And. Murasakikomachi (Zns. Roquebrune x Agn. cyanea)

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Alan Koch of Gold Country Orchids talked about Zygo spotting to our club a while back. He said the problem is caused by salt uptake. He said you can prevent it by taking steps to minimize salt uptake to and deposition in the plants: Keep them always moist with very pure water; grow in loose sphagnum; flush [25 minutes or so] after each watering [especially after fertilizing] with pure water; and keep night temperatures under about 71 F/21C.

This part is near the very top of my lecture notes from that evening. You can find them using the Advanced Search function above. Search on terms "DVOS Koch" and my partial username estaci. Or if that's too much work:

Alan Koch, Gold Country Orchids, DVOS 2017 02 16

[WaterWitchin]

I’m not understanding. If you use RO water, why would you need to flush... and for 25 minutes with pure water?!? I must be missing something.

---------- Post added at 02:41 PM ---------- Previous post was at 02:39 PM ----------

PS I can understand flushing after fertilizing if they are salt intolerant. But not when just watering with pure water.

[Clawhammer]

Originally Posted by WaterWitchin

I’m not understanding. If you use RO water, why would you need to flush... and for 25 minutes with pure water?!? I must be missing something.

The direction was to flush 25 min after watering, especially when fertilizing to prevent salt build up

[WaterWitchin]

Okay, misread. Gracias Clawhammer... that answers part of it. Twenty-five minutes of flushing seemed a tad excessive.

But why flush if not using fertilizer? That part I still don't get.

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A lot of people use tap water for orchids. Alan said he uses well water most of the time, then flushes with a little RO to save money. Of course he has several hundred thousand orchids.

He told us orchids take up essentially all the fertilizer they can hold within the first 25 minutes, so fertilize when the roots are driest, then flush sensitive plants with RO or rain.

[Dollythehun]

So, I'm guessing you shouldn't use time release.

[Clawhammer]

Originally Posted by Dollythehun

So, I'm guessing you shouldn't use time release.

I think s/h culture would be challenging as well.

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Based on what Alan said, I wouldn't use time release fertilizers on this kind of plant.

Ray recommends fertilizer of around 10 ppm nitrogen with each watering for S/H, which is quite low. Applying Alan's recommendation, water the S/H Zygo with your fertilizer solution, then 25-30 minutes later flush it with pure water. But this is only speculation.

I have grown Pescatorea and hybrids in S/H. They loved it.

[WaterWitchin]

Okay, I get it. Must have been pulling carpet tacks for too long yesterday. Not necessary if using RO water to flush. Only follow up with RO water flush 25 or so minutes after fertilizing.

I use RO water in winter. In summer I have a small group that still gets RO, and a large group that gets rain mixed with pond water. Need to move my few Zygos over to the RO only group. Good info for me. I avoid Zygos anymore, as I don't like the ratty foliage. May try again.

Gracias ES for the info, and Gracias Clawhammer for getting understanding pounded into my thick skull!

---------- Post added at 07:51 AM ---------- Previous post was at 07:46 AM ----------

Originally Posted by Clawhammer

I think s/h culture would be challenging as well.

Mine grow fine in semi-hydro, other than getting speckly leaves. I think the salt-sensitive part is the key to my mystery. I have a Den species (can't remember what) that also does that. I'll bet it's the same thing... salt sensitivity.

[DirtyCoconuts]

Originally Posted by WaterWitchin

Okay, I get it. Must have been pulling carpet tacks for too long yesterday. Not necessary if using RO water to flush. Only follow up with RO water flush 25 or so minutes after fertilizing.

I use RO water in winter. In summer I have a small group that still gets RO, and a large group that gets rain mixed with pond water. Need to move my few Zygos over to the RO only group. Good info for me. I avoid Zygos anymore, as I don't like the ratty foliage. May try again.

I agree. Bit of you do decide to give up....send me my way. I like em. Ratty don’t bother me