Makes me think scale, can you scrape them off with your thumbnail?

No I can’t. I even tried rubbing it off with alcohol.

It’s likely honeydew that’s left being by whatever infestation the plant has.

Doubt it is honeydew. That seldom presents as colored and is also easily scraped or rubbed off with alcohol.

IMO, that looks more like edema but I have no idea why it should be 'sticky'!

I am not particularly good id ing pest problems, could it be a fungal/viral problem or environmental damage?

The brown is never going to go away that is permanent damage, no matter how much you wipe. If you never discovered bugs, you have to assume it was a fungus. The best thing you can do it leave it alone. Make sure the plant has very good air circulation and it watered properly.

The wet stickiness is from the plant it self. If you punctured a hole in the plant it would bleed. This fungus that caused this hole left it open to bleed. If it were an insect it would be feeding on those juices.

I seriously doubt it is a fungal issue. They just do not present like that.....a series of randomly scattered dots. Nor do they "open up" plant tissue to allow sap or plant juices to bleed out. At best, they will cause a rot that will be soft or sometimes sticky but there is nothing showing in the photos that would lead to that conclusion.

There are any number of issues aside from pest or diseases that can cause marks on plant leaves, including the edema I mentioned previously as well as physical or environmental damage.

Bone up on your botany, folks!!

@gardengal48 (PNW Z8/9) we are all just trying to help. None of us has pro by our names.

I might not be right on the fungal issue, but the juice is coming from somewhere. The plant is full of juices. Some how those juices are coming out of the plant.

It may very well be that the stickiness is indeed honeydew from an earlier insect issue. Plants do not ooze sap or juices just for the heck of it and in most cases, sap is not all that sticky anyway.

" None of us has pro by our names. "

Not sure what that has to do with the price of beans. There are a great many folks on these forums that are pros by virtue of the fact that they make their living doing this stuff and were around here and participating and providing horticultural advice long before Houzz and it's "pro" designations were involved. That does not make them any less experienced or knowledgeable than those that do attach that unnecessary label to their screen persona.

https://ask.extension.org/questions/490768

I have no idea about issues with philodendrons but when you think of something like Apple rust, it does look a little similar. If you eliminate insects, which or may not be the case, you look at disease or environment. Computer insisted on capitalizing Apple. Also, you do get sap leaking from both pest damage and cankers on stems. I can’t remember the terminology of it, but some plants also shed excess moisture through leaf tips.

https://pnwhandbooks.org/plantdisease/host-disease/cherry-prunus-spp-bacterial-canker

LOL!! Bacterial canker on Prunus and apple rust have nothing in common with any afflictions that will affect a philodendron. Or pretty much any other houseplant.

For whatever reason you want to come out as the superior person, on one hand you say bacterial and fungal issues never cause plant liquids to leak or seep, and when I provide an example you reply as above. I am just trying to help the op. Did you read the reply to the philodendron question I posted before that?

Pathogens that can cause an oozing of sap are relegated to woody plant parts, not succulent foliage. Bacterial canker causes stem and trunk lesions but will not show up as spots on the foliage. And apple rust does not produce any sap leakage. Also, neither disease is going to be present with any houseplant.

What is helpful is offering advice or suggestion that actually apply to the condition at hand rather than tossing out links to random websites that only confuse the discussion.

If it makes things easier I will copy the text from the link above.

Why does my Congo rojo have Yellow spots?

Asked October 17, 2018, 11:41 PM EDTSave

I received a transplant of a Congo rojo philodrendren plant. It recently has gotten yellow spots on the foliage. I'm not sure if this is normal or an abnormal. Any info helps, thank you!

Kent County Michigan

1 Response

Hello!

I'm sorry it has taken such a long time for a response. This one has me a bit puzzled--not much bothers philodendrons, as long as they receive the amount of water and sunlight that they need.

The yellow spots on the foliage are not normal for this plant. From the photos, they look like small, dry, sunken areas of necrotic (dead) tissue. Thrips cause damage like this, but I saw no evidence of these insects in the photos (the critters themselves, or their excrement). The pattern of damage left behind by thrips is also more concentrated, as they feed while moving across a leaf.

Might anything--household cleaners or polishes, for example--have gotten sprayed on the leaf? This spotting could be a chemical burn, in which case you would simply leave it alone. Unless subject to additional exposure, these burns would not spread. Once additional leaves form, you could remove this one, if you find it unsightly.

The other possibility is leaf spot, most likely caused by a fungal infection. Bacteria also cause leaf spot diseases, but the infected tissue is usually wet/slimy. If it's a fungal infection, it will likely spread across the leaf. If the plant had more leaves, I would suggest removing the infected one. Since it does not, and since the green areas of the leaf are still producing food for the plant, I would simply monitor its condition. Once new leaves develop, you can remove the infected one. You could apply a fungicide that is approved for use on indoor plants to new leaves as they develop.

Regards,

Becky Irey

Replied October 31, 2018, 1:25 PM EDT

Answered by

Becky Irey

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Here is another discussion on houzz

https://www.houzz.com/discussions/5296619/philodendron-leaf-spots

just so you know they're called nectaries. the plant secretes sweet liquid to attract ants to protect the plant.

This is textbook pest damage. My money is on spider mites, especially since you haven’t seen any pests. Those guys are teeny tiny and impossible to spot, even with a magnifying glass.

That's not spider mite damage.

It’s nectaries: read the link J Williams posted.

I’ve been having this issue with some of my philos for years. It is unsightly, but otherwise does not Impede growth.

rinse the plant in the shower once a week and the future spots will reduce a bit.

This is not a pest or fungal issue, it is natural for the plant and all plants to secrete moisture and sometimes a sap-like substance, just like we sweat. The sticky substance on this P. gloriosum is natural and not harmful. In the wild, the sticky substance attracts ants who eat it and any pests they find on the leaves. My gloriosum has the same thing and it has no pests or issues. Do not add too many chemicals or especially alcohol, as this will dry the leaves out (alco=hol in diluted amounts are good at drying out scale, mites, and aphids). If the plant is sufficiently hydrated, it will secrete more sticky spheres on the backs of the leaves.

EXTRAFLORAL NECTARIES. If your plants are healthy, you cant find any pests, and these appear on the stems and leaves, especialy on philodendrons (though many other types as well), it's a natural, healthy thing. In nature, these plants secrete this sweet sticky sap-like clear substance to attract ants, which protect them from insects that are damaging.