Questions about sphagnum moss as a medium

[HiOrcDen]

I am curious regarding a few things about using high quality sphagnum moss as a substrate for orchids.

First off, why not use sphagnum exclusively as a substrate, so that one doesn't need to water as often? I imagine it would be that Orchids grow faster in a faster growing bark or similar mix, is this correct?

How do you pot an orchid with moss? Do you shred the moss into pieces, or into thin layers, and arrange the roots?

Finally, some of the plants I've purchased have moss towards the top of the mix, and a bark mix for the rest. So why is this done?

Oh almost forgot... Is it very important to use New Zealand sphagnum moss? I have 'Super Moss' which is supposed to be high quality, but is not specified as New Zealand.

[Ray]

Sphagnum can-, and is used as an orchid potting medium. Just about every imported phalaenopsis is in it, and that’s the majority of plants you can acquire.

It is somewhat of an enigmatic potting medium though. It can be used somewhat loose or tightly compacted, and depending upon your conditions and watering habits, one might be better that the other.

With loosely packed sphagnum (my preference when using it), over time it will become more and more compacted and broken down, which can suffocate roots. When I relocated my plants from a greenhouse in PA to windowsills/outdoors in NC, I moved all my phals into sphagnum. However, I found that it degraded far too rapidly, requiring me to replace it about every 6 months. (I now use 100% inorganic media, avoiding that altogether.)

For me, long-strand sphagnum is better, as it remains more springy and “open” that do shorter-strand or chopped moss. Different sphagnum species have different characteristics. Those originating (and farmed) in NZ are preferred, but not absolutely necessary.

Take a look at THIS.

In a couple of posts, you have inquired about particular potting media ingredients, but they are not really what’s important. Focus first on understanding the “air/water ratio” that your specific plants prefer at their roots, then consider how the various potting media components can help you achieve that in your growing conditions.

There are seemingly infinite ways to “skin that cat”, so you need to consider what’s best for you.

[tmoney]

howdy,

so i can tell you why we didn’t start using moss and learning with it right away, and that’s cause, as ray mentioned, pretty much all of our purchased plants came in it, and that stuff was rank when the plants got repotted. so it turned me off, and my gut said it wasn’t how i wanted to grow my plants. after researching, we learned about what other peeps do and modeled our media mix on that.

but, after these couple short years we r rethinking the aversion to moss, and have actually just done our first phal completely in tight packed sphag. mostly this is to reduce our water consumption if we can figure out how to make it work. as expected, tightly packing the moss means we used a whole lot more than we usually do, and that is a factor we r adding in. moss is expensive, and bark mixes, at least according to my math, can be done cheaper. now, weigh 8n the cost of water savings and it’s probly a wash.

but, as ray said, lots of folks grow successfuly exclusively in moss, like big nurseries. just gotta figure out the watering

[Roberta]

As Ray pointed out, first figure out the environment that you want for the plant, then look at the ways that you might achieve it. For instance, I use sphagnum a lot for my outdoor plants in baskets, loosely packed. They get very wet, but then dry out. Even when the long-fiber sphag partly disintegrates, those fibers create a very airy environment. But that's in baskets, on my patio, with lots of watering. And lots of (rather dry) air. Tightly packed in a plastic pot in the house, one gets a very different effect. And needs a different approach to watering frequency.

[estación seca]

Phals in Taiwan are grown in tightly packed sphagnum in carefully temperature controlled greenhouses. It works well for warm growing orchids like Phals only when they are kept warm. Warm means 70 F / 21C minimum at night, preferably higher, and 80s to 90s F / 26-38C during the day. They are cooled to induce flowering.

Evaporative cooling of sphagnum will lower container temperature and cause trouble for warm growing orchids during cool weather.

Sphagnum is good for cooler growing orchids in spaces warmer than ideal. The evaporative cooling helps cool the roots.

If you're growing outside in southern California, your winter temperatures are far too low for Phals anyway. But unless you want to keep your indoor growing area very warm, I wouldn't grow Phals, Cattleyas nor warm-growing Dendrobiums in sphagnum in your situation. It would be fine for cool to intermediate growing orchids.

[HiOrcDen]

Originally Posted by Ray

Sphagnum can-, and is used as an orchid potting medium. Just about every imported phalaenopsis is in it, and that’s the majority of plants you can acquire.

It is somewhat of an enigmatic potting medium though. It can be used somewhat loose or tightly compacted, and depending upon your conditions and watering habits, one might be better that the other.

With loosely packed sphagnum (my preference when using it), over time it will become more and more compacted and broken down, which can suffocate roots. When I relocated my plants from a greenhouse in PA to windowsills/outdoors in NC, I moved all my phals into sphagnum. However, I found that it degraded far too rapidly, requiring me to replace it about every 6 months. (I now use 100% inorganic media, avoiding that altogether.)

