# Overpotting culture



## Carper (Oct 12, 2014)

There's been questions on the effects of overpotting, but with care and plenty of observations of your plants requirements and cultural needs, you can still attain solid root formation. I've found this has definitely benefitted my plants in there overall structure, however, each species and hybrid has to be treated accordingly. The following having filled there respective pots. 

1. Paph philippinense - 7.5 litre pot
2. Paph Taiwan - 5 litre pot
3. Paph rothschildianum - 7.5 litre pot

Gary
UK


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## phraggy (Oct 12, 2014)

Brilliant as usual Gary. How large were the plants when you put them in these sizes of pots? Is this orchiata 12-18mm with added sponge rock?? Looks you are about to split them!!

Ed


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## troy (Oct 12, 2014)

Monster plants, wow!! If you split that phillipinense I'd buy a growth


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## Carper (Oct 12, 2014)

phraggy said:


> Brilliant as usual Gary. How large were the plants when you put them in these sizes of pots? Is this orchiata 12-18mm with added sponge rock?? Looks you are about to split them!!
> 
> Ed



The roth was a 2 growth, phili a 6 growth & Taiwan 2 growth when I bought them. I roughly doubled the size of the pots when I repotted last time. I've had them all a few years now. Yes, for this size pot I will use this size min with a top dress of the 9-12mm. Unless these plants suffer with their growth or blooms, they will just get repotted and into larger pots if necessary. I've not had plant that has suffered because of a size related issue so until that happens I'm hoping they grow on!!

Gary


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## troy (Oct 12, 2014)

I don't understand how you are successful with this method, I've killed 3 plants overpotting. how often do you water? What do you fertilize with, what strength? I just got three plants and slightly underpotted to get ready for winter


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## gonewild (Oct 12, 2014)

The only reason "over potting" causes plant death is because the correct moisture amounts were not maintained.


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## Carper (Oct 12, 2014)

gonewild said:


> The only reason "over potting" causes plant death is because the correct moisture amounts were not maintained.



Right Lance,

I've spent a lot of time experimenting, including holding my pots, looking into the media, feed strength, air movement, drying times etc. I will only water when they need it. If in doubt, I don't!!!. You won't kill a paph in a short period through shortage of water. Most of my plants are drying out on the day they've been watered as I increase the heat. If I think they need moisture, I'll foliar feed until I know it's good to go through the pot. Any plant that seems to be holding excess water either gets repotted into fresh medium or placed on the heat mat.

Gary


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## Rick (Oct 12, 2014)

I've found that moisture content in open mixes becomes much less of an issue when you cut feed strength down (to what most would consider "starvation" level).


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## troy (Oct 12, 2014)

Keeping the fertilizer down = less decomposition of media? Overpotting with fresh media - changing once a year? It looks like yur using large orchiata with perlite? Orchiata is ph neutral, do you use fir bark?


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## Justin (Oct 12, 2014)

nice growing! i agree mature multifloral Paphs do very well with big pots. is that your Taiwan division from Orchid Inn?


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## dodidoki (Oct 12, 2014)

Carper said:


> Right Lance,
> 
> I've spent a lot of time experimenting, including holding my pots, looking into the media, feed strength, air movement, drying times etc. I will only water when they need it. If in doubt, I don't!!!. You won't kill a paph in a short period through shortage of water. Most of my plants are drying out on the day they've been watered as I increase the heat. If I think they need moisture, I'll foliar feed until I know it's good to go through the pot. Any plant that seems to be holding excess water either gets repotted into fresh medium or placed on the heat mat.
> 
> Gary



It is in sharp contrast with "paph in stagnant water" theory...


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## troy (Oct 12, 2014)

Yes


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## Carper (Oct 12, 2014)

Justin said:


> nice growing! i agree mature multifloral Paphs do very well with big pots. is that your Taiwan division from Orchid Inn?



The bigger multis do seem to thrive in the bigger pots. I bought a large David Ott in June which was potbound in a 3 litre, had to cut off the old pot, repotted into a 7.5 litre and I've just noticed new roots at the base. Yes the division of Taiwan I got from someone in the UK who originally purchased it from Sam.

I have been reducing the feed strength to half what I had been using and still getting vg results Rick. This should only result in the media lasting longer as I can now tell when the orchiata needs replacing for my plants to still get full benefit.

