Help Dendrobium and Vanda yellowing :(

[kaarthiik]

Please help!
I am a new Orchid hobbyist, I seen these beautful plants recently. And ordered online after a tough research, I am with them for just 2 weeks and now I am worried. My dends and vandas are yellowing.

First week they were fine, I am from India and the week I recieved the plants, we did not have bright sun the temparatur was 50-55 F during day and 40-45 during nights. Humidity was 80% on average.

This week I had a very bright sun for 4 days, and today I was shoked to see the leaves yello . and few shedded ;(
When there was no sun, I water my dends once a week, but sprayed water on Vanda. On Sunny days, I am wated 2 times in 4 days (as pot was lite)

I did not repot/add fertilizer, Dends were placed on east side of my terrace, able to recieve bright sun.
Now I broght a big sheer to stop dirct light.
Pls help me how to take care...

Please see the pics attached

[prc11]

I would check the root system, I have saved more plants repotting them than not. If the roots are good I would guess too much light, but I doubt that was the problem.

[kaarthiik]

Originally Posted by prc11

I would check the root system, I have saved more plants repotting them than not. If the roots are good I would guess too much light, but I doubt that was the problem.

Thanks for quick reply! Root System are good I think, they are white, I can say. because I have taken very care not to make them stand in water, they are always dry.

[kaarthiik]

Originally Posted by kaarthiik

Thanks for quick reply! Root System are good I think, they are white, I can say. because I have taken very care not to make them stand in water, they are always dry.

Here are the pics of my root system, I am not sure what to do, In the morng, I watered dends and put some tea leaves (used tea leaves, I washed the used tea and dried over night) to act as fertilizer.
I am worried.

[CTB]

What type of potting mix are you using? Try using some commerical fertilizer at about half strength. I don't think tea leaves suit orchids. Your vanda should be watered till the roots turn green, when they turn white they need water. They should be watered at least once a day, what do you have your vanda potted in or is it bare root in a basket? Are your plants inside or out?

[kaarthiik]

Originally Posted by CTB

What type of potting mix are you using? Try using some commerical fertilizer at about half strength. I don't think tea leaves suit orchids. Your vanda should be watered till the roots turn green, when they turn white they need water. They should be watered at least once a day, what do you have your vanda potted in or is it bare root in a basket? Are your plants inside or out?

Thanks for your reply, The potting mix for the dends are bark (coconunt) and Vanda do not have any potting mix.

Please also suggest me weather, can removing flowers do any good to plant?

[King_of_orchid_growing:)]

There may be a combination of things going on here, not just one thing.

CHC (coconut husk chips) is what your Dendrobium is growing in. It retains quite a bit of moisture for quite a few days. That's something to consider.

It looks as if the potting media does need to be replaced. If you like the flowers, just cut the stem off with a pair of sterilized cutters or scissors and put them in a vase. You can use isopropyl alcohol or run the cutters over a flame for about 30 seconds to 1 min. Removing the flowers may help the plant out in this situation as well.

The other thing is, you say the roots on your Den are white...

Do they turn green when you water them?

Do any of them have fleshy green tips?

The temperatures you mentioned are very low for these types of orchids. They prefer to be warmer.

Preferably the winters should be in the range of 55 F to 75 F (13 C to 24 C) for your Dendrobium.

For your Vanda, the low end should ideally be around 60 F (16 C).

The sun's rays even on a cloudy day can still be very strong. Light coming from the sun is much more than just the visible light spectrum everybody sees. These rays are passing through the clouds and still providing a source of radiation. You may want to make sure that the light the plants are receiving are not excessive. Perhaps if you were able to get a hold of a light meter, this will be much more apparent.

For the Vanda, as long as it's very bright indirect light, it should be fine. Even for something like this, they cannot tolerate direct sun light.

The Dendrobium needs indirect moderate light. No direct sunlight at all.

Maybe rice water would be a better fertilizer. I'm not familiar with tea as a fertilizer.

[kaarthiik]

Originally Posted by King_of_orchid_growing:)

There may be a combination of things going on here, not just one thing.

CHC (coconut husk chips) is what your Dendrobium is growing in. It retains quite a bit of moisture for quite a few days. That's something to consider.

It looks as if the potting media does need to be replaced. If you like the flowers, just cut the stem off with a pair of sterilized cutters or scissors and put them in a vase. You can use isopropyl alcohol or run the cutters over a flame for about 30 seconds to 1 min. Removing the flowers may help the plant out in this situation as well.

The other thing is, you say the roots on your Den are white...

Do they turn green when you water them?

Do any of them have fleshy green tips?

The temperatures you mentioned are very low for these types of orchids. They prefer to be warmer.

Preferably the winters should be in the range of 55 F to 75 F (13 C to 24 C) for your Dendrobium.

For your Vanda, the low end should ideally be around 60 F (16 C).

The sun's rays even on a cloudy day can still be very strong. Light coming from the sun is much more than just the visible light spectrum everybody sees. These rays are passing through the clouds and still providing a source of radiation. You may want to make sure that the light the plants are receiving are not excessive. Perhaps if you were able to get a hold of a light meter, this will be much more apparent.

For the Vanda, as long as it's very bright indirect light, it should be fine. Even for something like this, they cannot tolerate direct sun light.

The Dendrobium needs indirect moderate light. No direct sunlight at all.

Maybe rice water would be a better fertilizer. I'm not familiar with tea as a fertilizer.

Thanks! King for your reply.
I have never seen hanging roots of Den turn green. And I was reading not to give lots of water, so I never made Den's root to stay in water for a more time. I use to pour water on bark until the water run out from them. And I make them dry to natural air.

I observed very few root tips were green and fleshy, and roots that were stick to bark are turning green when watered with more amount.

I am watering Vanda roots via sprayer until they become light green (after watering for 2 times they are turning green)

Thanks for suggesting me use rice water, correct me if I am wrong, Water used second time for washing acts as fertilizer or the first time water (I heard that people are using chemicals for whitening rice) I used tea by reading a thread, i thot of using rice water next time.

Its hard for me to get professional orchid mix in India for re-potting, is there any way to make the potting media self? And now temparature here is around 55 F during day. hope this is good now.

Thanks for your suggestions... And pls suggest me more..

[drone]

I think the leaves got sunburned. I had a dendro which become bald look like this. I dont know how you're going to free the roots from coconut though. They usually grow all tangled up.

You can make your own media mix from chunks of charcoal/broken bricks/coconut/styrofoam. You make it wetter or drier depending on your growing area and how often u want to water. I'm still at the trial & error stage to what's good for my place.

Here's an example to pot with coconut and styro. This is just to give an idea.
Potting orchids using coco husk medium

how to make chcs
Coconut husk chips : your guide to CHCs

[kaarthiik]

Originally Posted by drone

I think the leaves got sunburned. I had a dendro which become bald look like this. I dont know how you're going to free the roots from coconut though. They usually grow all tangled up.

You can make your own media mix from chunks of charcoal/broken bricks/coconut/styrofoam. You make it wetter or drier depending on your growing area and how often u want to water. I'm still at the trial & error stage to what's good for my place.

Here's an example to pot with coconut and styro. This is just to give an idea.
Potting orchids using coco husk medium

how to make chcs
Coconut husk chips : your guide to CHCs

Drone, Thanks for reply, Please share how you have saved your dend?