Phal Disease?!

[sedazh]

Hi all,

I have about 22 pots of phal orchids and they were quite low maintanance until about a year ago. I think I brought in scale with a new purchase without realising and by the time I noticed, it spreaded to all😱 the infestation wasn’t too bad so I kept removing the bug with a wet wipe but the leaves started turn yellow slowly, and eventually they started dropping.

So I panicked, emptied all the pots, got rid of the media and moss, and sprayed the orchids with a common pesticide that is suitable for ornamental plants… I was so scared that was the first thing came to my mind🙄 I treated the pots as well, then put a little amount of moss/media mix at the bottom of the pots and placed the plants on top of it in their pots again. This was about two weeks ago.

Now they are back to their original place, north facing windowsil, but they are not doing that well. I spray the roots with a little water everyday to keep them moist and check the leaves, can’t see any bugs but some of them do have the sticky residue on the parts where the leaves are closer to the crown/roots. Does it mean the scale is still there? I am assuming it’ll take a while for them to get back to their good old selves however I can’t help but feel like they are slowly dying because of the pesticide😔

Anyway, I have couple of orchids that are really poorly and I don’t know what’s happening to them so I need your expert advice. One of my orchids dropped all its leaves a while ago but produced a new baby in the end and it was fine until a week ago. Today both new leaves droped when I touched it. The first two photos belong to her, can you help me identify the problem please?

The next three photos belong to another, they look like blisters but they are quite hard to touch and not oozing. It has this blisters for a while. It’s not dying but not exactly happy either, I am scared that it’ll die if I don’t treat it.

The last two photos was a third orchid’s last leaf😱 Is it root rot?! As I said my orchids were quite low maintanance, I only watered and feed them so I have never dealt with a disease before. Can you please help me identify and treat them?

Many thanks for reading my lenghty post!

[Dimples]

What pesticide did you use? If you only treated the plants once, it’s unlikely you killed all the scale unless you used a systemic synthetic product and those even recommend multiple treatments.

[sedazh]

I used the one in the photo, treated the plants twice and waited about 10-15days in between. But it’s not specifically for scale. You can see the sticky residue under the leaves, I am not sure if it’s due to scale but they are still there even after treatment😔

[Dimples]

I looked up the active ingredient in the Provanto, and it's a contact-killer insecticide. It will kill scale but has to make physical contact with the insects. I doubt it hurt the plants, but I don't have experience with that particular ingredient and I don't know if it should be applied to the roots. Some pesticides can be applied to the roots, others (like oils) should not be or should be used with caution on the roots. A soak and swish in lightly soapy water followed up with a thorough rinse will also help drown the scale.

Be vigilant, scale can hide down in the nooks and crannies of the leaves so they may come back. You can also kill them with a heavy spritz of 70% rubbing alcohol and remove them with a toothbrush after they die, I think it's called ethyl alcohol where you are?

The leaf loss looks like it may be due to rot down in the leaf base area where it attaches to the central stem. That's what I usually suspect when fully green or mostly-green leaves fall off abruptly, although the one leaf looks like it may have suffered sunburn? Were they outside or moved to a much higher light area recently? I can't tell what any of the other markings/damage is from the photos.

Keep the leaf attachment points dry and try not to let water sit in there. That will help prevent rot from occurring in the future. Good airflow around them will help too.

Sticky residue - there is something called "happy sap" that phals and other orchids will produce sometimes. It's a slightly sticky clear liquid and isn't cause for concern. Frustrating to possibly have happy sap and scale at the same time since you don't know what the cause is.

[Fuerte Rav]

Originally Posted by sedazh

I used the one in the photo, treated the plants twice and waited about 10-15days in between. But it’s not specifically for scale. You can see the sticky residue under the leaves, I am not sure if it’s due to scale but they are still there even after treatment😔

It's really annoying, the original product was PROVADO which was a systemic insecticide, and much better than Provanto. (The containers look almost identical) I haven't been able to buy Provado online for several years now but I'll be looking for it when I visit the UK later this year. If you can find some it's worth investing in - try to get the concentrate rather than the ready mix - it's much better value.

