I had a bitch of a time trying to find this information on the web, but this post on SlipperTalk is what got the ball rolling (so thank you to the countless people who share their experience). I will update this page if I change my mix.
My Preferred Current Mix
‘The Best Paphiopedilum Potting Medium’
(btw, this ‘best mix’ is according to nobody else but me)
- Orchiata Bark – 50%
- Perlite – 15%
- Pumice – 15%
*Full-Range Sizes (from sand to large) - Charcoal – 15%
- Canadian Peat Moss – 5% (optional, for longer water retention if the media is drying out faster than a week)
- Sphagnum Moss
*Used as a top-dressing to hold humidity in to the root zone and to double as a “water now” tip when the sphagnum is crispy-dry - Gia Green Rock Dust
- PalmGain Palm Fertilizer
Prepping the Paph Substrate
I wash each material and then mix the hard compounds together (bark, perlite, pumic, and charcoal). Next, I’ll add a light dusting of the rock dust to the top, as well as a light sprinkle of the palmgain fertilizer and mix it all in to the medium.
Potting the Paphiopedilum in the New Medium
I’ll put extra charcoal in the bottom of the pot to suck up any junk if the water happens to sit at the end of a watering. Next I’ll put a small layer of the medium. Next I’ll fish out 3-5 long strands of sphagnum moss and dangle them into the pot so they’re spaced evenly around the edge of the pot with the length dangling into the middle and the other half hitched at the top, or hanging out (i want these strands to hold water a little longer in the substrate). I’ll put the roots of the plant in and then fill with the remaining potting mix. I’ll use a chop stick to push any extra medium into the air gaps around the sides. I’ll finish of by placing a layer of spahgnum moss on the top of the potting mix. I don’t want it too thick, but thick enough that I can’t see the substrate underneath, and I want the paph to be sunk into the moss. The objective here is to create a humid barrier around the base of the plant so that new roots have a fighting chance in my low-humid house.
I will water when dry, and often will allow the plant (and pot) to soak in a bowl/cup of water for an hour or more.
Other Great Paphiopedilum Substrate Mixes I’ve Found Throughout my Search
1. Lechuza-Pon Substrate Potting Mix (also used for orchids and phaphiopedilums)
Sold with Lechuza Pots used by OrchidMan UK
Zeolite, German washed pumice, German light Lava (supplies your plant with iron permanently), Fully coated premium quality fertilizer (the coating is purely organic and degrades residue-free – the fertilizer supplies your plant with nutrients for up to 6 months).
Suitable for all plants, like foliage and flowering plants, orchids, citrus plants, herbs, tomatoes, fruit trees and cacti!
2. Paphman91 Paphiopedilum Medium
I grow all my multifloral with fine bark, perlite #4, sphagnum mixture of the top five inch of the pot. I use lava rock, perlite and gravel stone for the bottom half of the pot to provide good drainage. They grow real fast but I repot them 1 to 1.5 year.
I also have a Paph phillipinense that has been growing the the same pot for three years in a mixture of sponge rock #4 and sphagnum moss. The plant produced five flowers on its first blooming with two new growths.
3. Terry’s Paphipedilum Substrate from Pine Ridge
The “template” rock wool mix is laying on top of large sponge rock (perlite) in the first step for making our final orchid potting mix. Next we add several other media components like shredded rubber tires and coir (coconut husk dust). Water holding polymers are added to the mix which will absorb about 400 times it’s own weight in reserve water. The roots of the plants will absorb water out of the polymer gel even if the media goes a bit dry. A certain percentage of long fiber sphagnum moss is added depending upon the genera being potted up. Expanded slate is added to the mix. The slate has been expanded in a 2000 degree tunnel kiln to make it light weight. It’s pH is 7.0 (neutral) and extremely stable. This is the final mix that we would use for the multi-floral Paphiopedilums and the Catasetinae.
Terry Glancy of Pine Ridge Orchids uses a mixture of hydrophilic and hydrophobic rock wool with Aliflor (leca), perlite, aerolite(styrofoam balls), coir (coconut fibre) and a little bit of bark (more for paphs) mixed in to break up the rock wool and let it crumble easily. He has also used AgroDiamonds that hold water (purchase from RA/AG Enterprises – 10104 150th Ct. N., Jupiter, FL 33478 — (888) 729-2476).
4. Eric Muehlbauer’s Paphiopedilum Potting Mix
I use small CHC chips, augmented by major amounts of dynarok (= diatomite?), lava rock, leca, spongerock, and charcoal. I used to rely on spongerock alone, but I haven’t been able to find it in the right size. Although CHC takes longer to break down than bark, it gets majorly waterlogged over time, so over the years I’ve increased the inorganic portion of the mix. I still repot after its been in the mix a year…and add extra for brachys, which stay a bit longer, because they seem to really resent repotting, even though they love fresh airy mix. The exceptions are delanatii, which gets a phrag mix with fine bark and NZ sphagnum in addition to the inorganics, and small seedlings…simply because fine bark is smaller in size than fine CHC…Take care, Eric
Paphiopedilum Mixes and Substrates – Other Online Links