how to tell when sphagnum moss needs replacing
 

i just replaced the moss for my encyclia polybulbon. It was quite old. That beng said, i took some pics and i was curious how you can tell it needs replacing. This is the old stuff. How does it look?

(by the way i had just got done watering it when the pics were taken)

It looks bad. Old sphagnum compacts down and the individual moss parts look broken and distorted. The moss gets a dark brown hue.

For plants that need to stay moist, sphagnum lasts only a year or two. Most people would repot a plant in sphagnum every 2 years at the most.

When Epidendrum polybulbon is happy it will grow so fast you need to repot every year.

That moss is probably a couple years old.

I thought its an Encyclia, did they change the name? it grows quite slowly, probably not enough light. Until recently I had it under a grow light with my african violets. I wish i had better grow spaces

Taxonomists have called orchids by many different names, and frequently change their minds. This plant used to be called Epidendrum polybulbon. A lot of former Epidendrum species are now in Encyclia. I just forgot. You will see the plant under both names.

It likes coolish temperatures, high humidity and a lot of water. It doesn't need a lot of light; less than Cattleyas, the same or a little more than Phalaenopsis.

Is that greenish-blue part of the sphagnum something to be concerned about? I've noticed the same in my Maxillaria tenuifolia but so far the plant looks ok and the structure of the sphagnum is still holding up.

It's algae, which, unless it overgrows everything and suffocates the roots, is not an issue.

It might, on the other hand, suggest overfeeding.

Personally, I think one year is the maximum life for sphagnum.

I replace mine once a year, and my orchids seem to like it.