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09-05-2021, 05:17 PM
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Senior Member
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Join Date: Jun 2015
Zone: 9b
Location: Phoenix AZ - Lower Sonoran Desert
Posts: 18,586
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Welcome to the Orchid Board!
I agree it has an excellent chance of recovery. I do not see any stem rot, no leaf rot and no crown rot. The older, leafless portions of Phalaenopsis plant stems eventually die, turning firm and brown. The upper growing portion of your plant looks OK. Some people cut off rootless portions of old stems and others leave them to fall off naturally. I would not cut the flowering stem. I think your plant has enough water reserve to keep it alive until it grows more roots.
Phals require air at the roots. The old medium I see is denser than I would use for a Phal, with too little aeration. This is likely why the roots rotted, not overwatering. Look for something that will have air spaces throughout the medium. With plenty of air spaces in the medium Phals can be watered frequently.
What kinds of potting media can you get? They can easily be grown in chunks of volcanic rocks like pumice, cinders or scoria, or any other rocks with diameters between 75-150mm, smaller if your humidity is lower. Fired clay spheres called LECA work well. They are sold for horticulture under the brand Hygroton and others. Bottle corks can be used if made from tree cork. Where I live the rocks and soil are mostly granite. If I could not buy media I would use pebbles about a centimeter in diameter for my epiphytic orchids, like Phals. Here is a photo of a Phal in LECA:
What are the temperatures and relative humidity in your growing area?
Root stimulators can help if not overdosed, but your plant is healthy enough it should recover without them. I don't know the appropriate dose of IBA.
The most important factors for getting Phals to root are warm temperatures and high humidity. If your ambient humidity is low you can put it into a large jar or a transparent plastic bag.
Phals don't ever need sun shining on their leaves. Bright shade is fine.
Last edited by estación seca; 09-06-2021 at 01:59 AM..
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09-05-2021, 06:31 PM
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Jr. Member
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Join Date: Aug 2021
Posts: 16
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Quote:
Originally Posted by estación seca
Welcome to the Orchid Board!
I agree it has an excellent chance of recovery. I do not see any stem rot, no leaf rot and no crown rot. The older, leafless portions of Phalaenopsis plant stems eventually die, turning firm and brown. The upper growing portion of your plant looks OK. Some people cut off rootless portions of old stems and others leave them to fall off naturally. I would not cut the flowering stem. I think your plant has enough water reserve to keep it alive until it grows more roots.
Phals require air at the roots. The old medium I see is denser than I would use for a Phal, with too little aeration. This is likely why the roots rotted, not overwatering. Look for something that will have air spaces throughout the medium. With plenty of air spaces in the medium Phals can be watered frequently.
What kinds of potting media can you get? They can easily be grown in chunks of volcanic rocks like pumice, cinders or scoria, or any other rocks with diameters between 5-20mm, smaller if your humidity is lower. Fired clay spheres called LECA work well. They are sold for horticulture under the brand Hygroton and others. Bottle corks can be used if made from tree cork. Where I live the rocks and soil are mostly granite. If I could not buy media I would use pebbles about a centimeter in diameter for my epiphytic orchids, like Phals. Here is a photo of a Phal in LECA:
Attachment 154194
What are the temperatures and relative humidity in your growing area?
Root stimulators can help if not overdosed, but your plant is healthy enough it should recover without them. I don't know the appropriate dose of IBA.
The most important factors for getting Phals to root are warm temperatures and high humidity. If your ambient humidity is low you can put it into a large jar or a transparent plastic bag.
Phals don't ever need sun shining on their leaves. Bright shade is fine.
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Thanks so much. The medium underneath the orchid is coconut husk chips mixed with perlite and horticultural charcoal, however, my coconut husk chips are not that large in size so it is not that well-draining. Here we have pumice so maybe I'll try to get some and break it into pieces (they only have very big pieces like the size of a hand). Or else I'll try to just use some pebbles. Would adding some sand help?
I'm in Cairo so the humidity is pretty high this time of year 45% to 77% and the temperature indoors is probably around 27-35 degrees celsius. I'm not sure about my humidity indoors though.
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09-06-2021, 01:56 AM
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Senior Member
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Join Date: Jun 2015
Zone: 9b
Location: Phoenix AZ - Lower Sonoran Desert
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The temperatures are excellent for Phals. Humidity 45%-77% is fine. The humidity may be higher indoors due to the breath of the people.
Phalaenopsis, like many other orchids, are epiphytes, meaning they grow on tree branches with their roots normally moist and exposed to air. The air at the roots is the most important aspect of growing epiphytic orchids. Sand has small particles, and would fill in the air spaces between larger chunks of medium. That is exactly what you don't want. Potting mixes good for terrestrial plants suffocate orchid roots quickly. Gardeners who haven't grown epiphytes before need to rethink what potting mix should look like, but it it doesn't take long to understand. Browse through Orchid Board looking at photos of plants in various media to get an idea of the particle sizes and air spaces common with orchids.
Pumice chunks or pebbles +/-1cm in diameter should work well. Screen out the fine particles so only chunks are used. Don't breathe the rock dust. It doesn't matter whether the medium has smooth or rough surfaces. The pumice might be a little better because the tiny openings in the pumice would retain some moisture and humidity longer than with smooth pebbles.
