HELP! Fungi on Coco Husk + Some more problems!

[holatombola]

Hi everyone,

Problem 1:

Today, I looked at the Coco Husk Chips in which I plant all my orchids. In this case, I looked at my Brassia 'Chieftain' and I saw green fungal growth on one of the larger chunks. I am sure it is not algae, hence I am sure it is fungi.

My watering schedule is:
To water the pot(s) by soaking them for 5-10 seconds when they feel light (i.e. Less weight due to less water absorbed in the Husk), or when the plants show signs of needing water (i.e. Wilted leaves), although I never leave them dry enough for the leaves to wilt.

I use net pots so why is this fungus problem occurring, as I bought them specifically to allow some air circulation...

What am I doing wrong?!

Problem 2:

When I look at my orchids, they are all healthy as such to look at (i.e. No pests or damage, or signs of distress). However, the roots of almost all my orchids are dying. Well, I feel they're dying/dead because e.g. My Baby Phal's roots are green and living, and the plant is fine, but there seems to be a dead bit between the green root and the plant. So I am wondering how the plant is surviving. The Brassia's leaves are not green, at all really.

Do you think I should change potting medium? Could you suggest a better watering schedule?

[Ray]

Green molds are not nearly as common as algae. How are you so sure it's not the latter?

On the second question, describe the "dead bit" in the middle. On many orchids, particularly phals, there is a layer of dead tissue on the surface of the root, except for the green, growing root tip. That layer of dead cells, called "velamen", acts as a sponge to soak up and hold water and nutrient solutions for slower transport to the living root cells below. Sometimes other contaminants can be absorbed as well, giving the velamen a dead, brown appearance.

[holatombola]

I'm sure because the growth was not covering the entire piece of husk, there were individual protruding growths. I could clearly see the mushroom cap type shape, be it small. Perhaps a greyish green colour would be more accurate.

The dead bit is not velamen, as the whole root shrinks into the dead bit. The dead bit is shrivelled and brown in colour. To give you a picture, imagine the small healthy green root on the right, connected to the plant by a small 'dead bit' right on the base of the plant from which the root comes out. Hope that clears things up.

[kmarch]

Originally Posted by holatombola

Brassia 'Chieftain'

Don't put quotation marks around the grex (hybrid name). quotation marks go around the cultivar name only, so : Brassia Chieftain. The International Orchid Register / RHS Gardening

Originally Posted by holatombola

I saw green fungal growth on one of the larger chunks. I am sure it is not algae, hence I am sure it is fungi. What am I doing wrong?!

I don't necessarily think you're doing anything wrong. Mold and algae isn't a bad thing; it's not necessarily a problem that needs to be solved. Whenever you have air, moisture and some sort of gradually decaying organic material (like orchid potting mix) you're almost certain to have some sort of mold whether you can see it or not. I don't worry much about molds that show up in potting mixes. Fungal attacks on leaves are a different story but, although I am no expert on molds and fungi, I understand they are different form the kind of mold that shows up in potting mixes.

Originally Posted by holatombola

My watering schedule is:
To water the pot(s) by soaking them for 5-10 seconds when they feel light (i.e. Less weight due to less water absorbed in the Husk), or when the plants show signs of needing water (i.e. Wilted leaves), although I never leave them dry enough for the leaves to wilt.

The "lifting the pot to see if it is light" is a reasonably good method of telling when your plants need water but don't wait for the plant ot wilt ro show signs of dehydration. Brassias have pseudobulbs that store water and nutrients and by the time the plants starts to wilt it's already being stressed.

Originally Posted by holatombola

I use net pots so why is this fungus problem occurring, as I bought them specifically to allow some air circulation...

Net pots are not intended to prevent fungus or molds. Only a sterile environment can insure that. Just because you use net pots doesn't mean you'll be mold free - see comments about mold above.

Originally Posted by holatombola

Problem 2:

When I look at my orchids, they are all healthy as such to look at (i.e. No pests or damage, or signs of distress). However, the roots of almost all my orchids are dying. Well, I feel they're dying/dead because e.g. My Baby Phal's roots are green and living, and the plant is fine, but there seems to be a dead bit between the green root and the plant. So I am wondering how the plant is surviving. The Brassia's leaves are not green, at all really.

Do you think I should change potting medium? Could you suggest a better watering schedule?

Healthy roots are nto necessarily green. They can be whitish, creamish, or even brown. The best identifier is if they are firm and crisp.. If so then they are healthy. If they are mushy, grey/black or feel "empty" when you lightly squeeze them then they are dead. Don't go by colour alone. Different orchids can have roots that look different. Paph roots for example are thick and hairy like a tarantula's leg.

[BGGraham1]

Originally Posted by holatombola

I'm sure because the growth was not covering the entire piece of husk, there were individual protruding growths. I could clearly see the mushroom cap type shape, be it small. Perhaps a greyish green colour would be more accurate.

The dead bit is not velamen, as the whole root shrinks into the dead bit. The dead bit is shrivelled and brown in colour. To give you a picture, imagine the small healthy green root on the right, connected to the plant by a small 'dead bit' right on the base of the plant from which the root comes out. Hope that clears things up.

Maybe if you posted an actual picture, the more knowledgeable 'geeks can see what the dead bit looks like.

[Ray]

Actually hola-, your description of the shrunken-in part was great. And yes, that is collapsed root cells. That doesn't mean the root it necessarily "dead" though, as there is apparently enough connective tissue to keep the tip alive.

I'm going to go out on a limb here, and speculate that that sort of thing happens when the current conditions and existing root cells are incompatible.

When the root cells grow, they "tailor" themselves to the environment into which they are growing. After that, they cannot change. Alter the environment significantly enough - whether that be vastly different growing conditions, a new potting medium, or even potting medium that has aged - and those existing cells may not be very appropriate any longer, so may collapse with time. The new tips, however, ARE optimized for the current conditions, so are fine.

The potential risk is that the "collapsed" area in between the healthy root tips and the plant may continue to fade, ultimately separating the two.