Is this crown rot or something else? Are my plants doomed?

ZalperFebruary 24, 2013

Hello everyone - I'm hoping someone can help me. I just got started in this hobby 4 months ago and I'm encountering my very 1st disease which looks like it will wipe out my entire collection of baby plantlets.

A dark ring is appearing in the center of the baby plants affecting the parts of the leaves closest to the crown. I googled to see what it could be but it doesn't look like the pictures I see of crown rot. It looks very much like this photo posted on flickr:

These are plantlets that were started from leaves 4 months ago. They had spent their entire lives under a clear dome up until a week ago when I took the dome off. That's when the problem suddenly cropped up. (I did gradually prop the dome open before I took it off altogether).

The plants were now being exposed to cooler temperatures with lower humidity. I community wicked them and they were taking up a lot of water once the dome was off. My guess is once the dome was off the wicks started taking up too much water to compensate for the lower humidity. The mix is 1/3 perlite vermiculite & peat moss with an inch of perlite in the bottom of each pot.

About half the plantlets are affected and I am isolating them but I think all of the plants probably have the disease if that's what it is.

Does anyone know what this is and can these plants be saved? Thanks in advance.

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Hello Zalper,

I had similar issue too especially on wick watering or watering from tray. This is most likely due to fertilizer build up. When the plant was in enclosure, the humidity is high and not much further evaporation . But when u take it out from the enclosure, water start evaporation from top. Plants and soil draws the water upwards and evaporates, especially in winder where humidity is even lower than usual. The best way is the flush the pot with Luke warm water and run the plants under running water to rinse off the feet on the leaves... Hold off fert for about 1 month and observe.
I also see that the plants are too deep into the soil, maybe u can plant it for the crown to be a bit above the soil to reduce the issue of plant drawing up water and evaporating resulting in fert build up.
*my 2 cents worth.

Hope this helps.

    Bookmark   February 25, 2013 at 1:29AM
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irina_co(z5 CO)

I side with Ben - all his advice is excellent. I just want to add - young plants do not need as much water and fertilizer as mature ones. Consider using the thinner wick, may be 2 plys out of 4 - and either reducing the fertilizer to 1/8th of a teaspoon - or alternating your regular fertilizer with just water for your kindergarten tray.


    Bookmark   February 25, 2013 at 1:54PM
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Yup ... doesn't look like crown rot.

Your crowns look fairly healthy.

    Bookmark   February 25, 2013 at 5:35PM
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It didn't even occur to me about the fertilizer - but that makes perfect sense. Thanks for responding so quickly everyone.

I flushed them all tonight (even the ones that weren't showing the problem) and am hoping for the best.

I did take a closer look at how far down the crowns were and in some of them I took soil away so they were resting higher.

Thanks again for all the advice!

    Bookmark   February 25, 2013 at 8:20PM
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Zalper, do take some photos to share with us 1 month later to share the progress?


    Bookmark   February 26, 2013 at 10:54AM
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Hello All,

An update here. I've finally concluded it's the water and not the fertilizer because it was happening in baby plants that had never been fertilized. It's a reddish brown crust (iron?) forming on the innermost leaves of the plants.

IâÂÂm attaching a picture of the latest victim that was transplanted from a mother leaf a couple weeks ago. You can also see a brown crust forming on the perlite. Something tells me that is not a good sign.

One variety in particular is very sensitive to it (Caribbean Blue) but some varieties (Starry Night Blue, Buckeye Lazy Daze) are immune to the problem. Unfortunately, 75% of the varieties I'm growing now are showing this problem to some degree.

Our town water dept. claims the water is soft but lime scale deposits in the bottom of my coffee pot and at the drinking fountain at work say otherwise. I have lived in hard water areas in the West before and the local water where I live now in MA is not that hard, but apparently it has enough minerals it to cause problems. (Most of MA gets its water from the Quabbin reservoir which has very soft water but our town uses local ponds).

I have an aquarium test kit in storage that I will have to dig out to test the hardness and pH of the water. In the meantime I bought a few gallons of purified water (reverse osmosis) that I will be using for the time being.

If anyone else has some insight into this, IâÂÂd appreciate it, thanks!

    Bookmark   March 12, 2013 at 10:49PM
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perle_de_or(Zone 7)

I had some young plants with the same problem. I did flush with plain water and also used a Q-tip with warm water and rubbed gently and some of the rust color came off. I was very careful after that not to get the centers wet. My plants outgrew this condition. I bagged them after flushing and letting them drain really well, making sure that they were only just damp and left them alone for a while in the bags and they got much better. I also have very hard water. I made the mistake of using distilled water in the beginning which has no nutrients at all (dumb me). Some of my leaves began getting pale. After I learned that hard lesson I started using my tap water filtered in a Britta container and that has worked out well. Good Luck. I think your plants can recover.

    Bookmark   March 13, 2013 at 1:06AM
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irina_co(z5 CO)

Zalper - if you use store bought soil - not mix your own starting with peat - it comes preloaded with a fertilizer - which lasts for 2 months for adult plants - and it can be too much for the starters.

The good part - when the plants mature - they will grow out of this damage and it won't affect them afterwards.

If the municipal water has more than 200 ppm of minerals - it starts affecting the growth - your water district should have these numbers. You can start thinking about filtering your water if it has more or diluting it with AC condensate in summer - or rain water or distilled water from a store.

The yellow crust is not iron - it is the excessive minerals tinted with the humic acid - product of peat moss decomposition. It is a weak organic acid that eventually turns your peat based soil mix acid if you do not repot your plant for long time.

    Bookmark   March 13, 2013 at 2:51PM
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Thanks Perle & Irina -

Never thought about the peat staining the plants but that makes sense - especially since the perlite appears to be getting stained too.

The town water department claims the hardness is "under 125 ppm" but doesn't give an exact figure.

I'm using Hoffman peat, perlite & vermiculite which has no fertilizer. I did use a weak fertilizer on the first set of plantlets and that's what I thought was causing the problem. But it happened with the unfertilized ones too.

I did flush the first set of plantlets and then a few days later decided to repot them in fresh mix.

I'm hoping they outgrow the problem now that I'm using soft water and then I can go back to using filtered tap water when they mature.

Thanks again for the advice.

    Bookmark   March 13, 2013 at 7:31PM
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irina_co(z5 CO)

125 ppm is very good.

One our members mentioned a Miracle Grow perlite that costs more and comes fertilized.

When you repot - make sure that the wick is not too thick - if you are wicking - and the plantlet is sitting on a level or slightly above the rim. It helps increase the air access to the roots and excessive absorption of water.


    Bookmark   March 14, 2013 at 5:37PM
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Whenever I notice anything going wrong with leaves on my plants I hurry up and take the plant to the sink and run a thin stream of warm water on the leaf. Then I spray a little Safers Soap for plants on my fingers and gently rub the top and bottom of the leaf. This really does a good cleaning job but doesn't harm the leaf. Pat dry with a paper towel and return plant to its spot. Repeat after a few days, if necessary. This will eliminate bugs like mites, which plague African Violets.

    Bookmark   March 28, 2013 at 4:44PM
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irina_co(z5 CO)

Nope - it won't eliminate mites - you just need a couple eggs stuck in a leaf nook - and off they go again.

I am not sure you need to give plants a weekly bath - but with elimination of all the dust and grime I am sure your plants are growing quite happily.


    Bookmark   March 28, 2013 at 6:59PM
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