Proper substrate for Osp. Brazilian Sun 'Samba'

[awharvey]

My wife and I recently had our 28th anniversary, which we learned was our "orchid" anniversary! So to celebrate we got ourselves a beautiful Osp. Brazilian Sun 'Samba' from Palmer Orchids. It arrived in a 3" pot with two gorgeous spikes in bloom. The plant tightly fills the pot, but you can tell the substrate is entirely sphagnum. Is a proportionately small pot with only sphagnum a good idea for this type of orchid? It definitely holds water much longer than our other pots, which are proportionately larger and use a more typical orchid bark/charcoal/sphagnum mix.

[Ray]

There is no "good", "bad", "correct", "incorrect", or "perfect" medium for any orchids, as that's putting the cart before the horse.

First, consider what the plant needs. Being an "oncidium-type" plant, it likes nice, even moisture for its relatively fine roots, but also needs plenty of air to them.

The next part of the equation - that we do not know, but you do - is what are the growing conditions you can routinely provide, and how do they affect the drying of the medium.

The third factor is just how much do you and your wife (congratulations on the anniversary) like to "mess with" your plants?

Then put those together to find what works best for you.

If your environment is very dry and you are growers that tend to "admire from afar", then sphagnum might be fine. If, on the other hand, you have high humidity and you like to water a lot, the sphagnum will soon be a root-suffocating mess, so something coarser and inherently drier is a better option.

[estación seca]

Oncidiums use a lot of water, and should never dry completely. Note how heavy it is when you water, and how quickly it becomes light. Many commercial growers use sphagnum for Oncidiums.

[awharvey]

Ray,

Okay, thanks. It seems pretty happy, though snug in its pot, so I'm inclined to leave it alone.

---------- Post added at 01:12 PM ---------- Previous post was at 01:10 PM ----------

That's good to know. Thanks!