Loosely vs. Tightly Packed Sphagnum Moss

[netrizone]

Hi all, I'm repotting some phals right now, and I've seen conflicting opinions on whether to pack the moss loosely or tight.

A lot of videos online recommend keeping the moss loose and fluffy to maintain air pockets and to not suffocate roots. However, I've heard others say that tight moss distributes water more uniformly.

Also, my phals were (presumably) imported from Taiwan, and they seem to be thriving in their tightly packed moss medium with brand new root tips emerging.

However, I'm still not sure whether I need to pack it loosely or tight. What do you guys tend to do?

[estación seca]

It depends on your conditions. Overall I think tightly packed moss is better but the gardener must learn how to water it. Watering is different between the two methods. With tightly packed moss you leave a small gap between the top of the moss and the top of the pot. When you water you run the water over the top for just 1-2 seconds, no more. With the small amount of water that is provided this way there will not be enough to occlude all the air spaces. Soaking tightly packed moss will obliterate the air spaces.

In warm weather, when plants are absorbing water rapidly, they may use enough water that fully soaked moss will soon have more air. But in cooler weather the water may remain longer and suffocate the roots.

Cattleyas use more water than Phals. I commonly soak Catts. in moss during warm or hot weather. I don't do that with Phals.

If people frequently forget and soak plants in moss unintentionally, it might not be the best method for them.

[Kittyfrex]

In my experience, it's the same as previous post said. I suppose how good is each depends on where you are; my friends mom in UK fares extremley well with pure bark while i would need to water mine every day or two due to temperature.
Beside the temperature, airflow directs greatly how water retentive your substrate be, weather soil, moss, bark or something else, and it counts for all plants. The greater the airflow, the more water can the substrate be allowed to hold. If you put your orchid in a very windy place with moderate or warmer temperatures, even tight packed moss might seem to dry out fast.

My honest recomendation? Get two cheap store bough phals and experiment, potting them differently. Even the one you mess up can be saved (if you want to), or gifted later, once you see how your enviroment behaves.

[NatalieS]

I agree with both of the above posts as well. The medium that is best for your plants is completely dependent on the plant, your conditions, and your own habits.

Experimenting with different methods on plants you feel happy doing a bit of trial and error on is probably the best way to go if you are unsure about going all-in with a particular growing method, but I wanted to add here that observation is key.

No matter what you choose for your medium, just watch your plants carefully - does the medium appear to dry quickly, but is the plant still hydrated and growing? if the plant has been growing well in its previous medium, has the growth appeared to slow down or stop? is the moss wet for a long time? etc.

[Kittyfrex]

Another thing i forgot to mention is that your medium doesn't have to be one or another. I have phals in pure moss doing well, and some in layered moss-bark, also doing just as well.
Layering substrate instead of mixing lets you compact the moss some more since bark chips create enough air pockets, creating belts of moisture without drowning the plant.

I'm not saying it is a better method; it all comes down to what @NatalieS said - plant health, enviromental conditions and your own habits and desires.

[NatalieS]

Originally Posted by Kittyfrex

Another thing i forgot to mention is that your medium doesn't have to be one or another. I have phals in pure moss doing well, and some in layered moss-bark, also doing just as well.
Layering substrate instead of mixing lets you compact the moss some more since bark chips create enough air pockets, creating belts of moisture without drowning the plant.

I'm not saying it is a better method; it all comes down to what @NatalieS said - plant health, enviromental conditions and your own habits and desires.

I tend to layer bark and moss too, but that's because I have a preference for using bonsai pots (sometimes aesthetic preference trumps practicality ). Because of that, I can't visually check on how wet the medium stays lower down in the pot, so course bark always goes into the bottom of my pots to ensure reasonable drainage. It works for (most) of my orchids, but if I was growing in a much warmer environment, all moss might be more suitable for my habits - it really depends.

[Jmoney]

for what it's worth, the people I know who grow standard cattleyas in moss (quite well, I might add) all use tightly packed moss. I believe it limits how much water can be absorbed since it has limited room for "expansion".

I personally use this method for just about everything I grow without a pouch or spur.