I only repot Troy when I feel the media needs it. This all comes down to water retention, drying times and root/foliar growth. I only use orchiata as it has suited my plants the best by far. I've tried and tested other media mixes with limited success.

Gary
UK


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## Bjorn (Oct 12, 2014)

Matter of watering really. Also the positive effect of reducing the fertiliser additions. Plants grow better with room for the roots, my benchspace does not allow that! Perhaps wider pots are better than taller?


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## gonewild (Oct 12, 2014)

There is an underlying issue also with root efficiency. Roots, just like water and air pipes, have more efficiency with less turns and corners.
More efficient roots mean the plant can get the required amount of water from dryer soil. Also roots that are crammed together in a small pot are less efficient because a large percentage of the root surface is actually in contact with other root surfaces rather than mineral rich media.


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## gonewild (Oct 12, 2014)

Bjorn said:


> Matter of watering really. Also the positive effect of reducing the fertiliser additions. Plants grow better with room for the roots, my benchspace does not allow that! Perhaps wider pots are better than taller?



Wider is better than taller. But you must adapt the watering procedure to account for the media depth. 
In a deep pot there will be a horizontal zone or layer that is the best root area depending on how and when water is applied. 
Also with deep pots there is an effect of gravity where the plant must lift the water higher to reach the leaf tips. It takes energy to raise water upward.


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## Carper (Oct 12, 2014)

A small note is that during my experimenting I decided to put extra holes in the sides of my pots. The size depending on the pot size. This has made the drying of the media more even especially with the good air circulation.

Gary


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## troy (Oct 12, 2014)

Plant roots in sitting water?


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## Berthold (Oct 12, 2014)

gonewild said:


> Wider is better than taller.



Yes because You have more surface of substrate to the air and the oxygen in the air will kill the anaerobe bacteria in the substrate. You have to increase watering for wide pots but water is cheap.


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## troy (Oct 12, 2014)

Everytime I had plants submerged they died


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## Stone (Oct 12, 2014)

gonewild said:


> Wider is better than taller. But you must adapt the watering procedure to account for the media depth.
> In a deep pot there will be a horizontal zone or layer that is the best root area depending on how and when water is applied.
> Also with deep pots there is an effect of gravity where the plant must lift the water higher to reach the leaf tips. It takes energy to raise water upward.



Gary...Excellent orchid growing observations and culture. Hats off!

Lance...Plants do not ''lift'' water. The water is taken up via capillery action. As water is transpired from the leaf, so more is drawn up to replace it. That's how a redwood can get water 300 feet high. The plants do none of the work and use zero energy for water uptake. They use a little energy to hold the 5% they use and the rest goes right through. 

As for deep vs wide, I know a nurseryman who swares he gets much better growth in Paphs with deep pots. Yet I have seen fantastic growth with a very shallow ''container''...namely the floor of my g/house. 1 brick deep and 1 metre wide. I think what's important is the root can freely travel in a straight line-as you mentioned- and this somehow boosts the plant response


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## Ozpaph (Oct 12, 2014)

Great growth - keep doing what you're doing.

Most paph growers, here, use tall pots with success - might be a climate thing.


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## gonewild (Oct 12, 2014)

Stone said:


> Lance...Plants do not ''lift'' water. The water is taken up via capillery action. As water is transpired from the leaf, so more is drawn up to replace it. That's how a redwood can get water 300 feet high. The plants do none of the work and use zero energy for water uptake. They use a little energy to hold the 5% they use and the rest goes right through.


I used the word "lift" to try to simplify my statement. (Lift, meaning moved from soil to plant.)
Water is taken up by capillary action but the capillary action is controlled during the process of transpiration. Transpiration control uses energy from the plant.


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## Ray (Oct 13, 2014)

troy said:


> Everytime I had plants submerged they died



Of course. You drowned them.

If, on the other hand, the roots had grown down into the water, they would have tailored themselves to that environment, and would have done fine. In fact, you'll often see that roots in the liquid are fatter than the ones above.

_________________________________________________

There has been some good feedback on the use of large pots here. It all comes down to moisture management, as has been discussed.

Evaporation occurs at interfaces, with the predominate being medium-to-air and medium-to-pot wall (even if it's plastic). The way most people pot up their plants and water, as the medium dries, it's the center of the medium that does so last - right in the middle of the root mass - and that "soppy center" can suffocate the roots.

