I use lime sulfur as a dormant spray against insects and fungal pathogens, and that stinks to high heaven. It works very well, but it should be applied at temps between 32-40*F when there is no active growth, especially new bud growth. It is also used for its antifungal properties as a wood preservative on deadwood of bonsai trees. It turns deadwood white unless ink is added to tone it down.

Live veins and deadwood on a juniper bonsai ^^^.

Al

I've been seeing a lot of information about flat mites in the hoya community. It's a big deal.

I did a ton of reading on how to identify them as well as combat them. Sulphur was identified in all of the articles I read. There are only a few poisons known to be effective.

I asked my friend who has owned a nursery for 35 years about the use of sulphur and he said it was safe to use on hoyas and unlike the poisons would be a much safer choice for me to administer. Now, I know it's gonna stink. So I'm going to have to apply outdoors.

So it's on my list of to-do also Bill. But I believe that you need to apply several times *maybe three times at one-week intervals) for it to be effective.

Let us know when you find out more.

I've had some very mysterious rather sudden illness in a few of my hoyas and I'm getting paranoid about flat mites!

I have one problem facing me. My huge carnosa is not mobile to go outside. I'm going to have to decide how to deal with her. She also has mealybug and I've never been able to get them under control for the same reason that I cannot move her outside easily to spray.

Sorry to add yet another comment, but I'm wondering if an upside-down dunk in the sulphur recipe may be easier for smaller plants than spraying. I feel like spraying is really difficult to get into all the undersides of leaves and stems.

Popmama, I too think dunking would be easier but I'm afraid all the substrate would fall out or rise up. I don't think there's any easy way to do this other than spray them and say someone else farted - of course not me!

As I said, I don't know if they are on my plants, but if they are it will kill them and maybe the increased growth is a side benefit. It's supposed to be warmer tomorrow, so I'll bite the bullet and do it. Maybe it will kill the mealies too. After a systemic, and a spray for almost 5 weeks prior to bringing them inside, today I went to check them out and heard "Hello....hello....hellooooo". Yep, a mealie. Boy those guys are tenacious!

Tapla - lime lime sulfur? Is that what it's called or was it a typo?

Just a minor case of redundancy from the department of redundancy department. Fixed it. Had stuff on the stove & couldn't tarry long enough to proof read.

Al

I am not a fan of any form of Sulfur - for the most part they are toxic to people and beneficial insects, and they burn many species of plants.

Why not use a proper miticide like Avid or Mavrik? Even the Bayer product "Bioadvanced Insect, Disease, and Mite" should be safer because it passed the stringent California approval process. I would still spray that one outside though.

edit: the optimal interval for miticide spraying is every 4th or 5th day, depending on the temperature.

Iochroma, my understanding of the reason not to use the miticide is because the active ingredient (at least in the Bayer one) is not effective against flat mites. I haven't researched Avid or Mivrik yet.

** i just looked and there is reference to Avid and Mivrik as effective.

fluvalinate* (Mavrik)

abamectin (Avid) tends to work better in combination with horticultural oil

Also, i did look at the Bioadvance and the ingredient there is Tau-Fluvalinate

I dont' know if Tau-Fluvalinate is the same as fluvalinate. Could be.

People in many countries cannot use the Bio-Advance because the other ingredient in it, Imidacloprid, is a banned chemical.

Bill, I would cover the top of the soil with plastic wrap. I like that self-sticking kind. Then dunk the plant upside-down into the sulphur bath only the foliage.

OK - the deed is done - for better or worse. It took me several hours to get everything (only the hoyas) outside on the deck. Then I mixed up two tablespoons of Sulphur with a gallon of rain water, did the shimmy shimmy shake and mixed it up real good. Then I sprayed every plant, top to bottom. I noticed a few things while doing this. One - it's extremely tiring! Having cancer, and being tired all the time doesn't make it easy. I also noticed how dry everything was. I swear these plants dry out faster inside than they ever did outside in the heat.

Fortunately, there was no odor. I was surprised at that because I thought it would smell like a fart party, but I couldn't detect any odor at all. I did see several mealies, which were promptly smooshed or sprayed. I don't think the Sulphur affects the mealies because of their waxy coating, but the fingernail certainly did! This surprised me because of all the spraying with neem I did prior to bring them inside, and by placing bonide granules on the soil surface, but I guess hoyas don't adsorb water as other plants do and the granules maybe take longer to work.

After letting the plants dry in the wind and sunshine, I moved them all back inside. This task completely exhaused me out. It was even harder than moving them outside, and to top it all off, now I have two more bottom saucers over than when I started! I have no idea how that works.

