African Violet Crown Rot

African Violet Crown Rot

African violet crown rot, also called root rot, is a condition that develops in the plant’s roots when the soil or growing medium is constantly wet. It starts out with the roots dying because they are not getting any oxygen, but eventually opportunistic pathogens, such as the Pythium or Phytophthora fungus, will take advantage of the compromised roots. The rot will move upward to the crown of the root, becoming crown rot.

In this article, we will discuss the causes of African violet crown rot, as well as the measures to take to remedy the condition.

What is African violet crown rot?

Crown rot in African violets starts in the rootlets, which are the fine, hair-like structures that grow from the tertiary roots. When you uproot a plant from the soil and a root ball has formed, the rootlets will be intertwined with one another, holding onto the soil within the root ball.These rootlets are very thin and you may not even see them with your naked eye. Despite being minute, they are essential to keeping the plant hydrated because these rootlets are responsible for the absorption of water.

The water travels from the rootlets, up the tertiary roots to the secondary roots, then into the primary, or main root stem or crown stem.

When there is too much water in the soil or growing medium, the rootlets will clog with water and begin to rot. The rot in the rootlets will attract dormant fungal spores in the soil, and these pathogens will help the rot spread even faster up to the tertiary and secondary roots, until it reaches the crown stem where it will cause crown rot. The roots will turn brown or black and will start to feel mushy to the touch. Before long, the crown stem will also become brown and mushy. This generally means that the plant is severely compromised and may only have a slim chance at recovery.

What causes African violet crown rot?

The most basic cause of crown rot in African violets is overwatering. Several factors can contribute to the plant becoming overwatered, such as the soil or growing medium being too dense and compacted, making it retain moisture too well. Because the water becomes stagnant in the dense soil, the roots become clogged, leading to root and crown rot.

Another reason your plant may have root rot is if the temperature around the plant is hot during the day, but then drops to very low temperatures overnight when you water the plant. Watering the plant’s roots in the cold evening with cool water can lead to rot because the roots do not have the sun to help dry the soil fast enough.

Inversely, during hot summers, when you water the plant during the day, the soil dries out faster than normal and can also stress the plant and lead to root and crown rot.

A sudden change in the soil’s conditions can also cause the plant to become stressed and get root rot. If you have been letting the soil dry out too much for the plant’s first few months, and you then overcompensate by giving it too much water, followed by another period of drying out completely, these constant changes to the soil can cause root and crown rot because the root system becomes weakened.

One of the most common mistakes made by new African violet owners is planting the violet in soil that is not well-draining or using a pot that does not have sufficient drainage holes at the bottom. These factors, coupled with giving the plant too much water too frequently throughout the day, will damage the plant’s roots.

How do you know when your African violet has crown rot?

The most obvious signs of crown rot can be seen above the ground. You will see the leaves start to droop, and those closest to the base will turn brown and become mushy. The stem near the base will also feel mushy to the touch, and this essentially means that the crown stem has been compromised.

Normally, the leaves would feel firm to the touch, but in the case of crown rot, they are wilted and soft.

The first symptoms to appear are underneath the soil, so unfortunately you will only really come across these early symptoms incidentally. You might be repotting the plant and end up catching the rot in its early stages. If there are signs appearing in the leaves and stems, you should remove the plant from the pot to check the roots and see whether the soil is waterlogged.

Shake or wash off as much soil from the roots as you can, so that you can inspect the roots more easily.

Check all of the tertiary and secondary roots, as well as the crown root. If any of the roots are brown or black and if they feel mushy and soft, you have root or crown rot.

If the outside of the primary main root stem is mushy, then the inside of the crown is most probably rotten too.

If you want to be absolutely sure, you can slice off the stub. If the center of the stub is not green or red but is brown, it is rotten.

African violet crown rot treatment

Unfortunately, if the rot has reached the crown of the root, the plant is most likely too far gone to make it, despite any treatment measures.

Often, the best thing to do is uproot the plant and dispose of it properly, because it may take less effort to start over with a new plant.

If you want to save your African violet, however, you can try to do so.

First, make sure you quarantine the plant. Remove any dying foliage such as leaves and stems.

Remove the plant from the soil and shake and wash off as much soil as you can. Be gentle when handling the roots because they may be delicate due to their weakened state.

Using a sterilized, sharp pair of scissors, cut off the rotten roots until only healthy, white roots are left. Remove part of the crown root if you need to, but make sure there are enough healthy roots still left to give the plant a fighting chance at recovery.

Spray the healthy roots with a fungicide to protect them from reinfection and let the plant dry out on a paper towel on a wire rack or tray. The roots should be dry after a few hours. Repot the African violet in a pot with drainage holes, using fresh soil. The soil must be well-draining, airy, and porous.

Conclusion

African violet crown rot is caused by circumstances that lead to the plant becoming overwatered or the soil becoming waterlogged and soggy.

The rootlets become clogged and will start to rot, and eventually the compromised roots are attacked by opportunistic pathogens, such as fungi, that are dormant in the soil. The infection helps the rot spread faster to the tertiary and secondary roots, until even the crown of the root becomes rotten.

Most of the time, a rotten crown root means the plant is doomed, but you can try saving it by removing all the rotten parts and replanting the violet in well-draining soil, using a pot with drainage holes in the bottom.

Image: istockphoto.com / Olga Yakovleva