That is not an issue at all with semi-hydroponics, as the LECA wicks the moisture quite uniformly, and can be avoided in traditional media that don't wick well by making it open and airy, so the water in the center can evaporate faster.

Then, the only other concern with "overpotting" is making sure the plant is very mechanically stable in the pot while its roots take over, as even the slightest wobble will cause them to stop growing.


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## troy (Oct 13, 2014)

I tried that they all died semi hydro doesn't work for me


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## Carper (Oct 13, 2014)

While I am on the subject of large pots I will throw another open question.

By attempting to grow a larger root system, is this taking anything away from the bloom ie, putting it's energy into growth instead. As the plant grows in size will it produce larger spikes or is that in the DNA of the plant?

Gary


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## Berthold (Oct 13, 2014)

Carper said:


> While I am on the subject of large pots I will throw another open question.
> 
> By attempting to grow a larger root system, is this taking anything away from the bloom ie, putting it's energy into growth instead.
> Gary



A species like Phragmipedium kovachii needs a root system of at least 5 m long to support its very big bloom in development. 
A large pot filled with roots can only be an advantage.


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## gonewild (Oct 13, 2014)

Carper said:


> While I am on the subject of large pots I will throw another open question.
> 
> By attempting to grow a larger root system, is this taking anything away from the bloom ie, putting it's energy into growth instead. As the plant grows in size will it produce larger spikes or is that in the DNA of the plant?
> 
> Gary



larger plant equals larger spikes and flowers... up to the maximum size allowed by genetics.


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## Ray (Oct 13, 2014)

troy said:


> semi hydro doesn't work for me




That just tickles me! Not picking on you, Troy, just using this as an example.

When folks fail with sphagnum, the usual comment is "I kill everything I put in sphagnum", acknowledging that the grower just doesn't know how to use it properly. However...

When someone fails with S/H culture, the response is that "it" doesn't work, rather than "I didn't do it right".


Ray Barkalow
firstrays.com


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## troy (Oct 13, 2014)

My humidity is too high to use semi hydro, I get rot problems


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## gonewild (Oct 13, 2014)

troy said:


> My humidity is too high to use semi hydro, I get rot problems



Simi hydro should result in less rot problems than organic media.


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## troy (Oct 13, 2014)

I would have to see it to beleive it, can you show me pictures? plants sitting in water in my grow area die, thats my experience, I water let dry out mostly, then water agian, it's easy for me, I'm not use to semi hydro, if you would want to explain the dynamics, I would listen very carefully and possibly try it


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## gonewild (Oct 13, 2014)

Ray can explain the dynamics.

My experience growing in leca with pots standing in water is that it is impossible to over water them.


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## troy (Oct 13, 2014)

My nights here 64° farenheit my days are 73° farenheit with 70 '/. Humidity night and day is that good for semi hydro?


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## Stone (Oct 13, 2014)

troy said:


> My humidity is too high to use semi hydro, I get rot problems



Its not the humidity. During a wet monsoon (which is a massive WIND system), the plants are saturated for days on end and the humidity is upwards of 100%. Air movement (or not enough) is your problem. If you cannot see the plants leaves moving, you don't have enough air. If we could arrange a stiff breeze in our growing enclosures we would have fewer problems. Remember too that air circulation at the roots is directly related to air circulation outside the pot. If you have rot problems, always look to the issue of air first!


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## troy (Oct 13, 2014)

I have 3 fans, my plants dry out 3 days after I fertilize, I have to water agian. In summer after 1 day I was rewatering


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## Ray (Oct 14, 2014)

I guess the real question is "Where, in the plants' root growth, did you move them into S/H?"

We expect the existing roots to succumb after moving the plant into S/H. When they grew, they "tailored" themselves for an entirely different environment, so will be less-than-optimal for the new conditions. If we time things right and move the plants when brand new roots are emerging from the base of the plant, they will be optimized for the new conditions, and will support the plant. The greater difference between old- and new conditions, the more rapidly the old roots will die and rot.

Most of the problems folks have with a plant _established in S/H culture_ is too low humidity, which results in excessive evaporative cooling of the root system, in the open, airy medium. That is particularly an issue with phalaenopsis grown in homes when the thermostats are pushed down at night in the dry winter - the result is roots too cold to survive. In high humidity, there is little-to-no evaporative cooling, so that's not an issue.


