Extra Tips for Yellowing Leaf Neo?

[alecStewart1]

Hey gang,

I noticed this guy, Myeonggwanggae, had two leaves that were turning yellow kind of out of the blue.
It seems to be staying at those two leaves. At first I thought it was just naturally losing leaves, but something didn't feel right whenever I saw the leaf above the one at the base start to turn yellow-ish.

A few things I suspect as to why this is:

1. This guy was in a bark mix, and was moved to a moss mound
2. I forgot to apply fungicide to a root that cracked a little whenever I was making the mound.
3. The plant was getting a lot more direct sunlight than it should've been, the side where those leaves are were getting hit the most before I moved the rack.

I double checked the moss mound and it still had that pocket for air, so that probably wasn't the cause.

In the pictures you'll see I soaked it in a water and sulfur fungicide solution for a little bit (15 minutes), this morning I sprayed him with some BioAdvanced Houseplant 3-in-1 (it contains sulfur and some other compound that I can't remember the name of that starts with "Py") and I'm keeping it bare root to try and dry out out any potential fungus.

I have some Thiomyl Systemic Fungicide, a copper based fungicide, and Ceylon Cinnamon Leaf Oil from Ray coming in that I meant to get before now, but at least I got bought it now (thanks for shipping those out so quickly by the way, Ray).

Should I continue the treatments with sulfur and monitor the plant before I use anything more advanced?

[estación seca]

When did you repot it? I wouldn't repot a Neo in winter, only during warm weather when I see new root tips. If the old medium was so truly rotten I had to remove it, I would leave then plant bare-root over the winter, giving water only occasionally on warm days.

Damp moss provides a cooler root zone than does bark. Neos don't like being cool and wet. I wouldn't be able to keep them alive in damp moss in winter.

Don't use fungicide unless you know which fungus is attacking a plant, and that fungus is susceptible to the fungicide you picked. Various fungicides don't work on every fungus.

Rotting of plants is rarely due to fungus attacking a previously healthy plant. It's almost always caused by inadequate growing conditions. Fungicide is not the answer; it's improving growing conditions.

Different people have different opinions on growing. I think Neos in moss should be kept crisp dry all winter, only spraying the top roots on warm, sunny days, only one or two squirts from a spray bottle, not dampening the moss. If there are no warm, sunny days, I wouldn't water at all. They survive cool and bone dry for many months.

Over the years on OB I've seen numerous posts from people with rotting Neos. It's always been when they're too wet and cold.

[alecStewart1]

Originally Posted by estación seca

When did you repot it? I wouldn't repot a Neo in winter, only during warm weather when I see new root tips.

I repotted all of my Neos on March 31 of this year, when it was in the 70s.

Originally Posted by estación seca

If the old medium was so truly rotten I had to remove it, I would leave then plant bare-root over the winter, giving water only occasionally on warm days.

The old medium wasn't rotten nor was it rotting. The plant was running out of space in the pot it was in with bark, and I had a bunch of plastic Neo pots and the rankake I wanted to use.

Originally Posted by estación seca

Don't use fungicide unless you know which fungus is attacking a plant, and that fungus is susceptible to the fungicide you picked. Various fungicides don't work on every fungus.

Fair, but what fungus could it be if it is in fact fungus?

Originally Posted by estación seca

Rotting of plants is rarely due to fungus attacking a previously healthy plant. It's almost always caused by inadequate growing conditions. Fungicide is not the answer; it's improving growing conditions.

I checked last night and this morning and it seems like any issues are at those two leaves only. The stem is fine, the roots look fine, the plant has kept all of the keikis and none of the keikis look effected. Nothing is mushy or soft, it's just those two leaves. It could be nothing, but I don't want to take any chances.

To clarify culture, I've done everything in my power to prevent these plants from being over-watered. I'm not soaking the mounds, I'm just watering to where the roots turn green and the mounds get moist. The mounds roughly dry out fully after a day or every other day. It's getting warmer and humid here, tomorrow will be a high of 89 degrees Fahrenheit.

The worst I can say any of the Neos have been through is there was a surprise cold front early this month that also brought rain, but the mounds didn't stay wet from the rain for long. The coldest it got at nights was 41 degrees Fahrenheit, but that was a few days after the rain and all of the mounds were getting to dry. The only other thing is some of the Neos, this Myeonggwanggae included, got a little bit too much direct sun for a few days, this Myeonggwanggae especially so on the side where the two yellowing leaves are.

This Myeonggwanggae is the only plant with issues like this. Again, I will say, so far whatever it is seems to be contained to the leaves. The stem and the rest of the leaves are firm, the roots look fine (it's even starting to branch off new roots from existing ones), all the the keikis don't look effect and they're also growing out their leaves more. Maybe I caught it early, but, again, I'm not taking chances.

[estación seca]

I didn't see how far south you are. Those temperatures are probably not the issue.

Some fungi leave distinctive patterns on leaves, or do characteristic things to plants, but others don't. If a plant truly has a fungal infection but you can't tell which one from the typical attack characteristics, you need to look at it under a microscope. Sometimes that isn't even enough.

If you regularly have very high humidity in your area, like routinely over 60-70% without daily excursions below this, you might have fungal issues. If the relative humidity is routinely below this it would be uncommon for a fungus to attack. When you see damaged leaves always look for a cultural issue first; fungus tends to attack plants when they are already sick, or when conditions are too hot, too cold or too humid.

I suspect from your description it's sunburn. Some plants are more susceptible than others. If so the leaves should just fall off. The fact that it's making new roots suggests it should go on to do well.

[alecStewart1]

Originally Posted by estación seca

I suspect from your description it's sunburn. Some plants are more susceptible than others. If so the leaves should just fall off. The fact that it's making new roots suggests it should go on to do well.

One of the leaves fell off the morning when I was inspecting it again, forgot to mention that.

Again, so far none of the other leaves have anything similar. I'll probably wait until Friday before I see if I can wrap the guy in another moss mound. I'll make extra sure to give a bigger pocket in the mound for air, just in case.