Hi Lin,
The Peperomia leaf looks like normal callus - the kind of thing you get if the leaf is reacting to external damage - perhaps in the past that leaf was rubbing up against another leaf or something else - I'd suggest the same recipe - remove the affected leaves and chuck them out. As you say, the plant is not visibly suffering - it is just that we like all of our plants to look "perfect" and I doubt this plant, like your H. obovata, will miss a couple of leaves. The H. blashernaezii problem seems to be different - it affects more of the plant, and seems to damage leaf growth and plant vigour. I am really interested to see what results come back from the "plant experts" later this week.
That's a nice Peperomia by the way - do you know the species? I really like the succulent Peperomias, they are a much under appreciated Genus. Check out this cute Australian native one, I just love the hairs: http://australiansucculents.com/index.php?mact=Album,cntnt01,default,1&cntnt01albumid=75&cntnt01pictureid=482&cntnt01returnid=79&page=79
Ciao, KK.
Help! Stuff on back of Hoya leaf, good or bad?
I have a very hard time identifying plants from photo's but have always thought this Peperomia was P. obtusifolia: http://www.floridata.com/ref/P/pepe_obt.cfm and in PF: http://davesgarden.com/guides/pf/go/127999/
This was vaguely familiar but I have checked my Hoyas with no sign of it. When Lin mentioned the Peperomia, I remembered I had this with one of them in the past. I believe it is an oedema (edema) corky scab which caused by growing conditions and doesn't spread as such.
Oedema is physiological, not caused by an organism. It causes raised, scab-like swellings appear on the underside of leaves. These first appear as water-soaked blisters and may turn rusty-brown with age. This condition is often associated with inadequate light levels as well as overwatering, especially during periods of cloudy, cool weather. This problem can be minimized by careful attention to moisture levels in the potting mix, especially during cloudy weather. Also recommended to remove the damaged leaves and stated that under proper growing conditions, new growth will not be affected.
edited to add ~ this is most common in woodier plants, Hoyas, Peperomias, Citrus and other fruit trees as well as cacti and succulents.
This message was edited Jun 7, 2009 11:16 PM
This message was edited Jun 7, 2009 11:17 PM
Can I just say I have what looks like exactly the same condition on a few of my hoyas. I also first noticed it first on my H. blashernaezii, I think, and like Lourdes, have it on the entire plant, altho its a small plant, so dont want to cut them off. It dosent sem to be really harming the plants, and really seems to be on the undersides of the leaves, tho I think it has spread onto to top of a few, where it seems to more resemble corky circles, as opposed to the smoother all over covering underneath , but it is a bit unsightly. Mine are all grown outside but under shade cloth, so not sunburnt. ? Albeit, I think it was the first one to show it, but not 100% sure. Fungicides havent helped on mine either
Dominic
This message was edited Jun 8, 2009 3:58 AM
last pics didnt seem to post
try with text again for next
Just to add my .02 to the mix.
Since this discoloration is on the underside of some of the leaves, it is unlikely that it is sun scald. I could see sun scald on the tops of the leaves, but not on the underside (where the leaves don't ever see any direct sun).
Treelover: Yes, I think we've determined it isn't from sunburn.
Pod: Thanks so much for sharing that information! It's given me much insight, and is helping me to narrow it down a bit more! Corky scab sounds exactly how I would describe what I'm seeing on the backs of the leaves. In some places it looks corky and other places it's more like a flat smooth scab.
This is the location and conditions of my plants in question:
PEPEROMIA: has been on an enclosed porch, extremely hot and dry conditions, low light corner because shade is drawn to keep out hot sun. I never seem to remember to water the plants here on this porch very often (not often enough at times) so the Peperomia has been very dry.
HOYA: blashernaezii and obovata both on a covered deck, usually in bright light, no direct sun. BUT ... both of these were crammed in among other plants so were not getting much light at all!
All of my plants are planted in pretty much the same mix which is a combination of mostly orchid bark, a little potting soil and perlite. This mix is loose, airy and drains quickly.
