what can substitute physan 20? mold is present, phal is in bloom

[chemist]

Hello all!
What can substitute physan 20? If I order one today (Monday) it will arrive only on Friday. I noticed mold inside the pot on the root today and something on the media on the bottom of pot. Mold on the root was not there last Thursday when I left work. Unfortunately there was no light in a room for at least two days, I guess that provoced mold to grow.
Can my phal survive till Friday?!
Orchid is in bloom. Can I repot it in this stage?! Some of you here are saying no-no to repot while it's in bloom, some are saying it was OK.
Also present media is coconut bark but too me it looks broken down and it probably really needs to be repotted.
Thank you in advance for your reply!

[kspalding]

It seems like its about spent and will soon need to be repotted anyways. My personal opinion is to just wait since the plant doesn't seem to be too stressed over it and repot once it drops its blooms.

[78Terp]

There are some references to mold in this link to home remedy's, if it makes it past the censors here.

Home Remedies | First Rays Orchids

[Catt Mandu]

I see what looks like broken down medium (black particles) in the pot, but not anything that is clearly mold or fungal disease. The discoloration on the root tip also does not look like a fungal problem.

I think people are sometimes too quick to use Physan or other chemicals. I've been growing orchids for 30+ years, I have never purchased or used Physan. Instead of chemicals, I would suggest that you remove the root mass from the pot (should be easy, but probably there will be slight damage to some of the roots that have gone through holes in the pot; this won't hurt the health of the plant). When the root mass it out, run the roots under running tap water to rinse out decomposed potting medium (the decomposed medium looks like potting soil; if in the sink, run the water into a bucket to avoid clogging the sink).

After rinsing, let the roots dry outside the pot for a few hours, then you have a couple options. (1) Remove any remaining old medium from the roots and re-pot using whatever growing medium you like (if you are not sure, I recommend bark-based orchid medium). I re-pot most of the Phals I buy that are blooming into new medium as soon as I get them home, it does not hurt the blooms at all. Repotting is much less damaging than roots sitting in decomposed medium. (2) If you can't re-pot, after rinsing the roots & allowing them to dry (maybe 3 or 4 hours), put the root mass back into the same pot until you are able to re-pot.

Good luck!

[chemist]

I see what looks like broken down medium (black particles) in the pot, but not anything that is clearly mold or fungal disease. The discoloration on the root tip also does not look like a fungal problem.

I think people are sometimes too quick to use Physan or other chemicals. I've been growing orchids for 30+ years, I have never purchased or used Physan. Instead of chemicals, I would suggest that you remove the root mass from the pot (should be easy, but probably there will be slight damage to some of the roots that have gone through holes in the pot; this won't hurt the health of the plant). When the root mass it out, run the roots under running tap water to rinse out decomposed potting medium (the decomposed medium looks like potting soil; if in the sink, run the water into a bucket to avoid clogging the sink).

After rinsing, let the roots dry outside the pot for a few hours, then you have a couple options. (1) Remove any remaining old medium from the roots and re-pot using whatever growing medium you like (if you are not sure, I recommend bark-based orchid medium). I re-pot most of the Phals I buy that are blooming into new medium as soon as I get them home, it does not hurt the blooms at all. Repotting is much less damaging than roots sitting in decomposed medium. (2) If you can't re-pot, after rinsing the roots & allowing them to dry (maybe 3 or 4 hours), put the root mass back into the same pot until you are able to re-pot.

Good luck!

Dear Catt Mandu, thank you for advise!
Could you please take a look at close up picture, I'm pretty sure it's mold, the same like you can get on bread etc.
Also how long I need to soak bark I have fir bark and mix of bark with moss and perlite (what do you think better to use)?
If im not able to repot after drying roots for few hours as you suggested how long phal can stay with no media? Also do you think I need bigger pot or repot in the same one?

[Carolla]

What causes people to say wait to repot is that stress may cause the plant to drop its flowers. If the plant is happy probably not. If the roots are bad or the medium is really broken down, then you may need to repot immediately on the thought that keeping the plant happy is more important than the current flowers. I don't think the roots look all that bad though, you could probably wait. However, do let it dry out pretty thoroughly before you water again, that will help any mold problems. Mold in the root area means too much water, but the roots look fat and green, so I don't see a lot of damage there. I'm not so sure either that I'm seeing mold, though can be hard to tell in a picture.

