Please help id problem with mint!

I've posted pics here:
http://davesgarden.com/tools/blog/index.php?tabid=10677
(I don't know why the entries keep displaying in random order).

This message was edited Nov 16, 2008 4:50 AM

I got "access denied" on your link....

Shoot! Can you tell me if there is a good way to post a number of pictures somewhere on DG. I thought the journal might be a way, didn't realize I was the only one who could access it. Or, I could email you the pics. if you send me your email address. Thanks for your help!

Can you please try clicking on 'green76thumb' and see if you can look at my Garden Diary. (That's where it's posted-not 'Journal', like I had thought. ) I guess 'blog' is another word for 'Garden Diary' . . . ?

green, can you just try posting a picture or two here on your thread? then we can what the problem is (hopefully, lol).

Good idea-although I have 4, I'll post them one at a time
1. These spots have suddenly appeared on both of my ginger mints (separated from one pot, and grown in separate locations for a couple of months) which I bought 3 months ago.

They've been growing like crazy,so I'm thinking either the soil has some kind of disease in it, or the plants were never healthy to start with.

It seems to also be on the impatiens growing next to it

and my pear mint (from same nursery) growing by it seems to have it too.

i'm not seeing spots. maybe the last mint looks a tad overwatered but i don't see anything else.

I had regularly picked off bad leaves, but when I noticed there seemed to be a number of them, I took pics, then cut all the stems to the soil line. If you enlarge the pics, you should be able to see some spots on some of the leaves and stems. The ones that first caught my attention were small, perfectly round, black spots on the top of some of the leaves. The dark discoloration on the impatiens leaves is similar (to me) to what you can see in the first pics of the ginger mint.

The only thing I can see is normal - as the weather cools down, many plants start showing the effects in their leaves. That is what I see. FWIW, mine look worse.

Don't know that it matters, but mine are grown indoors and have not been outdoors in their life with me.

Well, that should make a difference. I've never grown these as house plants, however. Have you looked UNDER the leaves? Houseplants are prone to spider mites, although I don't see any indication in your photos.

Oh yes, I've looked them over really carefully. I'm just wondering if maybe that's the way it looks when thrips munch on the leaves. I'm coming to the conclusion that every plant looks different when that happens.
I am practically phobic when it comes to mites. Had a horrible broad mite problem last winter. Hope I never see that indoors again-in fact, impossible as it may be, I don't want ANY bug problems indoors, and I want to grow organically. As you can imagine, bug patrol can keep me pretty busy!

Thrips cause your leaves to curl and look distorted, I don't see that here at all. I can't really tell what's on your mint since it's hard to see the spots, but the stuff on the impatiens reminds me most of sooty mold which typically forms where there's been honeydew left behind by aphids, scale, mealy bugs, etc. Might not be that, but it doesn't look particularly like insect damage or like a real fungal problem.

Im hoping it's not a virus-like INSV.

Doesn't look like that to me.

Good. I'd still like to figure this out though. I don't want to be trading and selling things if they aren't healthy.

The thing to realize too is that plants aren't always going to look 100% perfect--there are going to be a few spots here and there, or a leaf with a hole chewed in it, etc but that doesn't always mean there's a problem that you need to do anything about. From what you show in your pics of your mint, I don't see anything I would be worried about (and I wouldn't worry too much about the impatiens either if the black spots don't seem to be spreading beyond the couple leaves they're on). But if you're getting increasing numbers of dark spots, I'd suspect a fungal problem of some sort so I'd keep an eye on your watering and make sure that you've got good air circulation around the plants.

Thank you. Yes, the air circulation is pretty good, but the spots have been spreading. I've been trimming them off as fast as I notice them, but there were a number of new ones that day (which I took the photos of). So, I was becoming concerned that it seemed to be worsening, but there weren't too many spots that day to take pics of since I'd been trimming them off.

Well, if the spots come back it would help if you could take a closer up shot of a leaf that's got a little more damage. I'd also check up on your watering to make sure you're not giving them too much, and also when you water make sure it's not splashing back up on the leaves, that's a very common way to get fungal spots on leaves

Lol! If only I were a better photographer! I'll see what I can do. But, here's to hoping I don't see them again!

Green thumb... I can see what your talkign about. Take a couple of the infected leaves. Put them in a plastic baggy and just let it lay on the counter for a few days. It looks like you have a type of fungal mold trying to grow.

If it is, those leaves you put in the baggy will start showing it in a few days. I would cut back on the watering and you piece sin the bag get the fuzzies, then I would treat your plants with a fungicide, not only the leaves but the soil.

If it is a fungal disease, just trimign the leaves off won't help cuz you wil be knocking spores on to other leaves and around on the soil.