My problem is definitely not an issue with over watering, but with the hoya there is still a water/moisture issue because of the weather we've been having lately. Both of the hoya's were in a dark corner of the deck and since it was very dark, cloudy and rainy for many days, even though they were not directly in the line of rain, it is still extremely humid and moist out there! We had rain for 7 or 8 days straight (24" total in that time), and have had showers and storms each day since, with the exception of one or two days. The covered deck attaches to the swimming pool deck and with all that water and the non stop rain, it has been very soggy and humid.
So, for a few weeks, my plants have had inadequate light levels, very cloudy conditions and too much moisture in the air. I haven't removed the affected leaves yet but will plan on doing so in the next day or two. Summer is here so we will be experiencing the daily afternoon storms and rain normal for Florida this time of year ... I might end up moving my hoyas inside the house!
I was finally able to talk to them. I have to send pictures and one or two leaves along with a form that I'll download form their web. There is a $30.00 charge but I'm willing to pay because I want to know what it is. I'll send it latter today and when I get the report I will be happy to share here and email a copy of it to whoever wants it. I have no idea how long it will take, the lady didn't say.
Here is their website.
Lourdes
http://plantclinic.tamu.edu/
Lin,
if you want you could send me a leave ( I was told just to put it in a zip lock bag no thing else) And once I get it I can send it along with my samples. The lady said the more I could send the better. Let me know if you want to do it.
Dominic,
you are very far away but I'll share with you the results.
Lourdes,
Are you in the address exchange?
I will gladly send leaves from blashernaezii and obovata, as well as the peperomia plant. I will also split the $30 fee with you, to try to find out for certain what this stuff is! It may be normal or nothing to worry about but I am concerned that if it completely covers both front and back of all leaves, they won't be able to breathe, and the plants will die. I also worry about the possibility of it spreading. Whether it is harmful to the plant or not, it will be interesting to know exactly what it is.
I am going to check to see if you are in the addy exchange!
Lin
Lourdes, I didn't find you in the address exchange so shoot me a d-mail with the address and I will get these in the mail to you.
Thanks!
Lin
Lin.
I just sent you a d-mail ;)
Thank you
Lourdes
Whats on mine starts off like a fine grey/brown film like yours looks like Lin, under the leaf and then it has progressed to be much thicker and corkier and now on the top. I do have it started on a 3 or 4 other of other Hoyas too, so Im presuming it will become much thicker on those too. Ive noticed it on the more succulent leaves, and not on any other plant. With regards to the age discoloration on Cacti, in its initial stages it does kinda resemble this, but this is new leaves and it thickens up differently to old cactus growth basal growth. Personally I had put it down to environmental issues as mine are outside, but maybe this is spreading. It can happen on Papaya skin too, butnot quite as ugly Any advice would be grateful Lourdes. Sorry I cant send a leaf that far, but I owe you one...probably more than one favour back in fact....;))
Dominic
This message was edited Jun 8, 2009 4:51 PM
I just got the leaves that Lin so kindly sent me, I will send hers and mine this afternoon to the university. Looking at her leaves and mine together, I have no doubt in my mind that both plants have the same condition, (whatever it is).
Will see what they say.
Thank you Lin!
Lourdes =)
Lourdes,
You are welcome! Will look forward to hearing what they determine the stuff is and whether it is a natural occurence or something that should not be growing on the hoyas.
Hi,
has anyone tried to look at a damages leaf with an hand lens?
I think its spider mites, they can make a corkish layer on a leaf surface.
/Maria
Hi Maria,
I used a magnifying glass, but I couldn't see anything at all. . . I treated it with fungicide as well as insecticide and did not change.
Will post here the results from the university as soon as I get them.
Thank you,
Lourdes =)
I noticed something the other day on a couple of plants ....there was what looked like the beginnings of this brown stuff on the outer edges of the underside of the leaves. Ants were going backwards and forwards obviously milking whatever they were. If its the same thing, at this stage it was soft and squashy and the critters minute........could be something else, but the color is the same. Sprayed those plants again, and seems to have killed whatever it was....just a thought
Dom
Still waiting for the results. . . we'll see. I know for sure that in my case, is not ants, I have them indoors.
Lourdes =)
Mine are outdoors and we have lots of ants here in Florida but I haven't seen any ants on or around the hoyas.
