Darkening up leaves

[AdamD]

So a few of my paphs are getting very light green, gradually, over the past few months. It's nothing alarming, they are growing leaves and roots just fine, new growths, the works. It just seems the newest leaves are darker, healthier looking, and the old ones are losing their luster. I mainly grow multis, and lately the older leaves look "vein-like," for lack of a better term. This is not like Naoki's problem (bleaching), the leaves are just veined darker over more washed out looking base color.

I use K-lite at about 40-50 ppm N at (almost) every watering, RO water (changed filter recently), 60 - 80% humidity, temps 60 - 82 F. Also use foliar (urea) spray every two weeks or so. This really helped darken them up at first, now not so much. Lately the sun has been beaming in more through the window in addition to the HPS lights.

So, too much light maybe? Not enough Ca? Hard to believe with K Lite... Not enough Mg? Macros? Any advice would be appreciated. Thanks

 

[Stone]

So a few of my paphs are getting very light green, gradually, over the past few months. It's nothing alarming, they are growing leaves and roots just fine, new growths, the works. It just seems the newest leaves are darker, healthier looking, and the old ones are losing their luster. I mainly grow multis, and lately the older leaves look "vein-like," for lack of a better term. This is not like Naoki's problem (bleaching), the leaves are just veined darker over more washed out looking base color.

I use K-lite at about 40-50 ppm N at (almost) every watering, RO water (changed filter recently), 60 - 80% humidity, temps 60 - 82 F. Also use foliar (urea) spray every two weeks or so. This really helped darken them up at first, now not so much. Lately the sun has been beaming in more through the window in addition to the HPS lights.

So, too much light maybe? Not enough Ca? Hard to believe with K Lite... Not enough Mg? Macros? Any advice would be appreciated. Thanks

Could be low in sulphur and or mangesium (try spraying with Mag sulphate but don't expect fast results) Light could also be a factor. All my plants are paler now (especially the older leaves) Its very bright now. Spraying has helped but slowly and unevenly. It is really not at all easy to bring back chlorophyll to older orchid leaves! (Unless someone can tell me how?)

 

[ehanes7612]

probably because of more light, it can happen fairly quickly, i wouldn't worry about it though..water them a little more

 

[gonewild]

Are you sure that the lighter green leaves are not actually the correct color for a healthy plant?

 

[polyantha]

It is really not at all easy to bring back chlorophyll to older orchid leaves! (Unless someone can tell me how?)

You can change to a fertilizer with urea as N source. Within half a year you should get good results. After this time I stopped using urea and didn't use fertilizer at all to get new roots starting. Urea generally slows down root growth or stops it completely, but it is good to produce new growths and high chlorophyll in the leaves. After the urea period it is a good idea to repot the plant and get fresh bark. No fertilizer for two months after repotting.

 

[polyantha]

This is P.philippinense. I received the plant with yellowish leaves. 1/2 year of urea and the plant was green again. Now it has a completely normal color even without urea.

 

[AdamD]

Polyantha, when you watered with urea did you soak the leaves?

 

[Justin]

my results are.the same as polyantha's. i use 30-10-10 and k lite intermittently. also from what you are describing it might be the light levels. for your HPS.you could.cut back an hour.off the timer.

to lance's point though, when you see roth in situ pics they are usually the color of a granny smith apple.

 

[AdamD]

I'll post pics this weekend when I have time to sit down at the computer. I'll try switching up the fert regiment if it gets worse. Thanks for the replies

 

[AdamD]

Are you sure that the lighter green leaves are not actually the correct color for a healthy plant?

Well my LI has been in sheath for a month now (getting impatient). Maybe flower count/ stem substance will tell me more? Your question is one I've been asking myself. Maybe I'm comparing too much.

 

[gonewild]

Well my LI has been in sheath for a month now (getting impatient). Maybe flower count/ stem substance will tell me more? Your question is one I've been asking myself. Maybe I'm comparing too much.

The thing to remember is.... You might want the leaves to be dark green because that color pleases you more from a beauty standpoint. But that does not mean that the pale leaves indicate a healthy growth problem.

 

[Happypaphy7]

True.
Many wild collected Paph. phillippinense were reported to have yellowish leaves due to exposure to adequate amount of light in their habitat.