What are the reasons to underpot?

[Carlos]

Hi everyone,
just like the title says, why? as far as I can uderstand from browsing these forums is mostly because if you overpot you will most likely have root rot as the medium will take longer to dry out inbetween watering especially in the middle of the pot. Those that are experts with orchids wont have a problem with this (believe me, this is not my case ). Some say because some orchids like to have the roots tightly but having looked at most orchids habitat, i am mostly thinking Phal. their roots are spread across the trunk of the trees and therefore very spread out. Is there something i dont know that the expert know?

[orchidsamore]

You are correct about the plants in the wild, but what you do not see is the plants are much older.

When roots are pot bound the plant flowers much younger. You can over pot and still grow a good plant and flower it but it will take much longer.

It is easier to over water a pot with too much area but you can stop this with less watering or the use of more charcoal in your pots. The Charcoal holds almost no water,

I move overgrown 6 inch pots to 12 inch baskets with large charcoal filling the empty corners.(wood charcoal from barbecue supply). They continue to bloom as if they were never moved.

[Carlos]

Thanks reason I asked is because I have a glass vase which i was think of planting 2 or 3 Phals. I already have holes in this vase and I was thinking about the middle would be maybe to damp so I am planning in putting together a few peanut foam things and using something like a toothpick and build a pyramid out of them and put it at the bottom of the vase creating almost a hollow middle but the charcoal is also a good idea.

I was worried about the size thou because this will be much bigger than the pot I have them in at the moment.
When it complete I will take some photos and upload them

[nutgirl]

Another thing that works well if you are using a large container is to invert a net pot in the bottom before you plant. It takes up space and allows more drainage and air circulation.

I've used modified strawberry baskets when I didn't have the net pots.

Maureen

[trdyl]

Originally Posted by nutgirl

Another thing that works well if you are using a large container is to invert a net pot in the bottom before you plant. It takes up space and allows more drainage and air circulation.

I've used modified strawberry baskets when I didn't have the net pots.

Maureen

Great tip Maureen. I never thought of that.

I have used syrofoam peanuts in the past tho for large potted Phals in sphagnum moss.

[nutgirl]

Peanuts work too but I like to dunk my plants and the styrofoam always floated up disturbing everything.

I had a large Beallara that I did this to. After a year I unpotted to check things and the open space was full of happy roots. Lots of air and moisture I guess.

Maureen

[SOS]

Besides roots not being able to uptake all the moisture, some plants often bloom better outside the pot. Point in case, C. walkeriana. Underpotting them allows them to grow over the pot, while everything inside the pot offers, the extra moisture.

[Carlos]

thanks, so the reason to underpot is not one that we could say "THATS SO WRONG, YOU GOING TO KILL IT" but more of guide line for beginners and easy maintenance.

Originally Posted by SOS

Besides roots not being able to uptake all the moisture, some plants often bloom better outside the pot. Point in case, C. walkeriana. Underpotting them allows them to grow over the pot, while everything inside the pot offers, the extra moisture.

and it also does have it benefits for some plants.

[trdyl]

Another thing to keep in mind the longer organic mediums stay wet the faster it breaks down turing in to mush. Epiphytes such as Phalaenopsis, Cattleya, Oncidium need their roots to be able to breath. As the medium turns to mush, they sufficate and die.