No, I didnt mean ants, what I meant was the ants were milking some other tiny insect, like they milk mealies and greenfly,and they were miniscule, but very plentiful
Oh, OK sorry I misunderstood. .. when the "crust" first started to appear, I checked them with a magnifying glass and I could not see any bugs at all . .. hopefully, we'll know soon.
Ok Folks: We have the answer to what the growth is on the reverse side of our Hoya leaves. Lourdes was so kind to send a few of our leaves of H. blashernaezii to Texas A&M University for diagnostic testing and has received the report back from them which I am copying and pasting below. It's very good to know that it's not anything harmful and I offer a huge Thank You to Lourdes for taking the initiative to contact the University to get answers for us! The following is the report in full with the exception of me deleting Lourdes personal information (home address, home e-mail etc.) that she had to supply on her inquiry to the University.
Lourdes, Thanks so much!
Lin
__________________________________________________________
Texas Plant Disease Diagnostic Laboratory - Diagnosis Reply Letter
Wednesday, July 08, 2009 11:15 AM
Subject: Plant Specimen Diagnostic Report
Texas Plant Disease Diagnostic Laboratory
1500 Research Parkway
Suite A130
http://plantclinic.tamu.edu
College Station, TX 77845
Phone: 979-845-8032
PLANT SPECIMEN DIAGNOSTIC REPORT
Specimen # 614
PLANT: Wax Plant
METHOD SUBMITTED: MAIL
CLASS: ORNAMENTAL - Herbaceous
LAB FEE: $30.00
PLANT MATERIAL: LEAVES
SENDER CATEGORY: HOMEOWNER - individual
CONDITION UPON ARRIVAL: GOOD SAMPLE, COMPLETE FORM
DIAGNOSTICIAN: S.McBride - Extension Program Specialist
GENERAL OBSERVATIONS: 4 detached leaves with lesions on underside of leaves
DIAGNOSTIC TECHNIQUE(S): SPECIALIZED MEDIA, MICROSCOPE,TISSUE EXAM,CULTURE
Diagnosis:
Suspect Oedema
Category: STRESS - environmental/cultural
Comments: Lab Summary: no evidence of fungal structures, no evidence of bacterial streaming
Oedema is a physiological disease that results in the development of blister-like lesions across the leaf surface. Lesions are usually most prominent on the lower leaf surface. Oedema results from excessive water pressure developing in the leaf tissue during conditions of high soil moisture, high relative humidity, and low light. These conditions generally minimize the movement of water out of the leaf tissue and, when the soil remains saturated, the excessive water pressure which develops in the leaf tissue results in blister-like lesions. When the plant water relations re-establish to optimal levels, the lesions will collapse and dry, resulting in a crusty, brown, scab-like lesions. Oedema is a physiological condition which results in loss of aesthetics, but does not represent a serious hazard to the plant's health.
Control of physiological oedema consists primarily of reducing watering during periods of cloudy, cool, high relative humidity weather. A well-drained potting medium will minimize excessively wet soils. With time, most plants can adequately outgrow the affects of oedema.
**********************************************************
The diagnosis and recommendations above are based on the submitted specimen and information accompanying the submitted specimen, and may not be representative of the entire field or planting. The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by the Texas Plant Disease Diagnostic Laboratory and/or Texas AgriLife Extension Service is implied. Brand names of pesticides are given as a convenience and are neither an endorsement nor guarantee of the product nor a suggestion that similar products are not effective.
This message was edited Jul 8, 2009 2:38 PM
pssst...Lin...you need to remove the ___ to get this thread back to its normal size...LOL
Great information! I sincerely want to thank Lourdes and Lin for their work on this issue.
Doug
You are welcome Lin and Doug!
I'm very relived that is not a disease , I also want to thank Lin here-- I did by email because she will be splitting up the cost of the diagnostic with me.
I hope this can useful to all of us.
Lourdes =)
Oops ... fixed! Thanks ThreeG!
Doug: The Thanks all goes to Lourdes who spent her time and money to get the report! All I did was condense it and post it here!
Whew! We can all breathe a big sigh of relief now, knowing for sure it's nothing serious on our Hoyas!
