Crown Rot, Root Rot Among My Chimera African Violets

Crownrot

Above Crown rot, ( the work of the fungi Phytophthora)  I knew about it but never experienced it in my many years of growing African violets.   Well I was not only introduced to it first hand in December and January but it moved into my growing room and took up residence.   I have now lost 1/3 of my plants.  I believe now it has been banished from my plant room if not my house thanks to a number of practices I have changed and 10% bleach.   It was my fault.  I have always used a rather heavy potting mix as I try to minimize the time I spend watering plants.  And with this very early and very cold winter we are experiencing in Ohio (Temperature as of this writing is -5 degrees below zero or -20.5 degrees Celsius) I am seeing extremely  low indoor relative humidity levels.  The plants dry out then I over water.   I had not been inspecting the plants on a regular basis as I have been busy with other projects.  Root rot, crown rot is caused by the Phytophthora  fungus, which attacks the roots and, most notably, the crown of African Violets.  Usually the first sign and  symptom which I missed as I was not paying attention is the drooping of the leaves despite the fact the soil was moist, if not wet.  That was indicative of the fact that the roots have failed and are not absorbing the moisture.  At lease at this point the crowns are salvageable which I did a fair share of crown removal, bleaching  and rooting including a 10 yr old Granger Red and White stripe.  Most all the plants I removed the crowns and treated with 10% bleach and placed in fesh potting mixture or mixture that was baked at 380 degrees for 45 minutes.  They are all doing very well. 

Hear is a nice example of a very advanced case of crown rot.   

Rot2Rot3

Other Symptoms include but not limited to when the crown has a web like substance on and around it. Leaves become darkened and or wilt while green.  Growth is slowed or totally inhibited.

I did an extensive web search on treatments and the findings were rather dismal.  Nothing can really be done other then discard the plant and soil and pot.  On plants where the crown was still in tact I removed it making sure the cut was above the infected area.  I then placed the crown in a solution of 10% bleach (I prefer Clorox).  It was sealed in a container and essentially inverted for 10 minutes.  It was rinsed well and potted in soil that was baked at 380 degrees F for 45 minutes.  And the pots I used were also placed in 10% bleach for 30 minutes and rinsed well.  The crowns in their new soil (moist but not wet and much lighter)  were placed in plastic bags.  In 2 weeks most of the crowns has a nice little root system and were removed from the bags.

Prevention is always your best bet for successfully controlling Crown Rot I guess. But since I never had the issue I just assumed I was fine and it was not something I was concerned about.  So going forward I will  not overwater, I not let the soil dry out completely before watering.  Finally I started using a more light, porous potting soil.  I am also (for the first time) starting to consider some sort of self watering device.

I cannot end this post with the painful pictures of the carnage of a fungus.  The below image comes again courtesy of J. Miemietz, a grower of African violets  and an  exceptional photographer who resides in Germany.  This is her  Mauna Loa that was grown from a crown.  Good to know as bleak as things are or were on my plant stands in Ohio, things are green and in bloom in Germany.

Mauna Loa (Eyerdom)

3 Comments

  1. Posted February 24, 2014 at 4:25 am | Permalink

    Oh Don, it’s heartbreaking to see the pics of the crown and root rot. But we’ve all gone through it at some point or another. I experienced considerable damage this winter, when a scourge of powdery mildew raced through my cellar grow room, due to the natural course of winter weather. You’re a great grower though, and I know you’ll get this sorted soon. Looking forward to buying some crowns from you this Spring! 🙂

  2. Susan Terrell
    Posted August 11, 2014 at 8:26 am | Permalink

    Don, My name is Susan Terrell, Yesterday I was chatting with Jenner, buying leaves from her actually, I was telling her about my problem, Pythium. I took 3 of my plants to Oklahoma State University’s (Hereafter called OSU) County Extension Agent. He took the plant to OSU and they diagnosed the problem. They recommended I use a fungicide, And gave me a list of different fungicides. For the time being I am using Bayer Disease Control. They also recommended that I switch they kind of fungicide to give a complete control of the problem.
    I am intrigued by your use of bleach. I have heard of people dipping there plants in bleach and I have in fact used bleach when getting a new leaves.
    What I am doing right now is pulling the roots off of any suspect plants and making sure I have a healthy stem and spraying the plant down with a solution of the fungicide and putting the plant in a clean pot, and putting it in a zip lock. I am watering the plant in the new pot with water with the Bayer product in it.
    May I ask do you think I am approaching this correctly or if you had to do it all over again, would you use the bleach method again. I do realize that we have two different types of fungus. But I would like your opinion, since you have had similar problems.

    Thank You
    Susan

  3. admin
    Posted August 12, 2014 at 8:06 pm | Permalink

    Susan: I think your approach is a very good one and in retrospect perhaps I should have used a fungicide. It is much more efficient time wise and outcome wise. My issue was I waited too long. The bleach approach works very well but it is time consuming, one plant at a time. Also I believer the Bayer product is systemic in that it is absorbed by the plant as compared to the bleach which remains external. Going forward I have changed my approach. I will not be as reluctant to use fungicides when I see a multi plant outbreak of fungus. If I see the occasional one or two plants I will go into the bleach mode. Thank you for sharing.

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