Sphagnum - Loose or Packed Tight?

[Fairorchids]

I have also purchased from both OV & Christoffersen, and admire their results with the tightly packed spaghnum. Having read only the tail end of this thread, it appears that most are talking about large/mature Cattleyas. Size is an important consideration too.

I use spaghnum (coarsely chopped), but only for seedling plants up to 3" pot size, and mixed with about 1/3 seedling size bark & charcoal. That mix is only used in 3" plastic pots with multiple slits in the sides; I pack it fingertip firm, but not hard. This ensures a 3-4 day period of fairly consistent moisture + some air flow.

For 5" & larger I use clay pots, with granular mix II (Catt size bark/charcoal & super coarse perlite in 2:1:1 ratio).

For 3.1/2" to 4.1/2" sizes I use clay pots, with granular mix I (1/2 the bark is seedling size).

For a few larger plants, I use baskets with Aliflor (Leca) clay nuggets.

With this size based selection, I can water everything in the greenhouse at the same schedule (twice a week in winter, three times a week in summer).

My dad, who was old school, used exclusively clay pots, always with spaghnum/bark mix (3:1) and tamped down as hard as he could with a potting stock. Plants grew fine, but it made watering a more cumbersome process, as you had to water pots of different sizes at different rates.

[ozymand1as]

Originally Posted by SaraJean

Unpopular opinion: I love sphagnum moss for Cattleyas. There I said it.

Confession #2: I do pack it pretty firm.

Confession #3: It rarely gets a chance to dry out in my rainy summers.

Now for the context. Sorry, this is going to be long winded.
This all started when I was talking to Dr. Courtney Hackney when he came to speak at my orchid society. I had some questions about the Rupicolous Laelias and some mini Catts. I was struggling with them and he mentioned trying sphagnum with some reasons behind it. I looked up an article from the St. Augustine Orchid Society, read about it some more, and gave it a whirl.

...

I apologize for the long post and a summary is: These are just my observations. I like using it packed tightly in clay pots, where it doesn’t seem to hold too much water, and remains just airy enough to not rot the roots. here is that article I mentioned for anyone who hasn’t read it https://staugorchidsociety.org/PDF/S...ySueBottom.pdf

I am resurrecting this long thread, because the post above completely changed how I grow orchids.

I don't have a huge variety of plants and my growing conditions are my conditions, blah blah blah. That being said, I grow ever single one of my indoor plants in firmly packed moss as described above, and it is fantastic.

I was on the verge of giving up orchids because frankly the care was so time-consuming and stressful. Traditional media like bark was the worst, and my plants seemed to hate it, but even semi-hydro was ultimately a ton of work.

Switching to moss as described in Sara's post has been a revelation for me. The plants are growing beautifully, watering couldn't be easier. This method has completely changed how I approach the hobby, for the better! Thanks, Sara!

[estación seca]

I heard a lecture on growing Phals in tightly packed moss. I took notes but haven't written them up yet. The gist is the moss is never completely soaked. When the top is crisp just run water over it for one second. That water diffuses through the entire moss ball, leaving it well aerated.

At repotting the moss is dampened but not soaked the night before. It should be flexible, not crisp, yet not feel wet. Wrap it around the roots to form a large ball and stuff it tightly into the pot. That person uses transparent plastic pots so she can see roots. Leave a generous gap below the pot rim for water.

I don't use moss because S/H works well for me. But without S/H I would use moss.

When I receive a new plant in moss I keep it until repotting at the appropriate time. Catts, Catasetinae and Oncidiums use water much faster than Phals. I do soak the moss for those. Note my growing area is warm to hot much of the year.

Alan Koch lectured he uses 7 different potting mixes for different plants to permit watering his hundreds of thousands of plants once a week. Moss is one such mix. He does soak it. I have bought Catts from him potted in moss.

[ozymand1as]

That is similar to my experience.

The best part about watering sphagnum moss is that moss weighs almost nothing when dry. That makes it incredibly easy to tell exactly how much water is in the pot. Much more so than bark.

Unlike bark, firmly packed moss moss wicks moisture so well that surface dryness usually indicates the rest of the moss is almost dry as well.

I don't even feel the need to use clear pots with moss, although it is still nice to have them.

[sweta]

Originally Posted by early

When I first started repotting new phals, I did not connect
orchids or any of the media with causing me to have asthma. I have not had asthma for a few years and first blamed it on my cat, the outdoor weeds my dogs track in, but finally narrowed it down to the moss. I search on the web for same and found a few things that cited moss allergy but none in connection with orchid repotting or growing in moss.
Any one else have this allergy?

I cant believe that there is actually a thread on this and that I'm not alone in this. I have mild asthma and seasonal allergies which seem to have gotten worse since I started orchid hobby. Initially I didn't realize but over a period of time I've realized that when repotting orchids my asthma gets worse both with wet and dry sphagnum moss also I have allergic reaction on my skin in contact with potting media. Now I make it a point to wear long gloves to cover my hands when working with potting media as well as wear a mask to avoid inhaling allergens. Inspire.of my allergies I still love growing orchids.

[Roberta]

I don't have the problem, but know others who do have allergic reaction to sphagnum. There are spores, which are allergens. Certainly, nobody should ever work with the stuff dry... having it moist will reduce what goes airborne. Another common potting material that can be an issue - perlite (sponge rock). It crushes to a fine powder, and it's silica... something that you don't want in your lungs. Again, spraying with water can reduce the dust, but also stayi8ng upwind and wearing a mask are good practices with it.

[estación seca]

Almost no plants require one specific growing medium. You can find other media that don't affect your allergies. Most epiphytes can be grown in non-organic media like pumice, LECA, scoria/cinders or pebbles.

[isurus79]

Originally Posted by estación seca

Almost no plants require one specific growing medium. You can find other media that don't affect your allergies. Most epiphytes can be grown in non-organic media like pumice, LECA, scoria/cinders or pebbles.

This is a good point!