Plain horticultural charcoal or perlite alone can also work if the chunks are larger, +/-1cm in size. This might not be available to you. I would not use either of these if the particles are the size I see in the earlier photos. Those pieces are too small and there won't be enough air at the roots. Perlite floats, so when you water a plant in perlite you must be careful, or it will float out of the container.
Edit: In my earlier post I suggested particles 5-20mm. I don't know what I was thinking; 5mm is too small. I would aim for 75-150mm. I will go back and change that post.
Last edited by estación seca; 09-06-2021 at 01:59 AM..
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09-06-2021, 10:27 AM
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Jr. Member
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Join Date: Aug 2021
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Quote:
Originally Posted by SouthPark
The recommendations about not using hydrogen peroxide on roots is a pretty good one in my opinion. And - for rot situations ----- could possibly consider phosphorous acid treatments (eg. monterey garden phos, which is 'systematic') ----- or maybe non-systematic copper solution spray all around region that is beginning to rot. It all depends on how advanced the rot is, and whether the treatment is appropriate. Totally agree with air-movement. That can be beneficial as well - and also cuts down on chances of getting to conditions that lead to rot.
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Update on how the stem looks today. I feel like the black part of the stem is advancing. Are there any household products I can use as a fungicide instead of buying something? Can I use a baking powder solution or will that be too alkaline?
:/
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09-06-2021, 10:56 AM
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Senior Member
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Join Date: Feb 2009
Location: Baja, Hungary
Age: 40
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Well it looked like stem rot to me on the previous pics as well.. And I've used hydrogen peroxide before on the whole plants and not roots were damaged for me, in fact those plants are the best growing ones i have now. MissOrchidGirl suggests in her videos that it is a proper fungicide. Of course it's just one opinion, i'd be curious to learn and hear counter opinions myself as until now i believed it to be safe to use.
Regarding your orchid if you say it's still spreading.. i don't see any harm in at least trying it at this point..
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09-06-2021, 04:59 PM
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The St Augustine Orchid Society Web site[/URL] has a section on orchid diseases. What you have might be collar rot or sclerotium. The article says it can result from keeping plants too wet in organic media during periods of high temperatures and humidity, which matches the plant's recent history. The roots don't have the characteristic look of fusarium-infested Phal roots described in the article. The article describes care of affected plants, including suggested fungicides for collar rot.
Hydrogen peroxide doesn't penetrate into the tissues where the rot is. I would only use it for crown rot where the newest, smallest leaf is beginning to rot. The plant has only two small roots; I would not risk damaging them by treating with hydrogen peroxide.
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09-06-2021, 05:15 PM
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Jr. Member
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Join Date: Aug 2021
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Quote:
Originally Posted by estación seca
The St Augustine Orchid Society Web site[/URL] has a section on orchid diseases. What you have might be collar rot or sclerotium. The article says it can result from keeping plants too wet in organic media during periods of high temperatures and humidity, which matches the plant's recent history. The roots don't have the characteristic look of fusarium-infested Phal roots described in the article. The article describes care of affected plants, including suggested fungicides for collar rot.
Hydrogen peroxide doesn't penetrate into the tissues where the rot is. I would only use it for crown rot where the newest, smallest leaf is beginning to rot. The plant has only two small roots; I would not risk damaging them by treating with hydrogen peroxide.
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So do you think I should cut off the stem up to the rotted part? I'm really worried about cutting off the only remaining roots :/.
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09-06-2021, 05:24 PM
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Senior Member
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Join Date: Jun 2015
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I would try to find one of those fungicides, cut off the stem under the living root, and use a razor blade to shave the brown part down to green tissue. Sanitize the razor blade between each cut with alcohol or a solution of bleach diluted 1 part bleach to 9 parts water. The problem is the creamy yellow part represents infected tissue. It is very close to the growing point of the plant.
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09-06-2021, 05:38 PM
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Super Moderator
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Join Date: Jun 2008
Zone: 10a
Location: Coastal southern California, USA
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Don't cut the roots! That would remove any possible chance of survival! The stem below the roots, where it is brown, could be cut, but for right now, no harm at all in leaving it alone. That plant has received enough insults... Now, just give it good care... there is some excellent advice in this thread as to how you can provide air to the root zone and maintain humidity. Until it grows some more roots, there is no additional treatment that will help, roots are the only way that the plant can take in water. The high humidity will simply help to maintain it by reducing water loss through the leaves until it does recover the root system.
---------- Post added at 01:38 PM ---------- Previous post was at 01:26 PM ----------
The advice from ES (which came in while I was writing my comments) with regard to alcohol or dilute bleach is very good... he's right, the rot is pretty close to the growth area. Just be very careful with your cuts - go slowly, a very little at a time so that you don't accidentally healthy tissue.
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09-06-2021, 05:42 PM
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Jr. Member
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The problem is if I remove the rotting part the roots will go too. I'm worried about setting it back even more. Unfortunately, I don't have a proper fungicide and I don't think it's easy to get one here.
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