When you repot a plant and it is into different media than used before (and there will be a change from broken down bark to fresh, so that counts too), the existing roots can't really adapt to the new environment, so the plant will be stressed from that. New roots will actually grow with a different structure to handle the current growing environment, so the plant will take a while to recuperate. Because of that, I generally repot when there is new root growth that can adapt itself to the new circumstances. However, emergencies over ride that. Hopefully that will be helpful in sorting out when to repot your orchid.

[Catt Mandu]

Dear chemist:

OK, now I am seeing what you are seeing (blue-green and white). I could not see it before.

I would just go ahead & re-pot after removing all the old medium & rinsing off the roots with tap water. I do this all the time with Phals, it does no harm to them, even when blooming. They are tough.

I would use the plain bark (without moss/perlite). You can soak the bark for an hour or so before re-potting, but to be honest, I don't bother soaking bark when I re-pot most of my epiphytic orchids, including Phals. The plants seem fine with this (even in bloom). The existing pot may be fine, or you could go just a little larger (only a little). If you re-use that pot, wash it really well (detergent, hot water, rinse well, or you can use some dilute bleach and then rinse well). If you go larger, I have a personal preference for terracotta pots, but I know some people really like the plastic ones so that they can see the roots.

Regardless of the type of pot, whenever you water, you should water the bark & roots thoroughly (but not the leaves), water should flood through the pot (water at the sink). The bark should be nearly dry (just very slightly damp) each time before you water again. This probably means you will water less often, maybe once a week, maybe twice a week. If the roots and medium don't stay as wet, it will discourage mold and you will keep more of your roots in good condition.

I didn't mention it before, but very nice white Phal! Good luck.

[chemist]

Dear chemist:

OK, now I am seeing what you are seeing (blue-green and white). I could not see it before.

I would just go ahead & re-pot after removing all the old medium & rinsing off the roots with tap water. I do this all the time with Phals, it does no harm to them, even when blooming. They are tough.

I would use the plain bark (without moss/perlite). You can soak the bark for an hour or so before re-potting, but to be honest, I don't bother soaking bark when I re-pot most of my epiphytic orchids, including Phals. The plants seem fine with this (even in bloom). The existing pot may be fine, or you could go just a little larger (only a little). If you re-use that pot, wash it really well (detergent, hot water, rinse well, or you can use some dilute bleach and then rinse well). If you go larger, I have a personal preference for terracotta pots, but I know some people really like the plastic ones so that they can see the roots.

Regardless of the type of pot, whenever you water, you should water the bark & roots thoroughly (but not the leaves), water should flood through the pot (water at the sink). The bark should be nearly dry (just very slightly damp) each time before you water again. This probably means you will water less often, maybe once a week, maybe twice a week. If the roots and medium don't stay as wet, it will discourage mold and you will keep more of your roots in good condition.

I didn't mention it before, but very nice white Phal! Good luck.

Thank you Catt Mandu!

Since I work in food testing lab and we have microbiology department where they test all type of fungus, bacteria etc I ask our microbiologist what she can suggest how to treat mold... She suggested 10% bleach. And than rinse it thoroughly. Does anybody has opinion on her suggestions ? She and I do understand its might be not good idea for orchids.


When you say flood the pot, how long let water go over the pot? About 1 min, 5 or more? Some people submerge pot in water and let stand for half an hour.
What is the best practices?

If I will need to cut some roots do I need apply some cinnamon on the cuts?

[Catt Mandu]

I suggest skipping the bleach (may damage roots). Just repot and you should be fine.

If you break a root or need to cut a root, just let it air dry (no cinnamon).

For watering, let water flow through the pot for a minute or less. Some people do soak the roots in a container for a minute or so, but with a newly-potted orchid, this may float the bark out of the pot. Soaking is fine for plants that are well established and rooted in their pots.
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[raybark]

Being a chemist, it's pretty natural that your first inclination is to treat with a chemical (believe me, I understand - I've worked in the chemical industry for over 35 years), but that is treating the symptoms, not addressing the problem. If you must do so, and can't wait for the Physan, one ounce of bleach per gallon is the appropriate rate, not 10%.

I'm with Catt - don't use cinnamon on roots. It's a marvelous fungicide, but it's also a desiccant, and can be damaging.