KJSegall
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Joined: Tue Jul 03, 2018 8:46 pm

Mystery fungus (maybe) threatening entire container garden

leaves.jpg
Hello- this is my first post here. I'm hoping someone can help.

I have a patio garden that has grown very well, even with the Florida summer. However very recently I noticed the leaves on some of my plants growing brown edges very rapidly- overnight, actually. My garden is a mix of herbs and 'decorative' plants.

It started after a rain with some of my oregano, geranium, mint, and marjoram (the mint and marjoram are in the same holder; there is some thyme in the same holder as the oregano, but with the tiny leaves it was hard to tell if they were affected as well). Again it was after an evening shower, the next morning I was startled by how quickly the tips of the leaves had turned brown.

I had recently used Eliminator brand fire ant killer (I know, dumb with the herbs, I just won't cook with them for a while) to clear out a hefty ant infestation, and at first I thought maybe I had used too much in these particular pots and would just have to 'wait out' the damage. However today there was another late afternoon shower, and I found that several other plants had almost instantaneously developed brown edges- including some coleus cuttings that are sitting in water and were never exposed to the ant poison.

I'm worried that there must be some sort of fungus spreading through my 'garden'- its still somewhat sporatic, with what I would guess to be half of the plants affected. But as much as I search through Google, ask those wiser, etc., I cannot find ANYTHING that corresponds with these 'symptoms'.

The plants thus far affected are geranium, coleus, hypoestes (one, but not seemingly another, yet...), vinca, parsley, mint (2 seperate mint plants in 2 seperate containers), oregano, marjoram, sage, and dill. I live in the Tampa FL region. The plants show no additional signs of this being overwatering, and I can basically guarantee they are not underwatered. (Also, note that this damage seems to appear almost instantaneously, which in my experience poor watering damage is more gradual). Both 'spurts' of this appeared after a moderate rain- perhaps something getting spread around by the splashing?

Can anyone at all help me figure out what in the world is happening, and what I can do about it? I hate to lose my entire 'garden'...

imafan26
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Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

While fungal problems cannot be eliminated. Usually it takes a couple of days for most plants to show fungal disease after a rain. Fungal disease is not brought on by the rain itself which actually continuously washes the fungal spores off, but instead by the hot humid weather that follows rain. The fungal spores thrive in moist warm conditions. It usually takes three days for it to show up on most plants. That is why fungal prevention needs to be started as soon as the rain stops and repeated as long as the weather conditions persist.

Thrips may also be causing the symptoms you have. The geranium edges are dry and brown and there are brown spots on the leaves of the oregano/marjoram. The pattern is common with thrips that also like to go after stressed plants in hot and dry conditions. There are many kinds of thrips but most can be spotted with a good hand lens or microscope. There is usually frass on the undersides of the leaf. Thrips have many hosts and are are common this time of year.

KJSegall
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Joined: Tue Jul 03, 2018 8:46 pm

Thrips- I didn't think of that. I did have some on a second oregano plant in my garden, but they caused a totally different look (the pale white spots everywhere). Would they cause damage to show that quickly, and would rain "bring them out" like that?

KJSegall
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Posts: 4
Joined: Tue Jul 03, 2018 8:46 pm

Here are some more pictures:
marjoram.jpg
oregano.jpg
mint.jpg
dill.jpg
geranium.jpg

KJSegall
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Posts: 4
Joined: Tue Jul 03, 2018 8:46 pm

Update- I've checked, with a magnifying glass and all, and see no evidence of thrips.



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