I will post an update on here as the plants recover. If they had mites, they don't now. If they has

d a fungus, they don't now. I look at it as a precaution if nothing else. Now it's just a wait and see, with daily checking for mealies, which an alcohol soaked q-tip will take care of them. The Sulphur does make the leaves look washed out, but I can live with that as the daily misting will eventually wash it all off. Again, everything is back inside and there is zero odor.

Now I'm going to conk out for a while. Zzzzzz....

I use Orchard Spray with sulfur and pyrethrin. The sulfur works well on mildew and I hope the pyrethrin keeps some insects in check. I mix 1 tbsp per gallon of water and it goes a long way.

hc mcdole, What's the smell like with that product?

How frequently are you applying?

The smell is not bad at all - you may smell it when you enter whatever room(s) you have your plants in, but it is mostly gone in a day or two. I use four rooms in the basement and notice a small scent of it when I go downstairs the day after spraying. It dissipates rapidly. When I compare it to Neem oil spray, I will take Orchard Spray every day over Neem.

Thank you! I also dislike neem oil.

Yep, neem stinks, or rather smells, and it lasts for quite a while too. Using the sulphur I didn't notice any smell at all. Even after the plants were moved inside, there wasn't any smell. I only mixed two table spoons to a gallon, and it seemed to be fine. I will update this post after a week or so as the plants continue to grow. What I'm hoping for, in addition to killing any mites they may have had, is for an increased growth potential. We shall see.

Thanks, Bill. I'm hoping for the same thing.

Well I bought one of those digital microsopes. They are not very easy to work with. You have to hold them very still if you are going to be able to see anything or you have to sit it on a flat/not moving surface. But in that case, you would really have to yank a leaf off a suspicious plant to put it on the table for viewing.

Be that as it may, I do see what amounts to some red dots and some other disgusting crawlie thing on the bottom of the leaves of what I consider my most suspicious hoya. One that was doing very well then suddenly started to decline. So that one and a few others will get the sulphur spray tomorrow. It's basically Winter here so my outdoor opportunities are not going to be as available. Tomorrow is supposed to be in the high 60s, so I'll take that opportunity to spray this one and a few others as well.

What I saw really made my skin crawl.

And I'm feeling very defeated already. Because here's the thing. I can spray some of my smaller hoyas, no problem. But I have some very large hoyas that will not be easy to spray. And I wonder if I get the small ones sprayed and then they just end up getting the mites back from one of the larger ones that I cannot.

I don't know. I feel very depressed about it today. I suppose that is the consequence of looking in a microscope. Facing the fact.

I now have two of the USB microscopes. They aren't great, but they are inexpensive and do a fair job. The first one has a gooseneck stand with a suction rubber base and a cheap board with grid lines. I bought an OTG connector so I could use it with my phone for portable work. That is okay for live view but taking a picture without the base is near impossible. The second one is similar but the stand is more rigid and is lowered and raised with a geared knob. Supposed to have more power than the first but I don't see it. I got it to see very tiny thrips on one of my begonias for the most part but it is good to see other things up close and personal.

Thrips using the first USB microscope.

To get the max magnification I took the small microscope off the cheap stand and pressed it into the leaf.

adult and nymph?

This is the best I could do with a DSLR and close up tubes coupled to a macro lens.

The new microscope is a tad better. The metal object is a pair of tweezers.

a very tiny tick that was embedded on my waist line this summer. Wasn't sure it was a tick because it was so tiny.

my garden dirty finger next to the tick.

Begonia seeds. The grids are 5 mm square. The seeds are almost dust like.

Viewing extra close shows the bad seeds (look tiny) compared to the viable seeds (plump - bigger)

Popmama, I too have a carnosa that is in a hanging pot which has leaves all over. I understand your problem. What I did was push the spray nozzle into random places among the leaves and spray the snot out of it. I figured like artillary, it'll kill a bunch outright, and the others will be so scared they won't show their heads for months! Just do the best you can and don't obsess over it. It'll be fine.

HC - thanks for the photos. I couldn't believe how small that thrip was. It's almost better not have the scope and not knowing! BTW - that tick, because of its size, could in all probably be a deer tick. They are tiny suckers. Dog ticks are typically larger. If you got it right away the chances of Lyme disease are practically nill since it takes them several hours before they can transfer the parasites. Best of luck to you, and thanks again for the photos.

