingly harmless plant care routine encourages root rot in houseplants.
1. Identify Signs Of Root Rot In Plants
Overwatering is the primary cause of root rot in houseplants. When the roots sit in soggy soil for an extended period, they become mushy and rot. Meanwhile, the air pockets in the soil become compressed or are filled with water.
In the ground, plant roots grow as they search for soluble oxygen, soil nutrients, and water. However, potted plants cannot grow beyond the confines of the pot. Instead, they rely on well-draining soil to access oxygen through the air pockets.
When you overwater houseplants, the air pockets become compressed, restricting oxygen accessibility. The water also suffocates the roots. They cannot transport nutrients and water to the rest of the plant. Soon, the plants will start showing signs of deprivation.
Some signs to identify root rot are;
- Curling or wilting leaves.
- Yellowing leaves that eventually turn brown and die.
- Falling leaves.
- Powdery substances on the soil.
- Growing mushrooms.
- Unpleasant soil odor.
- No new leaf growth.
- Constant wet soil.
Unfortunately, you can easily mistake some of the signs for underwatering. I once made this mistake and made the situation worse.
My ZZ plant had classic signs of root rot, but the soil was dry, so I assumed it needed more water. I can be forgiven because I had recently acquired it and thought it was neglected at the store.
Weeks after establishing a regular watering routine, there was barely any change. The curled leaves remained the same, but they also started falling off. That’s when I decided to check its roots, and yes, they were rotting.
Root rot will sometimes present itself differently, depending on the plant and the extent of the rot. In my case, the odor, a common sign of anaerobic bacteria growing in wet soil, was initially missing.
However, over time, the signs became more obvious. Fortunately, I acted before I completely killed the plant with more water.
2. Cut Off Mushy Roots
Once you notice signs of root rot, the next step is to examine the plant roots. This is more or less the confirmatory test because you can easily see the state of the roots. Be keen when checking the roots to ensure you eliminate all the affected roots.
- Start by removing the plant from the pot. If the soil is dry, water it lightly. Gently use a blunt blade to loosen the soil around the pot.
- Remove the soil as you examine the roots. Run water through the roots to get rid of the soil holding the roots because you may miss some affected roots.
- Spot the soft, mushy, or discolored roots. Rotting roots change color to brown or black, while healthy roots are whitish and firm. You can pinch the roots lightly to see if they are bouncy. If the root hasn’t changed color but isn’t firm, it may be in the early stages of root rot.
- Use sterilized pruning shears to cut rotted or dead roots. You can also use a pair of scissors. Of importance is that you get to all the rotting roots. You’ll still have a root rot problem if you leave even one affected root.
Sometimes it is best to leave the roots to dry for a few hours before you treat or repot the plant. This helps reduce root wetness, especially when replanting in damp soil, as required.
3. Use A Hydrogen Peroxide Solution On The Rotting Roots
This step is optional, but hydrogen peroxide is a DIY root rot treatment worth exploring. However, you should avoid it if the plant is severely wilted. This treatment is primarily for the roots. A badly damaged plant may have severe root rot. Using hydrogen peroxide may worsen the situation.
In this case, you only need to cut the damaged roots and give the plant time to heal. Sometimes cutting off rotting roots in houseplants is not enough. The fungus and bacteria may still cause problems if the soil conditions allow their growth.
EPA and FDA have approved hydrogen peroxide as an antimicrobial agent. However, you should only use it when diluted. In higher concentrations, hydrogen peroxide can be harmful to your plants.
The 3% hydrogen peroxide solution (1:1 ratio of water to hydrogen peroxide) can go a long way to treat root rot in houseplants. When treating one houseplant, you can use one cup of water to dilute one tablespoon (15ml) of hydrogen peroxide.
Higher concentrations, such as 35% hydrogen peroxide, can still work. However, it may be wasteful if only one plant has root rot. You need more water to create a stable solution that will not harm the plant.
For example, 1 part hydrogen peroxide to six parts water reduces the hydrogen peroxide concentration to at least 6%.
Hydrogen peroxide in low concentrations poses no risks to the plant. In higher concentrations, hydrogen peroxide may damage plant roots.
When used correctly, hydrogen peroxide also has other benefits.
- It disinfects the fungi spores in the soil. Ideally, you should discard the current potting soil because it may have spores that will, over time, lead to fungal diseases and root rot. Fresh potting soil is usually sterilized and free of fungus. However, it is best to protect the roots with a hydrogen peroxide solution.
- It aids with soil aeration.
- It protects the houseplant from transplant shock.
- It boosts the root’s efficiency in absorbing and transporting nutrients and water to the rest of the plant.
- It stimulates root growth. Since you have to cut off the affected roots, hydrogen peroxide will stimulate new root growth and faster recovery. If the remaining roots cannot sustain the plant, you may be forced to cut back the houseplant. For example, you can get rid of weaker stems and dying leaves. Over time, a healthy root system will grow, and the plant will recover.
- You can also disinfect the pot with hydrogen peroxide, especially if you intend to use the same pot.
