Greenhouse shade advice needed.

[Shadeflower]

Nother test subject. Newest growth has red leaves when this variety should not produce red leaves.

Not caused by high light.

Worth investigating.

[Roberta]

Originally Posted by Shadeflower

Nother test subject. Newest growth has red leaves when this variety should not produce red leaves.

Not caused by high light.

Worth investigating.

It's name?

[isurus79]

Originally Posted by Shadeflower

Nother test subject. Newest growth has red leaves when this variety should not produce red leaves.

Not caused by high light.

Worth investigating.

What's the name on this one?

New growths often have redder leaves than the adults, which turn green as the growths mature. Again, its a natural sunscreen and generally not a nutrient deficiency. I'm not saying there's no possibility of nutrient deficiency, but Occam's Razor says the simplest solution is typically the correct one. Red leaves on orchids (especially new growths!) is a very common defense mechanism to protect from sunlight.

[Shadeflower]

Originally Posted by Roberta

It's name?

Roberta, I just had a look at the list of your plants.

You have soo many on my wishlist!!

I really want to see your Dendrobium Brymerianum and falcorostrum if you have them flowering someday.

You have so many cymbidiums and Laelia's. I just scrolled through the laelia list, except for the harpophylla all outdoors.

So I take it you like laelia's.. The one above it a laelia. It might be presumptuous of me - I don't know how many laelia's are quite big but can you guess which laelia it is.

You have this one.

ok might be too presumptious so a clue it starts with an X

[Roberta]

Thanks! Den brymerianaum didn't survive, alas.. I have heard from others that it is tricky. I tried a couple of times, bloomed once or twice so I got my pix, then lost. Den falcorostrum is easy where I live. Alas, international shipping/permits very nasty, though. The trick on that one seems to be chilly nights. Fred Clarke mentioned in one of his talks that he had it in the GH, it got very large but nary a flower... he finally got disgusted, told it sink or swim, put it outside, and it bloomed beautifully. So classic Aussie Den culture. I don't think it so much the "dry" (I don't bother to dry them out) but rather the cool nights.

All of the Mexican Laelias (still considered Laelia) like anceps, autumnalis, gouldiana have the potential to get fairly large. I love them because they are tough as nails - temperature range somewhere between -3 C and 40 C (28 deg F to over 100 deg F) and drought-tolerant. Of the Brazilian Laelias (now Cattleya) consider looking for L (C) jongheana - huge flowers for the size of the plant which is quite compact.. It's one of those where the buds emerge from the new leaves without going through the "sheath" stage. But what's not to love about a 6 inch (15 cm) flower on a plant that is the same height or maybe smaller.

In short, I mostly love the ones that I can grow outside (cold tolerant) - GH is tiny, stuffed, and not getting any bigger. In the yard, there's always room for one more... Cyms are the easiest of all where I live - one of the best climates in the world for Cyms. To the point that they don't get enough respect. Also very easy for me to get-several major Cym growers with nurseries within an hour or two drive, they often supply society raffle tables, auctions, etc.

I know that getting these plants in the UK has been somewhere between difficult and impossible. But shows are starting up in the next few months. (I subscribe to Orchid Review so I'm on the RHS email list and have seen notices for Chelsea Flower Show) International vendors from the EU and South America may not want to deal with small individual orders, but for shows they do large imports. I strongly suspect that they operate somewhat like they do in the US - when they come for a show, they will ship plants that are pre-ordered, once they get inside the country. Shadeflower, if you are not a member of the RHS you should be... Orchid Review is a terrific magazine, and also you'll find out about shows.

[K-Sci]

Originally Posted by Shadeflower

Nother test subject. Newest growth has red leaves when this variety should not produce red leaves.

Not caused by high light.

Worth investigating.

I'm confused by your worry concerning red leaves. I see them as a good sign; an indication that I'm providing adequate light levels. See the Cattleya 'Heaven's Gate' in the attached photo. I have thriving C. dowiana seedlings where the leaf is red where it emerges and the red fades as the leaf ages.

I have seen red develop in response to water temperature shock (water in a hose heated by sun).


-Keith

[Shadeflower]

thanks keith, not so much a concern at the moment.

Yours looks nice and healthy.

It's not just reddening I am investigating.

I am investigating

1) leaf yellowing when flowering (energy being sucked from leaf)
2) reddening

I want to see if I can reduce the leaf yellowing and what the red leaves mean.

So out of my 300 + plants I am doing this because of this one annoying Dendrobium Jenkinsii I pictures before.

It has a problem, there is no doubt about it. It was caused by incrteasing light but this change also caused it to start producing an insane amount of new growth so I don't believe the light is a problem, maybe there is no problem but I do not like stunted growth so it is bugging me.

The one in a million sort of buggyness so you are probably right but I will not be able to leave it without making some tests.

I also just found out that another grower that bought an identical vanda at the same time as me from the same place just got hers to flower! Mine is not! Mine has red leaves! So that bugs me also. And it's too early to tell but I think I have managed to reduce the red on that vanda already within just a few days but it is too early still. How would you feel if that happened to you Her Vanda was n worse shape than mine too! I know it could be pure coincidence or this grower has done better than me this year and erm that just isn't on tbh

[isurus79]

I’ve never heard of increasing blooms with lower light and I’ve never heard of yellowing leaves occurring during flowering because the plant is sucking energy from the leaves and sending them to the blooms. I don’t think that’s how their biology works. Can you provide links for where you’re getting this information from?

[Shadeflower]

Orchids regularly drop a leaf when they flower. If there is any time in the year an orchid decides to shed an old leaf it is most likely to occur when the orchid flowers. This is why some nutrients are called mobile elements and others are immobile elements. Mobile elements get relocated from one part of the plant to another as they are needed.

I just posted a video about fertilizing oncidiums in the S/H thread - it gets explained in that one

Although the video explains this in good detail this was nothing new to me.

I've currently got 3 orchids doing it. As they flower they drop their oldest leaf and next year the same will happen.

Like keith says it might all be completely normal but to rub salt into the wounds

another growr just told me that only bad growers get thrips in their collection

[isurus79]

Originally Posted by Shadeflower

Orchids regularly drop a leaf when they flower. If there is any time in the year an orchid decides to shed an old leaf it is most likely to occur when the orchid flowers.

In the roughly 30 years I've grow orchids, I've never heard of such a thing, nor have I experienced such a thing!

Originally Posted by Shadeflower

another growr just told me that only bad growers get thrips in their collection

I think you should stop talking to that grower! lol