Bill, I love you! "I figured like artillary, it'll kill a bunch outright, and the others will be so scared they won't show their heads for months! " That cracked me up and made me feel much better. It was just the virtual hug I needed.

Today, I mixed up a gallon of sulfur. Took eight small hoyas outside in a semi-shady spot (it's > 60 today with a breeze) and sprayed them good. I wore gloves, sprayed and sort of rubbed the sulfur wash onto the undersides of the leaves for good measure.

Ya know what? It wasn't awful. The smell is there but it doesn't make me gag as bad as neem did when I tried it. They are still outside getting some fresh air before they come inside with their sulfury scent.

I'm trying to decide which others to take outside now.

Now...remind me when we need to repeat.

Thanks for the pics, hc mcdole. I like that goosneck. Mine came with more of a clip-on base. It's really difficult to keep steady when hand held. I don't know how other people are doing it unless it's the fact that I bought a cheap one. I couldn't get any kind of decent still photo at all and everything still seemed rather blurry when i was just looking around. But I have a couple of hoyas that are showing the tell-tale signs and when I looked at one of them, I swore I saw tiny red dots. Not moving. According to sources on the 'net, these are likely eggs of the mites.

I also saw something more long and white moving across a leaf that was not a mealy bug. I have no idea what that was but I squished the back side of that leaf thoroughly! Eww.

I watched a video posted by BetsyBegonia. She's a well-known hoya enthusiast/Youtuber. It made my skin crawl!

Popmama, I'm just going to do the one spray for now. It's getting cold here and taking them outside now is not worth the risk. Since they won't get washed by rain or my garden hose, I figure if I leave it on any mites wandering around would stumble on it and it would just kill them (I hope). The smell isn't a problem, it's just that I don't want to spray inside my house. Besides, it's quite a chore and not something I would look forward to. I have very little energy as it is, due to the chemo, and taking on an indoor spraying is more than I could handle. I'll get them through this winter, and once spring rolls around, outside they'll go and then they can get sprayed well with sulpher. If I didn't see these stupid videos, I'd have happily skipped down the yellow brick walk and never known about flat mites, rotund mites, red mites. mighty mites etc. I just figured why not, it can't hurt and truthfully, I am looking for a nice growth spurt due to the spraying. Why they do that I have no idea, but most of the videos I've watched all resulted in increased growth. So, as long as none of them are named Audry, increased growth should be fine. Hey! Where'd me dog go?!

Yes unfortunately for me, I have seen the evidence of them. My hoya blashernaezii which had been doing beautifully, suddenly started losing leaves and I saw the dry patches (corking) all along the bottom of most of the remaining leaves. I had not changed anything: watering, light, fert nothing. I've always had a problem with mealybugs but this wasn't even infested with mealy. So I suspected something else was going on. When I saw all this hub-bub about flat mites, I was pretty sure this was poor blashernaezii's fate. And now I am seeing others with the same issue.

I hear you on the energy it takes. And I cannot imagine spraying this indoors. Our weather is wacky in Colorado so we could get nice days throughout winter. I will probably repeat the spray in 4-6 weeks.

Now I need to strategize what other hoyas to spray while I have a gallon of yellow sulfur juice.

Bill, as an aside, any compounding pharmacy / chemist will have flowers of sulfur/sulfur powder for sale (without a prescription). It's used by C&S growers to staunch / sanitize plant wounds / areas of rot.

Cactusmcharris - thanks for the info. I purchased a bottle of power from amazon for $10, and with only two tablespoons to a gallon, it'll go a long way. I didn't think pharmacies sold it any longer. When I ws a kid, I would go to the drug store, pick up a tin of sulpher and a tin of saltpeter (potassium nitrate) and mixt it up with some charcoal to make gun powder. I tried using it in rocket engines too, but all I succeeded in doing to them was to blow them up, so I stuck with purchasing commercial engines afterwards. Fortunately, some of them were reusable (if you could find them after landing!). Times have certainly changed, and I fear, not for the better either.

I was chatting with TikaLand last night and I promised that I would post some pictures of what I believe to be mite damage on my blashernaezii. This was a beautiful plant that was growing well. It quit growing, leaves fell off, and it developed these dry-ish looking patches on the bottom of the leaves. Sometimes I see these near the joint between leaf and petiole and I don't think too much about it. But these spread. This was the plant that started to really push my suspicion that I had the flat mites.

Sorry for the blur of pic #3.

Day before yesterday, I was able to spray about a dozen of my hoyas with the sulfur sludge. This one was first in line.

I had hoped to do 6 more yesterday. But the good weather left and it's now only 40 outside. So I'm on hold unless I can spray indoors somewhere.