If the root rot was extensive, let the plant sit in the hydrogen peroxide solution for at least 30 minutes before repotting.
You can also drench the soil, spray the roots or use the hydrogen peroxide solution to water the houseplant over the next few weeks. However, you should be careful because hydrogen peroxide can sometimes weaken the plant, especially in high concentrations.
You can start by spraying the roots to see the plant’s response before drenching the soil with the solution or watering the plant over an extended period with hydrogen peroxide.
When using the hydrogen peroxide treatment, you should take several precautions.
- Wear protective clothing. Hydrogen peroxide poses little risk to plants, especially in low concentrations. However, it can cause skin and eye irritation if you don’t protect yourself when treating root rot in houseplants.
- Avoid using hydrogen peroxide in higher concentrations. 3% hydrogen peroxide is sufficient for houseplants. You may get away with hydrogen peroxide in higher concentrations when you treat root rot in outdoor plants, especially when drenching soil over a large area.
- Only use on the plant roots. Hydrogen peroxide is only beneficial when applied to the plant roots. If you spray it on the foliage, it can damage the leaves.
- Avoid using hydrogen peroxide in case of extensive plant damage. Avoid using hydrogen peroxide if the root rot is extensive and the plant is severely damaged. The hydrogen peroxide treatment may cause more damage to the plant in this state.
If you’d like to explore more options than using hydrogen peroxide to disinfect root rot soil, check out my other article: How To Disinfect Root Rot Soil: Easy Guide
4. Repot The Houseplant In Fresh Soil
Your houseplant is now ready to be repotted. If the plant is due for a larger pot, go up one size. Avoid transferring the plant into a pot that is too large because it will sit in wet soil, leading to root rot.
You can take several measures to ensure the rot doesn’t recur when repotting.
- Use the same pot (if it isn’t too big) as long as you first wash and disinfect it with hydrogen peroxide. You can transplant it to a slightly larger pot when you confirm that the root rot is under control and the plant is thriving.
- Ensure the pot has drainage holes. If reusing the pot, check the drainage holes. Sometimes they get clogged, especially if you don’t have drainage mesh.
- Get fresh soil mix. Since it is sterile, the potting mix doesn’t have fungi spores, which trigger fungi infections leading to root rot.
- Repot in a clear pot. This way, you can observe the roots through the pot and confirm that the root rot treatment worked. If you notice the roots have yellow spots, you still have a root rot problem. You’ll need to check the roots again. You may have left some rotting tissues spreading and affecting healthy root tissues.
- Use a ceramic pot, such as the unglazed terracotta pot. These pots are porous, so they let out a lot of moisture. Because of this, you’ll need to adjust the watering frequency. Additionally, roots that have had root rot will be drier in a ceramic pot than in a plastic pot.
- Put extra pumice in the soil mix. This will improve air circulation in the soil and boost the absorption of water, dissolved oxygen, and nutrients.
- Add houseplant food that contains worm castings. Worm castings will help with soil aeration. They will also help fight pests and diseases.
- If the plant is severely damaged, avoid adding fertilizer when repotting. You should instead wait a few weeks for the plant to recover before adding plant food.
- Don’t set the plant too deep into the soil. Ensure the base where the roots start to grow is above the soil.
- Gently tamp down the soil when planting. Since you have added pumice, the soil will still breathe. Very loose soil will have large air pockets, which are great for oxygen absorption. However, roots do not grow through oxygen. These large air packers will cause root dieback, resulting in another set of problems for the plant.
5. Water The Plant
You are probably hesitant about watering your plant, but your plant is safe now that you have treated root rot. Plus, the houseplant still needs water to recover. Remember, the root rot hindered water absorption, so the plant was thirsty.
Since you exposed the roots, you should water deeply to avoid transplant shock. Water the plants until you see water come down the drainage holes. After the first deep watering, avoid watering again until the soil surface is dry.
You can use your finger to check about an inch (2.54cm) of the soil. If it is dry, add more water. The plant care routine may change slightly after treating root rot. You may have to give the plant more time between waterings, but you should follow the plant’s lead.
If the soil dries out faster, water more frequently. If it takes longer to dry, you must wait a little more before watering. Factors such as humidity levels, weather conditions, and the plant’s location will determine how fast the soil dries out.
Besides watering, you can also mist the plant occasionally. This is especially important if the houseplant relies on fewer roots for nourishment or if the room has relatively low humidity.
When you mist the plant, it absorbs the water through the stomata on the leaves and stems. However, misting has its downsides. For example, the water droplets sit on the leaves too long, increasing the plant’s vulnerability to pests and diseases.
6. Find A Spot With Adequate Air Circulation
Poor air circulation is another cause of water retention in plants. Check the current spot for your houseplant, and see if it receives adequate air circulation. Some areas you should avoid placing your houseplant include;
- An area with too many indoor plants, especially those with large foliage.
- A spot too close to the walls.
- Crowded areas, including places with too many books and photo frames. If you must use these spots, ensure the plant is on higher ground where the soil has adequate air circulation.
- Damp spots.
Find an area with bright, indirect light and adequate air circulation for your houseplant.