And ... it looks like podster was right on when she commented about Oedema in her post on June 8th!
Lourdes, I am sending you half the cost for that report. It sure is well worth it to me, knowing for certain what the stuff is. I'm very glad it isn't anything detrimental to the plants since more than one seem to have it.
Excellent Lourdes..thanks so much for checking that out, and for your help too Lin.
Owe you one
Dominic
Lin,
thank you; I told you that you didn't have to split up the cost, but I know that I will not change your mind (lol) I really appreciate it.
Dominic,
I'm glad it will help us, like Lin said, it was well worth.
Lourdes =)
Good to know it isn't serious but only cosmetic. Now, I wonder about your plants Lin ~ you said the Peperomia has been very dry and your affected Hoya plants hadn't been overwatered. What do you think caused this?
LOL, Pod ... I have no clue. I am the worst about NOT taking good care of my plants. I have tons and tons of plants and mostly they just do their own thing with me turning the hose on them a couple of times a week if they are lucky.
The Hoya was on a plant stand, in a corner under the covered deck and there were quite a few plants crammed in there together. It's very, very humid here year round and with the swimming pool out there, there's lots of moisture in the air. We've had a ton of rain the past two months too. I'm assuming the reason for the oedema on my plants is because of:
Location of plants affected: very low light, shaded by plants crammed together.
Poor air circulation in that area, from so many plants crammed together!
High relative humidity, which is common here year round.
The additional moisture from the all the rain we've had the past couple of months, 23" in May alone!
I do use a very quick draining mix for almost every plant I own, (a combination of lots of orchid bark, perlite and a little potting soil but the mix is mostly the orchid bark mix that has charcoal, perlite and bark in it.) Even with the light, fast draining mix I guess the oedema might be caused by the combination of not enough light, too damp/wet and not enough air ciruclation.
The peperomia was in a little bit heavier mix, with more soil than bark but still drains quickly. It was in the same location on the deck. The obovata I found the oedema on was also on that same plant stand. That particular plant stand sits up against a wall in a corner of the deck. There's a roof over the deck, screened on one side but there are plants hanging from plants, hanging from plants in front of that screened area, and so many plants blocks a lot of the airflow. I need to re-arrange.
My main problem probably is the lack of enough air circulation in that area of the pool deck. I keep saying I need to downsize the number of plants I have and just concentrate on one or two types ... but it's so hard to do! I never met a plant I didn't like (well, maybe one or two, LOL) ... especially if they have sharp thorns! ^_^
LOL ~ I agree on the thorns! You DO have lots of plants, at that rate I can see how difficult it would be to fertilize on a regular basis. Lins' Jungle!
You hit on the one thought I had for the oedema cause. That would have been air circulation which would aid in evaporation. I guess you won't know but I am glad it wasn't serious for everyone. pod
Fans help, Lin.... Especially when they are moist, wet, damp. I try to water or mist when the morning breeze has come up...
To both/all of you who found the solution: a gazillion mahalos!!!! I am printing all of this out and it is so helpful!!! Many thanks!
Carol
Lourdes,
I missed the mailman today. We don't normally get our mail delivery until 2:00 or later in the afternoon and he came early this morning for some reason. So, my note with the check for you are sitting on the kitchen table for tomorrow's mail. Thanks so much for sending our leaves off to Texas A&M and letting me share in the cost of the testing!
Lin
Thank you Lin! I really appreciate it, you didn't have to do it. Don't worry there is no rush.
I'm glad that we were able to send leaves from different plants thanks to you. I'm also very happy of the outcome, and the fact that the information can be helpful for future reference.
Lourdes =)
Hello Lin,
I received the check and the note that you sent. Thank you so much for the note . . .you are quite a lady!!!
Take care.
Lourdes
Lourdes,
Thank You! It's great to know we have nothing serious affecting our plants! I appreciate you taking the initiative to send our leaves to the University for examination! If they end up charging you any more than the initial $30, please let me know, okay? I want to go 50/50 for the expense.
Lin
Thank you Lin,
I'm sure that is the total cost, but I’ll let you know if there are additional charges as soon as I get the invoice.
I really appreciate it.
Lourdes =)