When your houseplant is wilted even though the soil is moist, when leaves are turning yellow and stems are soft, there is a good chance your plant has root rot. Sometimes it is possible to save an ailing plant, but you have to act quickly.
What is Root Rot?
Root rot is a catch-all term for plant diseases that attack a plant’s root system. It can be caused by several different fungi that may be present in the soil. Fungal diseases thrive in moist conditions, so these diseases develop rapidly in wet soils.
This condition also develops when soil is too wet for too long. An overly damp soil doesn’t allow oxygen to reach the roots. The roots start to suffocate and cannot transport water and nutrients to the rest of the plant.
Identifying Root Rot
Because this disease happens under the soil surface, it is easy to miss its development until it is too late.
Plants suffering from root rot will have yellowing leaves. Leaves and stems may be soft and mushy. There might be white mold on the soil’s surface or mold on the stems. Stems and leaves might have a darker, water-soaked look to them. You also might notice a foul odor.
Sometimes a plant will wilt suddenly, even though the soil is wet, which might make you think the plant doesn’t have enough water. In fact, the opposite is true!
Other times, the soil may be dry on the top, leading you to believe that the plant needs water. When in fact, deep down, the soil is saturated with water.
Wilt from rot root looks different from wilt that occurs when soil is too dry. When a plant wilts because it needs water, the leaves will have a gray or bluish cast to them, leaves are brittle and crispy, and of course, the soil is dry.
How Does Root Rot Occur?
The number one cause of this condition is poor-draining, overwatered soil.
A healthy soil consists of the mineral content of the soil, including the proper amounts of organic matter, and the spaces between these solid particles. A balance between water and air is needed in these spaces so that the roots can draw nutrients into the plant.
When the soil is too wet, there is no place for air. Instead, all the spaces are filled with water. Just like other living things, plants need air to survive. The plant suffocates in this overly wet environment.
Fungal diseases thrive in wet soil, too. When a plant is overwatered, the pathogens spread. Roots already weakened by a lack of oxygen can succumb to these diseases.
How to Fix Root Rot
You want to get your plant out of these conditions fast! The longer the plant sits in waterlogged soil, the worse the damage can become.
Some plants might be too damaged to survive, but if you see healthy roots that are firm and white among the rotted ones, there are a few steps you can take to revive your plant.
Supplies you will need:
- Clean, sharp clippers or scissors
- A pot with drainage holes, either a new one or a clean one
- Lightweight potting mix, either a commercial blend or you can make your own. Here’s a good all-purpose soilless mix recipe:
- 2 parts peat moss or coir (be sure it’s well moistened)
- 2 parts compost
- 1 part vermiculite
- 1 part perlite
- A 1:10 bleach-to-water solution for sanitizing your old container and your clippers, or bleach disinfectant wipes
- Newspaper to cover the work area, if desired
- Garden gloves
Here’s what to do:
- Remove the plant from the pot and dispose of all the old soil. Remove all the soil from the root ball.
- Look for healthy roots. Cut away any dead, rotten ones. Sanitize your clippers or scissors between cuts.
- Clean the pot thoroughly, and then sanitize it with the bleach solution.
- If the pot does not have drainage holes, don’t replant in it. Get a new pot with drainage holes. You can always use the other pot as a decorative cover pot.
- Replant in fresh potting mix.
- If you have trimmed away a lot of roots, you may need to trim some of the top growth as well. This gives the struggling root system less foliage to support while it rebuilds itself.
Keep your recovering plant out of direct sunlight for a few months. Monitor its watering needs carefully. Be sure it truly needs water before you get out the sprinkling can.
How to Prevent Root Rot
The best way to fix root rot is to prevent it in the first place. Here are five tips to help keep this disease away.
- Be sure the container you are using has drainage holes. Use a lightweight potting mix designed for houseplants (or make your own). Don’t use soil from the garden. It can be too heavy and may not drain well. It may also introduce pathogens and insects.
- Be sure the container is the right size. A container that is too big has a lot of soil in it, and a large volume of soil can stay wet for a long time. A plant with a small root system can drown in too much wet soil.
- Water properly for your plants’ needs. Some houseplants like to be kept constantly moist. Others like to dry down completely between waterings. When you bring a new plant home, do a little research into what it requires to thrive.
- Consider your plant’s location. It may need watering more often if it is in a sunny window. If the indoor temperatures are cool, or if humidity is high, a plant might need less watering.
- Every time you water, check to ensure the soil is really dry all the way through.
Sometimes a plant cannot be saved. You might be able to start over with leaf or stem cuttings. Or, you can buy a new plant.
