Lime for Phrags?

[Shirley]

For some years now I've been giving my paphs a shot of dolomite lime three or four times per year and I'm wondering whether I should also be doing this with my phrags. Any opinions on this, please?

[Lagoon]

Shirley,

I would say No lime. The do much better with out of the calcium content and prefer RO water or even distilled. The phrag species like to have the pure water form, while the hybirds do a good job on adapting to higher calcium levels.
If you're phargs are getting too much calcium the tips will turn brown.

Phrags are not calcareous by nature like many of the paphs are.

[Shirley]

Thanks very much for the info, Gloria. I'll just carry on then as I've been doing and leave the lime for the paphs.

[derick242]

i heard cyps like lime too? or is this wrong?

[King_of_orchid_growing:)]

Originally Posted by derick242

i heard cyps like lime too? or is this wrong?

Most Chinese Cypripedium must have calcium supplements if you're not going to use limestone as part of the potting media, or substrate (if you're using raised beds).

In the wild, many of them come from forests with limestone bedrocks. The roots are only found in a thin layer of organic material. This is most likely why so many people complain about how Chinese Cyps are so damn hard to grow.

In fact, if your Paph originates from China, or if you have a hybrid that has a parent that originates from China, it's most likely going to need calcium. Maybe not all of them, but a good portion of them will. One example is Paph armeniacum, and Paph micranthum.

Some Phrags must also have calcium. I pulled up a search when Joe ("slipperfreak") had mentioned that Phrag fischeri was quite possibly a Phrag that grows on limestone, and that Phrag kovachii was also a Phrag that grows on limestone. Sure enough, at least Phrag kovachii had the type of rock it was growing on mentioned - and it's limestone. I believe that Phrag fischeri is also one of those that grows on limestone, as mine had a few problems even before I got it (in retrospect, I wasn't totally aware of how serious it would become). Eventually my inexperience and a lack of proper habitat information cost me my $50 plant!

[slipperfreak]

Okay, here's the deal:

Most Phrags like an acidic medium. There are THREE exceptions: fischeri, kovachii, and andreettae. These grow in a pH of up to 8.4. They will grow best if oyster shells or lime are added to the medium. They will also generally accept tap water. The vast majority of species and hybrids like a pH between 6 and 7 (sometimes down to 5.5), so you don't need to add anything to the medium, and pure water is best.

Some Cyps are calcicolous, and others are not. Most of the North American species should have an acidic soil (parviflorum, kentuckiense, acaule), though there are a few exceptions - montanum, reginae, and candidum. Some sources state that reginae likes acidic soil, but in fact it performs best if you add calcium to the soil, from lime or bone meal. Many of the Asian species like calcium, but not all. Most like a pH right around neutral - this applies to calceolus, farreri, fasciolatum, franchetii, and henryi. C. flavum likes a soil similar to reginae, but with more attention paid to good drainage. C. plectrochilum is also a calcicole. The remainder - tibeticum, macranthos, smithii, yunannense, debile, formosanum, japonicum, and probably micranthum will do best in slightly acidic conditions.

[King_of_orchid_growing:)]

Paph and Phrag datasheets:

slipperorchids.info

Holger Perner on Chinese Cyps:

encyp1.html

Cypripediums of Northern Sichuan (with photos)

[slipperfreak]

Great links Philip.

Anyone who is interested in growing Cyps should read Phillip Cribb's monograph on the genus, The Genus Cypripedium. This not only includes descriptions and habitat information on every species described up until 1997, but a comprehensive cultivation guide written by Holger Perner on each of these species. Holger Perner is one of the leading Cyp experts in the world, as is Phillip Cribb. This resource is so good, that any serious Cyp grower should at least read the book, if not own it. It's out of print, so hard to find and expensive, but well worth the investment. You will find better information in this book than in any web resource.