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## troy (Oct 14, 2014)

Thats interesting to know, thank you, I found your semi hydro culture website I'll read up on that, on another note bsides copper sulfate what other copper complex will work, for orange rust fungus eradication?


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## Carper (Oct 14, 2014)

Thanks everyone for the input and with nothing in the way of negative comments, but possible alternatives I'll take this forward just a bit more. As I've stated and others have about the benefits of a larger root system, how far do you go with reference to pot size. I've seen seriously rootbound plants which could then reduce the surface area for nutrient uptake, so If I can get fast growth by successfully overpotting, without dividing or the plant suffering in any way, where's the limit?

Gary


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## gonewild (Oct 14, 2014)

Carper said:


> where's the limit?
> 
> Gary



The edge of the pot is the limit.


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## Berthold (Oct 14, 2014)

Carper said:


> I've seen seriously rootbound plants which could then reduce the surface area for nutrient uptake, so If I can get fast growth by successfully overpotting, without dividing or the plant suffering in any way, where's the limit?
> 
> Gary



The limit is defined by the genetics of the species of the plant. Have a look for the largest plant clusters You find in nature and You know about the limit.


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## Rick (Oct 14, 2014)

Since I've gone to baskets for a lot of plants the physical limit of root growth doesn't appear to be diffined by the edge of the container (as in a pot). For some of my plants that are pushing out of the 1st basket, I've nested into a bigger basket. So far they are going to the edge of the bigger basket too, and (for the Kolo's) probably ready to go a size up!


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## Rick (Oct 14, 2014)

Carper said:


> A small note is that during my experimenting I decided to put extra holes in the sides of my pots. The size depending on the pot size. This has made the drying of the media more even especially with the good air circulation.
> 
> Gary



Transition to baskets:wink:


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## Rick (Oct 14, 2014)

Carper said:


> While I am on the subject of large pots I will throw another open question.
> 
> By attempting to grow a larger root system, is this taking anything away from the bloom ie, putting it's energy into growth instead. As the plant grows in size will it produce larger spikes or is that in the DNA of the plant?
> 
> Gary



DNA will define the ultimate size of flowers and spikes.

But larger roots support larger leaves, and ultimately plants that are more resilient to disease and culture upsets. When the plant goes into sexual reproductive mode (i.e.flowering) its going from a position of good health and not the last gasping effort to get its genes into the next generation before colapsing (the "bloom itself to death theory").


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## Rick (Oct 14, 2014)

Carper said:


> The bigger multis do seem to thrive in the bigger pots.



Back when I was using MSU at 1/2tsp/gall I couldn't get multis to survive in pots unless drastically underpotted.

I have old ST posts of blooming (18 -24") size supardii and stonei in as little as 2" pots! Attempts at moving them to greater than 4" killed the roots and I'd have to start over again in a small pot (or they died).

With reduced K I got succesful root growth in larger pots (when I still used pots) but still had to be careful on water and potting mix age/condition. 

With reduced N I'm getting to use big pots and almost as much water I can throw at them.


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## Carper (Oct 18, 2014)

Over the last several months Rick, my feed strength has gradually reduced anyway as I'm getting just as good results. My only concern with basket culture is that when the roots appear outside the medium, do you repot as they seem to die when fertilized directly. My kovachii is still in basket culture and I recently replaced the medium and it's on the go again and this seems the only method I can get use to keep it alive!!

I may try out the method on a few more for a trial.

Gary
UK


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## Brabantia (Oct 18, 2014)

Carper said:


> Over the last several months Rick, my feed strength has gradually reduced anyway as I'm getting just as good results.
> Gary UK


You have reduced at which Nitrogen concentration and what is your feeding frequency?


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## Carper (Oct 18, 2014)

Brabantia said:


> You have reduced at which Nitrogen concentration and what is your feeding frequency?


 
It's around 20 ppm N I think and I feed approx. once a week but as the days shorten/lower light levels are now here in the UK, feeding will be from 7-14 days depending on the medium and when I feel the plant needs it. I am experimenting with foliar feeding at the minute with vg results which I intend to continue with at least weekly.

Gary
UK


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## My Green Pets (Nov 10, 2014)

Thank you for this thread! I recently overpotted a roth from a 6-inch to a 10-inch pot and was not sure about it, but I feel more confident now!


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