If you have few options on where to place the plant, you can take the following measures to improve air circulation.
- Find a spot close to a window. Open the window to allow fresh air. You can also move the plants close to the window for a little while to prevent damp build-up, especially if they don’t get sufficient air circulation.
- Use a fan to circulate the air. Use a floor or oscillating fan to circulate air around the indoor plants.
- Rearrange the plants. Rearrange the plants that are close together so that there is sufficient space between the potted plants.
Can A Houseplant Recover From Root Rot?
When you first notice a change in your plants, the period between correct diagnosis and treatment matters. Root rot spreads into the healthy root tissues over time. How well the plant recovers will depend on the extent of the root rot.
A houseplant can recover from root rot if it has healthy roots and if you cut off all the rot. Pythium and fusarium fungi thrive in the soil and dying plant tissues, making plant recovery difficult. Fresh potting soil, the right pot size, and adequate air circulation will aid plant recovery.
How soon you spot root rot and your actions will determine whether the plant recovers. You cannot reverse severe root rot. A plant that loses most of its roots will struggle to survive. Instead of discarding it, you can propagate the cuttings to give it a new lease of life.
Signs A Plant Is Recovering
After treating root rot, houseplants don’t take long to bounce back. Some plants start showing signs of recovery within 1 – 2 weeks. However, if the damage to the roots is extensive, the recovery may take a few weeks because the plant will need more root growth to heal.
Here are some of the signs your plant is recovering from root rot.
- The plant will start having more green leaves. Yellow leaves are a sign of stress in plants. It is also a defense mechanism. When the plant is not nourished enough, some leaves turn yellow to give the plant a better chance of survival. As the plant recovers, the foliage will be greener and healthier.
- The leaves will stop falling off. Since you can’t keep digging out the houseplant to see if the root rot is gone, you should observe the leaves. When they stop falling off, it is a sign that the plant is in recovery.
- The plant may start leaning towards one side. This can be a sign that the upper part of the plant is recovering, but the root system is still too weak to support it. It can also mean the roots are not recovering, and the plant has a wobbly base that is likely rotting. You’ll need to look at other signs, such as the state of the leaves, to determine if the plant is in recovery.
- New leaf growth. When your plant gets new leaves, you can be confident that the root rot treatment worked. This is an obvious sign that the roots are healthy enough to nourish the entire plant.
Most plants recover after root rot if you remove all the damaged tissues. If you accidentally leave some rot, it will spread, and your plant may never recover. So, you must be very keen when cutting off the affected roots.
Your houseplant care, such as watering when the plant needs more water and improving air circulation, will also determine how soon you will start seeing the plant bounce back after root rot plant care.
How To Prevent Rotting Roots In Houseplants
Root rot can creep on anyone, including people touted to have a green thumb. The roots are hidden, and it takes some time before you notice signs of plant distress. Usually, when the plant “calls for help”, the damage to the roots is extensive.
You’ll need to act fast to save your houseplant. Fortunately, root rot is avoidable, and you can take steps to ensure your plant is not affected by it.
- Use the moisture meter to check if the plant needs more water. The finger test will help you decide if you should water the plant. However, it doesn’t consider the probability of wet soil at the bottom of the pot. A moisture meter has a long probe that goes several inches into the soil, giving a clearer picture of the moisture level. Regular readings will also guide you on the best watering schedule based on the changes in soil moisture levels.
- Ensure you follow lighting requirements for your plants. Low light conditions limit water evaporation. So, a plant that requires low light should not be watered as often as one exposed to bright light. Supplemental grow lights will aid plant growth, resulting in healthy root systems.
- Only use pots with drainage holes. Drainage holes give you a little leeway should you overwater your plants. At least, the excess water will drain out, and your plant will only utilize the water it needs. However, you must be cautious because drainage holes are only helpful if you follow the right watering routine.
- Get the right pot size. Planters that are too big for the plant retain wet soil for longer, leading to root rot. The ideal pot should be at least an inch (2.54cm) wider than the roots of slow-growing plants. Plants that grow quickly need a pot that is at least 4 inches (10.16cm) wider.
- Go for unglazed planters, preferably ceramic pots. These suck moisture out of the soil, limiting the risk of root rot.
- Use well-aerated soil substrate. If you have doubts about the soil mix, add pumice to improve aeration. Alternatively, you can choose specialty soil mixes for specific houseplants, such as succulent and cacti potting mixes.
- Water houseplants correctly. Overwatering can take the form of using little water too frequently or using too much water after the soil gets too dry. Both cases can lead to the plant roots sitting in wet soil, resulting in root rot. Only water the plant if the soil’s top 2 inches (5.08cm) is dry.
Here is a video offering tips on preventing root rot in houseplants.
Root rot is a challenge that anyone with houseplants encounters at some point. You should analyze the causes and point to the mistakes that may have led to this. However, the priority is getting to the roots and checking if some can be saved.
Once you fix the root rot, figure out the cause and how to keep it from happening again.
To prevent root rot, you need to observe the right plant care routine and understand the impact of the environment on the plant and its vulnerability to root rot.