Just bought 2 "Potinaras", what to do now?

[Tango]

Hi there,

I bought two "Potinaras" some days ago at an orchid exhibition in Budapest, two big beautiful yellow guys in bloom.

What should I do with them now? I think one of them may have bad roots, while the other looks pretty OK (thick silvery roots visible). Both plants have tight pseudobulbs and good light green leaves. The plants came from Taiwan and are tightly packed with old sphagnum in mini black plastic pots. Should I repot them now or should I wait until they grow? I like those huge flowers very much but I would like to do the best for the plant, even if I lose the buds. Advice is welcome!

Thank you very much for your help!

T.

[SouthPark]

The one that you suspect having bad roots should probably be removed form the pot, followed by inspecting the roots.

Have you got new media ready for repotting?

If you are a beginner, and first time growing this type of orchid, then I recommend a black plastic pot, with very good size drainage holes all along the bottom, and scoria rock. Have you got scoria rocks available in your area at nurseries or garden supply centres?

Average size of the scoria rock pieces usually depends on how big your plants are, and how big the roots are. This is the same if you are going to choose to use bark (eg. orchiata bark). It sounds like your orchids are good size. So biggest size bark pieces is probably what you need. Or .... if you can get scoria (aka lava rock), then 10 mm to 20 mm diameter (mixed) should work nicely.

An example is in the attached photo. The black coloured plastic drainage grates seen in the photo only for ensuring the bottom of the pots have no chance of sitting in water collected by the tray. It keeps the pots lifted up above any drainage water that comes out from the drainage holes during watering.

How to water? I use a water spray wand (with a spray nozzle). Water the media only. Any drainage water sitting in the tray will eventually evaporate.

Usual good orchid growing procedure is - good air circulation for both the leaves and the roots and media (so totally avoid still-air environment, such as inside a still-air room ----- not good; and provide good amount of light - natural light if possible for economic reasons; and provide comfortable temperatures for the orchid --- not too cold and not too hot. Temperatures that us humans find comfortable will be just fine for orchids too.

If you choose to use bark, then make sure to remember that dry bark repels water quite well, which means that if you have a plant in dry bark, then the water will just run straight through the pot - and the pot will dry out really quick - due to hardly any water getting absorbed by the dry bark. The solution to that is to dunk the bark in water for a while, to get water into it. Do this before potting.

If you use scoria (lava rock), then you won't have the above issue.

[Tango]

Hi SouthPark, thanks for your advice.

I have bark 10 to 20 mm prepared for them, that's what I normally use for the other plants. Lava rock is here only available through the internet.

Do you think I can repot the "Potinaras" now? Or shall I wait until they start growing?

T.

[cluelessmidwesterner]

As a newbie myself so I can only tell you what I've been told. A general "rule of thumb" with Cattleyas (which Potinaras are), is to wait until you see new root growth. Some Catts put out new roots when growing new pbulbs, or when the new pbulbs mature, or after the new pbulbs has flower flowered. Much depends on the genetic back ground of your Inter-generic Cattleya cross when root growth will start.

Having said that, much depends on the condition of the media they're presently in and the condition of the plants. If you suspect one having a bad root system then putting it in new media and a smaller pot-size is advisable. Generally speaking you would pot according to the size of the root ball rather than the top of the plant.

Sometimes there are times when you are in a pickle on what exactly is the right thing to do with a particular plant in your environment. For example right now I have a Inter-generic Cattleya I just purchased (Ctt. Warpaint) in which 50% of its genetic make-up is a Guarianthe aurantiaca a bifoliate Cattlya species. Even though its in highly questionable media, it because there is no new root growth. Bifoliate Cattleyas tend to react badly to having their roots disturbed at the wrong time by dumping all their roots. So I have to wait for new roots to start and hoping that the media doesn't cause the roots that are presently alive to die because its broken down.

(Potinaras are now called Rhyncattleanthe thanks to geneticists and the RHS - no matter how you slice it, its an Inter-generic Cattleya)

[Roberta]

That bark sounds much too small, will tend to stay too wet. 1 cm - 1.5 cm is good for Cattleya-type orchids, which need very good drainage and an opportunity to dry out between waterings.

[Ray]

Originally Posted by Tango

Do you think I can repot the "Potinaras" now? Or shall I wait until they start growing?

The best time to repot is just when new roots are emerging from the base of the plant, which for cattleya-types, is often when new growths emerge.

In the mean time, if you are very careful with watering - just moistening the medium and not saturating it - they will probably do fine while you enjoys the blossoms and wait for new growth to begin.

If the one with questionable roots turns out to have "bad" roots, go ahead and repot it, then keep it very warm. A seedling heat mat would be a good addition, as that can stimulate root growth.

Originally Posted by Roberta

That bark sounds much too small, will tend to stay too wet. 1 cm - 1.5 cm is good for Cattleya-type orchids, which need very good drainage and an opportunity to dry out between waterings.

Roberta - 10-20 mm is 1-2 cm.

[Roberta]

Oops... my bad. sorry.

[SouthPark]

Originally Posted by Tango

I have bark 10 to 20 mm prepared for them, that's what I normally use for the other plants. Lava rock is here only available through the internet.

Do you think I can repot the "Potinaras" now? Or shall I wait until they start growing?

Sounds good Tango. 10 to 20 mm will be just fine. Dunk the bark in water for a while before potting - to get them properly wet first.

Roberta mentioned that very small bark pieces, such as the smallest sizes you can get ----- will just stay wet for too long and smother/drown the roots. So use those 10 to 20 mm bark pieces. Don't use the teeny size (smallest size) ones - which need to be chosen for little seedling orchids - with relatively small pots with good drainage. This doesn't mean that smallest size bark pieces can't be used for big orchids too ------ (it could be used, but good control of watering and schedule would be needed - which could be too fiddly to deal with - and too dense a media breaks one of our golden rules of orchid growing - not good air circulation).

Since you suspected root rot in one plant - then that plant should really be inspected (roots and all - inspected). So a repot of that one will be due to no choice. That is, if we expect root issue, then there's no choice but to inspect, which a repot can then follow.

[Tango]

Originally Posted by cluelessmidwesterner

Bifoliate Cattleyas tend to react badly to having their roots disturbed at the wrong time by dumping all their roots.

I understand you, I bought a Catt. (Guarianthe) skinneri this summer and the company sent a chunk of a sick plant without roots (it was Claessen orchids). It took it 3 months to react and I guess it will take years before it blooms, despite being sold "blooming size".

I unpotted the suspect Rhyncattleanthe (thanks!) only to find a completely dead root system. I attach a foto

Thank you Ray and Southpark, I'll put the plant in fresh media and will wait until it feels like to resume growth. It is a unifoliate hybrid so I hope it behaves better than the Guarianthes.

Best,

T.

I guess orchid sellers are no ordinary plant sellers and distrust is rule number 1. It's incredible that such expensive plants come in such a bad status.

[SouthPark]

Tango..... you're most welcome. After looking at the photo ..... is that spaghnum moss in there among the roots? If it is, then that's probably what did it. The roots can get smothered - suffocate - in spaghnum that becomes too wet and saturated. I can't tell if it's really spaghnum in there. It just looks like it.

If it is ----- then remove as much of it as you can. Preferably remove all of it. Then pot into bark media.