The sulfur spray didn't smell nearly as bad as I had dreaded. But I'm still not sure what it would be like indoors.

That looks like mite damage for sure. Maybe spray in the shower? The odor isn't strong at all. Let us know how it works out for you.

Yeah I think on a small scale, I could probably spray some in the shower. I may get brave this weekend. I'll keep you posted.

Popmama, that looks like thrips damage to me.  

In my experience thrips generally don't like Hoyas but I have found them on Hoyas on occasion.

Elena, thank you. I don't think it's thrips. But when I get my magnifier that I ordered, I will probably know more.

I'm going to hope it isn't thrips because thrips, as I understand it, love aroids. I have many philodendrons, syngoniums, monsteras and pothos and none of them are being destroyed the way the hoyas are.

But if I see a thrip once I can get a closer look, I will report back.

Yes thrips love aroids :(.  They also love peperomias in my experience.  

Best of luck!! Keep us posted!

I'm here to give a couple of encouraging updates. It's been a little more than a month since I applied sulfur to about a dozen of my hoyas including the poor blashernaezii that I had seen the worst damage and behavior (no new growth, leaves falling off on a plant that once was a great grower).

I have reapplied the sulfur to that plant one time using a dusting method rather than spray. It has been very cold here now and that makes it difficult to spray if you want to do it outdoors.

Anyway!

The blashernaezii has new growth.

And here's my Minibelle. I imported this plant in April 2021 and it has never had any new growth whatsoever. It was alive, never lost any leaves. But it just never did anything until now. A new vine and two new leaves.

Of course this isn't any scientific study and this could be coincidental. But today, I'm considering these in the win column.

Popmama, I have seen similar results. A number of the vines have started to send out new leaves, and some of the other leaves have actually increased in size. I too have no idea why this was happening, because I didn't think any of the plants had mites, but thought I'd treat them just in case and maybe, as in the videos, I'd see new growth. For whatever reason, they too seem to be growing, even during winter! Don't know if they had mites and I killed them, or if the Sulphur gives them some type of boost with micro nutrients, but whatever the case, like you, I'll take the growth and put it in the win column myself.

I wish I had kept better records of when I applied sulfur to those hoyas. I only know from this post that it was about a month ago. So, I'm trying to keep better track now!

I found evidence of the horrible red monsters on my Rangsan today. Another hoya that basically stopped growing on top but has a substantial root system which I can see clearly because it's growing in leca. So today, 12/15, I applied sulfur to all my hoyas growing in leca. I used the paintbrush method rather than spray because I had to do it indoors. The odor wasn't terrible but the white splotches are more noticeable. Probably because my mixture has a higher concentrate of sulfur this time.

I've been kind of freaking out about how to dispose of the unused quantities that I have mixed up. Well lo and behold I just found an organic gardening article that says it can be applied as a nutrient supplement directly to plants. So I guess I can just distribute the mixed up slurry in my garden.

That article also states that it is good for plants because it is a trace mineral.

I'm going to be cautious dumping it still but at least I don't feel like it's impossible to dispose of.

More new growth.

Hanhaie Pink imported June 2021. Really has never done much of anything other than grow massive roots in semi-hydro.

Rangsan also imported June 2021. This plant got a peduncle really close to the center node about a year ago but nothing else. New growth and another short peduncle forming.

I'll take it! Hopefully the leaves don't all abort!

One more...Parasitica. Imported in April 2021. A whole new vine and I think I see growth activating on the little second cutting in the foreground too.

Greetings Holya lovers! I am researching flat mites on hoyas as I suspect my collection has them. I'm reading about the flat mite/false mite/red mite sulfur treatments every 21 days for 3 cycles to kill the entire life cycle. Did you do this? I see the one treatments gave growth results! did you follow up any more treatments or did just 1 treatment do the job? Thank you :) signed, worried hoya momma

Kelley, for me it was one and done. The growth and blooms have been spectacular! I don't know if my plants had mites, but sprayed anyway and am really happy I did. These are older plants which I've had for years, and although they grew and bloomed well, they were nothing like I'm seeing now. One other thing, I water them much more often than recommended. The medium is always damp and they seem to really love it.

Best of luck with yours.....

I'll be honest, I only did the one treatment and I did see good results. This was last Fall. Now that it's warm outside, I'm seriously considering another application. I'll probably get to that within the next week or so.

Epsom sss are lt would have done the same thing

@Tapla - why don’t you discuss the various forms of sulfur compounds for horticulture?