Orchid stopped growing, leaves drooping, roots drying - Orchid Board

dreamynights · #1 08-18-2013, 05:41 PM

Hey all,

I need some help with my orchid. Around June, my orchid lost an old leaf and started growing new leaves/roots, which I was very happy about. There was a lot of growth, until around one month later in July, some type of mold grew on the dead leaf near the crown. I used hydrogen peroxide 3% to get rid of it. There was a little more growth after this but then I also started getting major gnat issues. It seems like the plant completely stopped growing and I noticed a slight droop on the lowest leaf. I have been trying to water less to control the gnat problem so I am unsure if that caused minor drop on the leaves. I did a couple weeks of soap spray and more hydrogen peroxide to try to get rid of gnats and their eggs.

In late July, since I couldn't seem to solve the gnat problem, I had to repot the plant. The plant was originally in about 70-80% moss. It seems like all the old root were completely rotted and only the new roots were the surviving ones. I decided to replant in mostly bark (about 80%) to keep the plant from getting too wet again. I soaked all the medium and the plant in 1 Tablespoon PHYSAN 20 per gallon of water - which is according to the dividing plants/rot directions.

After repotting, the condition of my orchid have been getting worst and worst. The leaves are almost completely drooping and this weird brownish stain, almost like rust is appearing on some of the roots. Although the roots near the surface are still full, I can see that some of the roots deeper in the pot are turning yellow, cracking or shriveling up. My plant has also been drying up too much, roots became white after full waterings within 2-3 days. I would water on Sunday and have to water again on Wednesday. This happened for two weeks and there have been no more root growth. Last week, instead of watering normally, I tried to just mist the plant every day to promote root growth but it did not work. Today I added more moss to the plant so there is about 60%bark/40% moss and will water regularly again. Pics are attached.

Here are some questions I have:
1- What is the browning on the roots? Did the hydrogen or Physan 20 harm my roots somehow?
2- Since the leaves are still green, does the drooping just mean the plant needs more water? If this is the case, why do the roots seem to be dying from rot?
3- Is it normal to have roots stop growing in August or is my plant stressed out? What are other ways to promote root growth?

dreamynights · #2 08-18-2013, 05:43 PM

Forgot the attachments.

Bill U. · #3 08-18-2013, 08:08 PM

Alright, so let me make sure that I understand your timeline here:

1) Your phal was originally potted in mostly sphagnum moss and you were having some gnat issues.
2) Mold was appearing around July in the area that the old leaf fell off and by the new roots that were popping out
3) roots stopped growing and you had repotted into a mostly bark mix to help it dry out

If this is incorrect, please let me know so we can better help you.

First of all- phals in all or mostly sphagnum potting mixes normally have some problems in the average home for indoor culture because in many cases, it won't dry out enough in the middle of the rootball before they get watered again (because their owners will look at the top that is all dry and think they need to water again). This being said, that continual wetness with little to no air movement is a huge promoter of root rot.

I think that you did a good thing with removing it from the old potting media and treating it with the Physan. I personally cannot advise on the amount of Physan you used, because I have never used it myself. However, in theory that should have taken care of most of the fungal rot.

With the drooping- that can be an indicator that you phal is still thirsty. And there also can be the issue that once they get too droopy, they normally don't fully recover to their original firmness. The thirst factor can come from a couple of different things:

Not enough roots to sustain the amount of foliage that you have on the top of the plant (from the original rotting problem)
the roots are having a hard time absorbing and maintaining moisture levels because they are not used to the bark mixture that is much drier. *When roots of orchids grow, they adapt to their environment, whether it be on the drier side (phal air roots) or more on the moist side (sitting in sphagnum or S/H). But once the roots are formed they are extremely limited in the amount of change in the cultural conditions they can handle without having consequences. In your case, your current roots may be rebelling against the sudden change to such a dry environment (even though it doesn't know it is for its own good).

The best way to control thirst and make sure that your roots are not too wet for too long is to use a clear plastic pot for your phal. That way you can see the majority of the roots and their status. When the roots are bright green- they are full of water and don't need any for a while (usually a couple of days in the average home), but when they turn a light silvery color- that is time to water and give a thorough drenching, but still allow the pot to drain out some (some growers suggest 15 min or so).

As for coloration on the roots, sometimes that is just from the change from moist environment into the bark. Some members on OB have remarked that a fair number of their phals will have this happen when using mostly bark as their potting medium. I personally have this happen with a fair number of my roots on my phals and it does not seem to have much of an effect on the overall health of the plant. Older roots will get more of a yellow color and can dry out until they are woody in appearance, but that is part of the natural cycle of senescence- as the plant decides that root or leaf has used up its vitality and is no longer functioning optimally, the plant will often suck the nutrients that structure has back into the main body to use for making a replacement.

After all of this I would say that your plant has been stressed out and not to worry too much about those little nubs of roots- orchids are masters of efficiency; if they cannot sustain a particular growth at that time, they will put it on the back-burner or just say "Stop! That's all I can handle right now." If you are looking to induce roots, I suggest that you either purchase rooting hormone (such as Superthrive) or use a seaweed extract (Maxicrop, Kelpmax, etc) to use as a root stimulant. The seaweed extract has rooting hormones to induce roots but also has other general growth hormones that help orchids and just about all plants flourish! Of course, giving it regular feeding with fertilizer helps as well!

Sorry for the novel, but please don't hesitate if you have any further questions!

dreamynights · #4 08-24-2013, 04:42 PM

Hey Bill,

I loved the novel, it was very helpful!

Since I added a bit more moss last time, the roots remained green a little longer, for about 4 days. I just misted them for about 2-3 days after that because I would like to be watering once a week during the weekends when I have more time to do full drenches. When I was misting, I noticed that some of the roots absorbed water a lot faster than others. Some roots would instantly go green, but one or two in particular remained white. When I put a droplet of water on it, it would sit there for about 3-4 mins before going a tiny bit green. That root is the one shown in the images above with some discoloration. It seems to have a really thick outer layer. I'm curious if this is because the plant is getting rid of the root and not absorbing much from it. Today I did see a small root popping out of a browning root so Im happy there is some sign of growth!

I still see some bugs in my new medium but no flying bugs so hopefully I got rid of the gnats. There were very small jumping bugs in the water tray. They are oval but a long oval and not actual oval like mites. They are silvery and sometimes black so I believe they are springtails? Previously I have seen these in my old medium, along with mites and the gnats. I havent seen anymore mites or flying things so hopefully the gnats are gone. I think these are from my bag of bark but was hoping that the Physan 20 would kill them. Guess it doesn't but at least if they are springtails, they should be harmless! I won't try anything further until I see annoying flying gnats. I dont want to repot my medium again or use chemicals since my plant is already stressing out

Thanks for your help!