For me, long-strand sphagnum is better, as it remains more springy and “open” that do shorter-strand or chopped moss. Different sphagnum species have different characteristics. Those originating (and farmed) in NZ are preferred, but not absolutely necessary.

Take a look at THIS.

In a couple of posts, you have inquired about particular potting media ingredients, but they are not really what’s important. Focus first on understanding the “air/water ratio” that your specific plants prefer at their roots, then consider how the various potting media components can help you achieve that in your growing conditions.

There are seemingly infinite ways to “skin that cat”, so you need to consider what’s best for you.

Hmm I am very curious... what is in your totally inorganic mix for Orchids!

Thanks for the link! I am studying it. Well I am a hobbyist, so I only have 3 Phals amongst my 30 or so Orchids. Plus I recently ordered a bunch more for a Christmas gift to myself! Haha... Oh by the way, I should finally mention that my name is Ray as well! Hopefully 2nd Ray on the forum lol... though 3rd would be okay, as 3 is a lucky number for me! DX

Originally Posted by tmoney

howdy,

so i can tell you why we didn’t start using moss and learning with it right away, and that’s cause, as ray mentioned, pretty much all of our purchased plants came in it, and that stuff was rank when the plants got repotted. so it turned me off, and my gut said it wasn’t how i wanted to grow my plants. after researching, we learned about what other peeps do and modeled our media mix on that.

but, after these couple short years we r rethinking the aversion to moss, and have actually just done our first phal completely in tight packed sphag. mostly this is to reduce our water consumption if we can figure out how to make it work. as expected, tightly packing the moss means we used a whole lot more than we usually do, and that is a factor we r adding in. moss is expensive, and bark mixes, at least according to my math, can be done cheaper. now, weigh 8n the cost of water savings and it’s probly a wash.

but, as ray said, lots of folks grow successfuly exclusively in moss, like big nurseries. just gotta figure out the watering

Hey there! Thanks for the advice. So I am wondering, from a standpoint of time efficiency, all else being equal, why not use moss, simply so you don't have to water as often? Do the plants grow faster in a bark or other similar mixture, including an inorganic one as Ray mentioned?

Originally Posted by Roberta

As Ray pointed out, first figure out the environment that you want for the plant, then look at the ways that you might achieve it. For instance, I use sphagnum a lot for my outdoor plants in baskets, loosely packed. They get very wet, but then dry out. Even when the long-fiber sphag partly disintegrates, those fibers create a very airy environment. But that's in baskets, on my patio, with lots of watering. And lots of (rather dry) air. Tightly packed in a plastic pot in the house, one gets a very different effect. And needs a different approach to watering frequency.

Hi again! Thank you for this. So with baskets, that refers to hanging pots, right? The great majority of my Orchids are outside now, and soon I will have to employ some hanging baskets. On that note, would you guys recommend a good cost effective place to buy hanging baskets?

Originally Posted by estación seca

Phals in Taiwan are grown in tightly packed sphagnum in carefully temperature controlled greenhouses. It works well for warm growing orchids like Phals only when they are kept warm. Warm means 70 F / 21C minimum at night, preferably higher, and 80s to 90s F / 26-38C during the day. They are cooled to induce flowering.

Evaporative cooling of sphagnum will lower container temperature and cause trouble for warm growing orchids during cool weather.

Sphagnum is good for cooler growing orchids in spaces warmer than ideal. The evaporative cooling helps cool the roots.

If you're growing outside in southern California, your winter temperatures are far too low for Phals anyway. But unless you want to keep your indoor growing area very warm, I wouldn't grow Phals, Cattleyas nor warm-growing Dendrobiums in sphagnum in your situation. It would be fine for cool to intermediate growing orchids.

Thank you so much, once again for the guidance. Interestingly, I have had a Phal outside, still perfectly healthy, and the temps have dropped to 41f. It is a 'Novelty/Fragrant' though, if that makes a difference??

So I am very curious, what kind of inorganic mix would you employ with Orchids?

[estación seca]

I use LECA for many orchids, both for S/H and regular potting. Large chunks of pumice work well but it's not much available.

[Roberta]

As far as Phals growing outside in southern California, I certainly agree that it's a lot colder than they like. But I do know people who get away with it - usually with fairly large plants, in a sheltered area. Against the house or a block wall, there can be radiated warmth that gives adjacent plants a few extra degrees, and sometimes that's enough. (I never say "Never", since I am a "What can I get away with?" grower) Of course natural selection takes care of the ones where it really is too cold.