In the meantime I'm using BugClear Ultra which seems fine on my Phals and does the job against scale and mealybugs. After 3 treatments I change to using Neem Oil the next time I need bug treatment to avoid resistance building up.

Good luck!

[estación seca]

What are your growing conditions? Temperature, humidity, light?

[sedazh]

Originally Posted by Dimples

I looked up the active ingredient in the Provanto, and it's a contact-killer insecticide. It will kill scale but has to make physical contact with the insects. I doubt it hurt the plants, but I don't have experience with that particular ingredient and I don't know if it should be applied to the roots. Some pesticides can be applied to the roots, others (like oils) should not be or should be used with caution on the roots. A soak and swish in lightly soapy water followed up with a thorough rinse will also help drown the scale.

Be vigilant, scale can hide down in the nooks and crannies of the leaves so they may come back. You can also kill them with a heavy spritz of 70% rubbing alcohol and remove them with a toothbrush after they die, I think it's called ethyl alcohol where you are?

Thanks for all the info! Hopefully it’s just the stress from the scale and they’ll get better in time. I agree with you, it should not hurt the plant as the label suggests that it can be used on ornamental plants too but I have no experience with pesticides on orchids so who knows🤷🏻

I washed all the plants throughly in the garden with a hose and then sprayed all over with Provanto, including the nooks and crannies so🤞🏻 they are all dead!

I might have let some water sit in between the leaves as I am spraying them with water everyday. I’ll be more careful and make sure the water goes on the roots and nowhere else.

---------- Post added at 02:08 PM ---------- Previous post was at 02:01 PM ----------

Originally Posted by Fuerte Rav

It's really annoying, the original product was PROVADO which was a systemic insecticide, and much better than Provanto. (The containers look almost identical) I haven't been able to buy Provado online for several years now but I'll be looking for it when I visit the UK later this year. If you can find some it's worth investing in - try to get the concentrate rather than the ready mix - it's much better value.

In the meantime I'm using BugClear Ultra which seems fine on my Phals and does the job against scale and mealybugs. After 3 treatments I change to using Neem Oil the next time I need bug treatment to avoid resistance building up.

Good luck!

Good to know that, thanks, I’ll try to get my hands on a bottle of Provado! And we always have a bottle of Bug Clear for the roses, will keep that in mind too!

I was in The Netherlands last week and bought couple of new orchids, which I am keeping in a seperate place from the rest, and while there I also bought a pesticide called Promanal-R. I’ll treat all the plants with it again just to make sure. The only problem is the instructions are in Dutch😁

[sedazh]

This is the pesticide they told me to use for scale. It apparently works for mealybugs and one other disease but I don’t know what it is. There is a picture of them on the box though.

I have also discovere a spider web-like stuff on two of the new orchids that I bought from The Netherlands, on the leaves and some on the media as well. I am assuming it is spider mites?! It is really dissapointing to find bugs on an orchid that I bought from a big orchid breeder☹️

[Dimples]

That looks like an actual spider web.

[sedazh]

Originally Posted by estación seca

What are your growing conditions? Temperature, humidity, light?

They have always been on a north facing windowsill, it’s very bright but no direct sunlight. Temp fluctuates between 26-15 celsius, and the humidity is around 40%. They’ve been quite happy where they are and rewarded me with many flowers.

Until the infestation☹️ then about a month ago I took them out, to garden to treat/wash them easily, but left them there so I think that was a bit of a shock to their system. No media, no regular watering, yep I didn’t have any clue about what I was doing until I researched a bit. Now they are back to windowsill, with a small amount of media and moss at the bottom of their pot to keep them moist. The roots are out in the open but I spray water in their pot every morning.

My only concern is that their leaves look very pale, not usual bright green healthy looking orchid leaves. Do you think they need feeding or would they get better in time?

And I have this one orchid that always had leathery leaves even though I watered it regularly, even before the infestation. I tried soaking over night couple of times but no improvements. Its roots are in quite good condition too, so no clue why the leaves are like that🤷🏻