Please help id problem with mint!

Good pics. Nope , would say it not fungal. Pics don't look like even tryign to go fungal , but they do look like.

In the one pic you cna clearly see the concentric circles and lighter tissue area around the circle and with all the varigation going on, looks like it might be viral to me especially if you have had whitefly on the plants.

There are several viral diseases mint get. Not sure if your plants are big enough and since you have treated them to try and see if it is maybe viral.

If you can, take an infected stem and cut it off and put it in a clear glass filled with some water just enough to cover the stemup to the bottom of of the first leaves. Hold it there for about five minutes if you can. Look close while you are holding it and see if you see any sort of white stuff coming out fromthe stem that looks a touch cloudy. Fluid from the stem may even come out and kinda just sit there in a little group, or turn the whole water cloudy.

Even if you have viral disease, wont hurt ya to eat the plant. some mints that have varigation have a special virus gene in them it could be the mint virus x . Could be that your varigate done, the whiteflies have feed on th eplant and then feed on the other plants and passed the virus which would account for yellowing and varigation in the other plants. The black spots are where the insects have been feeding and the leaf has tried to seal off that section.

If it is the virus, nothing you do can do for it, cuz it will travel to all parts of the plant including the new leaves. You'll just have a bunch of varigated leaves to eat and a colorful dish. Like I say, won't hurt ya at all.

Would still do like ecrane suggested and cut back on the watering and get your whiteflies under control. Would treat the leaves and the soil for sure.

green76thumb - Do you have an Extension Office near you? Or can you send in samples to the plant pathology lab at your land grant college?
We disagree here. These photos looked like fungal leaf spots to me. Starlight thinks they're viral, but that would show up as distortion in the new leaves, not as dark spots. It could include yellow blotches but you say that is variegation. I also see some very small white things in your third photo. What is that? The new leaves that are smaller could be from lack of sunlight and/or nutrients. I don't know what is required in the way of light from bulbs, but I just have to wonder if the mint is getting enough. Impatiens can take far less light than mint.

Have you had a chance to check out the roots on any of your plants? Healthy roots should not be black or mushy. The overwatering may have affected the roots (root rot), and that would affect the entire plant. And a weak plant is prone to fungal diseases ...

star:
I haven't had whiteflies. Pretty sure what I have is thrips.

Will try what you mentioned.

I agree, the variegation is pretty, but I don't think the spotted, decaying, leaves look very appetizing to eat, and the whole plant is declining with some stems just dying.

(Don't know if you all noticed, but the stems also have affected areas. Maybe girdling is causing some of the stems to wilt and die.)

I trade and sell plants and these aren't fit for that, not to mention, this could spread to other plants. It's easy enough just to throw out the infected plants, but by the time the damage is to that point, the pests may have moved to other plants, so I have to get to the bottom of this.

This mint is naturally supposed to be variegated, so basically I'm talking about the timing of the variegation starting to show up. I just think, since they weren't showing variegation when I got them, but are now, that maybe this triggered it to manifest--either by a virus (other than one that may cause the variegation) or from stress.

I will continue to treat the leaves and soil weekly. I plan to alternate between Neem, Soap & Sulfur and Permethrin sprays.

Maybe I can take them to the University-will have to find out about that.

I'm not sure we can rule out thrips because 'thrips cause your leaves to curl and look distorted' (ecrane3) or virus because 'that would show up as distortion in the new leaves, not as dark spots'. From what I've learned, both thrips and different viruses can manifest in a number of ways.

Here is just one thing I've seen:
"Generic symptoms of INSV include brown or black spots on the leaves and yellow, black or necrotic ringspots. Stunting, wilting, stem cankers and tip dieback can also occur. Sometimes, a mosaic, line or oak leaf pattern can occur on leaves, stems or flowers.

After an infected thrips feeds on a plant, symptoms may appear in as little as two days up to several months. For example, cyclamen does not show any symptoms until two months after an infected thrips feeds on it. Many weeds are resevoirs of INSV and do not show any symptoms at all. Color photographs of tospoviruses can be seen at the University of Maryland tospovirus web site at: http://www.agnr.umd.edu/tospo/

Fungal and bacterial diseases or spray injury are often confused with INSV. For example, spotting on impatiens can be due to a fungal leaf spot (Myrothecium) or a bacterial leaf spot (Pseudomonas). " from the webpage: http://www.hort.uconn.edu/ipm/greenhs/htms/tospov.htm

I don't know. I've looked at so many pictures, I'm about ready to just give up.

The white spots in the third picture? Most are just water condensation in the baggie. But, I think the one at the top is a dead adult thrips.

I'm pretty sure the plants are getting enough light. Hopefully enough nutrients. I am not sure if the light intensity or the cool temps might have something to do with the variegation showing up.

I suppose I should inspect the roots of this ginger mint, and then take the whole plant (bagged) to the University. I wouldn't be surprised if it's the fungus gnats that are causing the stems to die. I don't think I'll ever be able to eradicate completely the ones in the basement, but I've made great progress (about 95% gone) in the house.

Without seeing the plant in person, it is hard to figure out exactly what is going on.

CeeJay doe smake a good point, especially, since you grow and sell, to take them to yoru extension office or to the pathology lab. depending on yoru state, the extension office will not charge you. The colleges fees usually run from 10 to 20 bucks.

You can just about bet that the fungus gnats are happily munching on your roots.

Just out of couriosity, when you got those plants in, if they came from an individual, did you wash all the dirt off and give the roots a bath before repotting?

hang some sticky tapes up by your plants to help catch them fungus gnats and also you cna put slices of raw potato aroudn the base of the plant. Eggs wilbe laid on the potao slices and then you cna just throw them away and cut back on the water to help kill them.

Somewhere over in think it either propagation or seed germination forums is a big thread with lots of advice for getting rid of fungus gnats.

if you cover the soil with a thin layer of sand or aquarium gravel, the gnats will leave. rinse it first.

Well, I turned one of the plants out of its pot and into a ziploc so I could examine the roots. It didn't seem like there were nearly as many as I expected, so I poured out the dirt and then checked out what was left. There WEREN'T as many roots as I expected, in fact not many of the fine roots at all. What WAS there looked great and there was no rot.

Then I cut one of the stems and suspended it in a glass of water as suggested. Nothing came out of the stem, not even after 10 minutes or so.

I do have yellow sticky tape all over the place and it has caught a good many gnats. I've also been crumbling mosquito dunks into a bucket of water and then adding some of that to the watering can each time I water. I didn't know the trick about sand or aquarium gravel, but will keep it in mind.

I got these mints, and a few other sickly ones, from an online nursery. I do thoroughly wash the foliage and roots of plants I receive now. I can thank that nursery for the lesson.

Well, after 5 days, not much fungus-just a tad bit at the tip of a leaf and where a couple of leaves join the stem, but not from any of the spots. I'm starting to wonder if these spots are just the way this mint shows it was preyed on by an insect. The upstairs thrips problem really mushroomed overnight. I'll still use the neem, but I was getting creeped out by how many there were, and I could see them--so I hit them with pyrethrin spray and feel much better now.