Leaf Discolouration
 

Please would you help me, I am quite concerned about my Neofinetia falcata collection which I have grown without any problems. Recently I noticed this deep purple/black discoloration at the base of one plant, which I thought was normal, until it spread over the last few weeks to the underside of the leaves, then the second plant! The leaves of a Dendrobium Peguanum on the same shelf started turning a purple color, I moved that to a shadier area thinking it was too much light, although it has grown in the same place on my light table for 2 years! Nothing else has changed so I am puzzled and worried. Thank you inadvance for your help

Can you possibly post a picture? It would help a great deal.

leaf discoloration
 

Alice

Thank you for your quick response. Here are a couple of pictures of the plants. On the upper leaves I have noticed more speckles and lower leaves have turned very dark now.

Thanks for your help

Louise

Hi there,

I have leaves showing up on a plant or two that are variegated on half of a single leaf, dark healthy green on the other half. This is only showing up on some leaves of a plant, not all of them. And, some of the leaf tips curl radially, as opposed to up or down at the tips. I am using hydroponics and am wondering if I am missing some micro nutes, ie molybdenum? Any hydro experts out there ever see a problem like this???? The variegated parts almost look like some bad type of camo gear. Not yellow but light green with other parts of the same leaf perfectly green. Whazzup? The plants are doing great otherwise.

Promise of colorful blooms or magnesium deficiency??
 

I have several neo and crosses that have purple coloration, especially near the base of the fan, when they get very high light (which makes the blooms with color fabulously darker it seems). When they come in for display for a few weeks the color reverts to plain green. I keep them growing in morning sun where they will go purple but pull back when the purple turns to almost looking black.

Dr. Martin Motes, a wonderful vanda grower and general orchid expert, says that reddish pigment can be a sign of needed magnesium, remedied with a few doses of epsom salts (1 T/gal.) instead of fertilizer. All my orchids get regular doses of Epsom salts (magnesium sufate) nad potssium nitrate, so my purple is not a deficiency or a reaction to cold.

is it possible that it's black rot? It looks kind of the same thing from the "orchid basics" on the AOS homepage. I am a beginner myself so I really wouldn't have a clue, but just from what I have been reading all day, that looks like a possibility...:confused:

Both deffs are related to excess Ca. It seems your tap water is hard, with high Ca content. Mix it with distiled water. To check the soil ph, take a bit. Mix it with 2 parts of distilled water during 1-2h and then let it drain. Then use the drain again over the soil for 3-5 times, slowly and letting drain. The final water ph would be a good approximation of your soil ph.