That's a good idea. I had cut the stems all the way down and sprayed the stubs & soil with Neem, a few days later I sprayed them with soap/sulfur spray (or vice versa, don't remember for sure). Will see what happens with them now.
In the meantime, I have a few in the other room that I didn't cut down so far and did spray once with Neem. Whichever develops new spots first, I'll bag them.
I was keeping them very moist, probably overwatering them, so I will cut back and see if that helps too. Hopefully I don't have fungus on the roots. Guess if I do, I'll just start over with cuttings.

I haven't had particularly good luck with neem for fungus. I know it says something on the label about being antifungal, but in my experience it hasn't worked very well (the fungus I've used it on has been mold that grows on leaves in my greenhouse in the wintertime when we've had a rainy spell and the humidity has been high...it may work better on other types of fungus) I've had better luck with copper soap fungicides and sulfur-containing fungicides.

I agree with Ecrane. And if the mixing temp and application temps are not right, neem wont work at all.

that's a bummer : ( I've been counting on the neem to help get rid of thrips. I just bought the premixed stuff and I spray it on at room temperature.

It's worked fine for me with insects, just not with fungus. Check the label to make sure it lists thrips though, not everything kills everything and I don't know if it kills those or not.

if you put any green, growing leaves in a baggie, wouldn't they develope fungus? i'm not saying star is wrong, but it doesn't make sense to me.

look on the bright side. ya wont have white fly, scale or aphids. : )

track.. most fungi before I can identify them down to specific genus and species, we take the leaves and put them in a baggy to start them out. Some will stay in their asexual stage and some will go into their sexual stage. You may see spots on your leaves, but in a few days, those spots will turn into a bunch of growing mycellium. Then the mycellium is cultured out on a plate with an agar, sometimes with oatmeal flakes to feed them and keep them growing for observation then under the microscopes.

Nope not all will develop a fungus if they haven't been infected. Last week I was given some lilac leave s that had spots on them. In the baggy they went and nope they never did develop an fungus. Smuts and rusts on leave s generally won't either or if it a virsus .

Some you can put in a baggy and they will just rot, stink pretty bad and turn to mush but not develop any mycellium either.

Sometimes if your real lucky, you will get several different colors of mycellium growing and then the real fun begins to figure out who they all are.

thanks for clarifying for me! sounds like you are really into it! i love that statement, "sometimes if you're real lucky"! too funny!

Ok, that makes sense. I started thinking that if it was a bacterial problem, it would probably get worse in a baggie too. But-we are specifically looking for mycelia-not just for the spots to enlarge.
And I've been paying attention to how I usually water-I rarely get water on the leaves. But, I probably have been overwatering.
I am curious about one thing though-if mints are an aquatic plant, how can they be overwatered?

You can have fungal problems on your leaves even even if the plant's roots can handle the amount of moisture you're giving them. Wet soil creates a humid environment around the plant and that creates an ideal environment for fungus to grow, so if some fungal spores have found their way onto your leaves they can easily grow. That's why backing off a little on watering can often help problems like this. Some mints are aquatic but I don't think yours are, they can probably tolerate wet soil but most likely don't need to be soaking wet in order to be happy.

What I'm seeing still doesn't look fungal to me. I wish I could have seen it before the bad leaves were cut off. I see a few black areas, and in the impatiens some of the black follows a couple of veins. Not fungal looking... I also see yellowing in some of the leaves. Have the plants been fertilized? What kind of light are they getting?

Yes, the plants are fertilized and they vary from about 4-12 inches below the lights. I have, per 2' x 4' shelf 6 4' fluorescent bulbs. The newer ones are 6500k T8 (32 watt).

The ginger mint is a variegated variety-although it was all green when I got it, a couple of months ago. I divided it and put one in the basement and one in the den. Just recently I noticed how the variegation was showing up on the one in the basement-and its cuttings. Then I started noticing a lot of black spots on the leaves. I checked out the one upstairs (that I posted pics. of) and found lots of spots on it too. Around that time its leaves started to become variegated. Maybe it's just a coincidence, or maybe not.

The one in the basement started going downhill before the other. I found a number of stems shriveled and dead. Also, the newer foliage is smaller and sparser.

It is cooler in the basement, and things stay wetter longer, but I do have 2 fans circulating the air really well.

I bagged some of the leaves from that one. I'm almost certain what I have is thrips (and fungus gnats). What I don't know, is if the thrips have introduced or spread a disease. It looks like the neem killed a lot of thrips though, because I only saw a couple in the bag.

I'll post the pictures I took of the leaves in the bag-sorry they didn't turn out better.

and another

another

and this one-shows the back of the leaf, looks about the same as the front.