Paphiopedilum rothschildianum

[Ray]

Originally Posted by Optimist

We have really hard water here lots of calcium, but I will try the cal-mag in RO. Thanks.

Or just switch to a fertilizer containing it - K-Lite has the most @ 10%, followed by the MSU RO formula @ 8%, the Peters Excel Cal-Mag @ 5%.

[Theodoreorchidking]

What media are they in and when do you water?

[Ray]

Originally Posted by Theodoreorchidking

What media are they in and when do you water?

This particular plant is in a mix of 67% LECA & 33% rockwool mini-cubes.

[Optimist]

Just got my Rothschildianum from Normans, and was slightly disappointed. It's 6 years old, so called "premium" and yet only one growth and no sign of anything else potentially coming up. Maybe it's sour grapes, but the cheaper one I got through Mike, who you know, seemed healthier. I had to get on him because of his slack mailing/packaging. Still. Now I got to wait two years. Sad. This summer will tell. I think i am going to put them outside a lot. Some of my orchids spend a lot of time outside, as long as it is not too hot. It really inspires them to grow. (Natural sun is worlds different from grow lights).

[Optimist]

Originally Posted by Roberta

if water is higher in TDS than that, maybe dilute it with RO. But I'd suggest saving your RO for plants that really want and need it (like the Phrags and the various cloud forest groups). Cyms and Catts also don't seem to care.

Thanks, Roberta, this is a great tip.

---------- Post added at 08:26 AM ---------- Previous post was at 08:24 AM ----------

Originally Posted by Ray

Or just switch to a fertilizer containing it - K-Lite has the most @ 10%, followed by the MSU RO formula @ 8%, the Peters Excel Cal-Mag @ 5%.

Oh, that's right. I use K-Lite anyway.

---------- Post added at 08:41 AM ---------- Previous post was at 08:26 AM ----------

Originally Posted by Lil Duck

Mottled leaved Paphs tend to grow in limestone cliffs and may do better with some marble mixed into the potting media or with some extra CalMag incorporated into the fertilizer regime.

I use K-Lite with the Cal-Mag. Also various of the paphs do grow in limestone cliffs. Paph Rothschidianum grows naturally on the slopes of Mt. Kinabalu, in Serpentine which is Granite. Does this matter? One paph grower I have listened to (Here But Not blog) uses a rock dust supplement called Gaia Green in both his phrags and paphs.

[estación seca]

Plants grow where they grow not because they prefer those conditions but because they can outcompete other plants in those conditions. Serpentine contains levels of various metals toxic to many plants. That doesn't mean serpentine natives need those metals.

[Ray]

Originally Posted by Optimist

I use K-Lite with the Cal-Mag.

K-Lite, by itself has plenty of calcium and magnesium. Overdoing it might be detrimental to the plants.

Nitrogen, potassium, calcium and magnesium can be antagonistic - too much of one or more can interfere with the uptake of the others. The synergistic/antagonistic relationships were put into "Mulder's Chart"

[Jmoney]

Originally Posted by Lil Duck

Mottled leaved Paphs tend to grow in limestone cliffs and may do better with some marble mixed into the potting media or with some extra CalMag incorporated into the fertilizer regime.

from what I remember most of the mottled leaf "Maudiae type" species do not actually grow on limestone. I may be wrong but I still remember Antec's article from years ago regarding which plants seem to have a closer association with limestone (and hence might benefit from oyster shell from us growers). I think almost all brachys, parvis (except delenatii), and most multifloral species. I still refer to that when repotting. if anyone has updated info would love to hear!

[Ray]

I urge everyone to look into the water solubility of all of those minerals, shells, etc., before relying upon them as calcium sources.

[estación seca]

I'll state it more boldly: Oyster and egg shells in potting media provide essentially no additional calcium unless pH is far lower than healthy for most plants. Put your oyster shells in the attic with your humidity trays.