Sand plunge for Pleiones?

[Alex]

I am idly wondering about growing Pleiones in my plunge (appropriately shaded, of course). Has anybody used a sand plunge for Pleiones, and if so has it been successful? I am assuming that clay pots will be required, but would the usual sphagnum moss-based mixes be OK in a plunge?

The drive behind this is that I am running out of greenhouse space and have some of the Pleiones tucked away in shady spots which I don't think are to their taste....but I could accommodate these in spare space in the plunge. And of course it may have the same benefits it does for bulbs in keeping the compost evenly moist without going through the wet/dry cycles that are otherwise part of pot culture.

Cheers,

Alex

[mark smyth]

I would have been interested in what people had to say

[SteveC2]

If space is an issue, put them outside!  I am not sure they need too much shade, on the north side of the house they get early and late sun.  Most of mine have been out since May and thanks to actually having a proper summer I have some huge bulbs! Of course it is very dry in this part of the country so I do not have to worry about rain over wetting the compost.
Seriously I can see no reason why they shouldn't grow well in a plunge, (outside I assume), although I wonder if the wet/ drier cycle might actually be preferable to a wet/ wet cycle?

[mark smyth]

Up to 2010, when winter frost killed them, I grew Shantung outside on moss covered peat blocks. I've also seen them growing outside in very gritting soil in raised beds

[SteveC2]

Just for clarification I meant put them outside for the summer.  I have a surplus of Tongariro and so over the last three years have tried growing them in various outdoor sites with one consistent result; mush!  Even last winter when we had very little frost, what we did have was enough to kill them.  Mine spend the winter in paper bags so space really is not an issue.

[Darren]

I'm with Steve on this one.

Though in a wetter part of the country I find my Pleione do much better outside for the summer in almost full sun. I also think Steve is right about the wet/dry cycle as mine are in un-plunged clay pots which need watering almost daily in mid summer but this means extra opportunities to feed them!

Autumn flowerers may like the extra warmth they get under glass but I no longer grow any of these anyway.

Having moved the Pleione around a few time in recent years I've observed the following:

Some species such as forrestii seem to do better if I keep the rain off them by keeping them under a polycarbonate sheet propped over them - but still fully exposed to the air around the sides.

They are perfectly happy in full sun here - provided they go out before the leaves develop much - moving well developed leaves out from the shade into full sun causes them to scorch. Albino forms with pale foliage are especially vulnerable. I move them outside immediately after flowering and after the last frost - generally late April here. Then the leaves develop in sunshine and are adapted to it.

For a few years I tried putting the pots in a shadier spot under some trees but they did not respond well, became infested with aphids and fungal pathogens and eaten by slugs. They are much happier in the sun and this year (like Steve says) have nice big new pseudobulbs.

I always move them back under glass in late september to let them dry out before dormancy.

[Pete Clarke]

I think Darrren has summed up the way to grow most Pleiones outside, well and I follow the same method.
Many of the leaves now look rather light green and tatty, but good,big bulbs are resulting.

[Alex]

Thanks everybody, grateful for your replies. I know quite well that Pleiones are amenable to outside culture (in Summer), and grew them all this way when I started...I was just wondering whether anyone had used a plunge as I have some spare space in mine, wondered how they'd like the constant moisture (not a wet/wet cycle, or a wet/dry one, but rather constant lower level moisture) and very importantly, if they were in the plunge I'd get to appreciate them at a workable height, not on the ground! I don't really have non-plunge bench space.

Cheers,

Alex

[SteveC2]

I have my doubts about constant moisture.  One of the problems I find with not repotting annually is that the moss breaks down and stays rather soggy, causing poor root growth.
But in the end you know that there is only one way you will ever find out if they like the plunge and that is to give it a try.  Just start with something cheap and vigorous.  Got any Tongariro?

[Steve Garvie]

I have grave doubts about using a sand plunge -especially when it comes to some of the more awkward to grow epiphytic/lithophytic species.

Forrestii, humilis and albiflora have been growing well for me in free-standing plastic pots in a very open mossy mixture. I use cheap plastic pots and melt numerous holes in the pot sides with an old soldering bolt. The roots often grow through these holes and I suspect that this achieves a good balance of moisture and aeration to the roots. I have the pots free-standing within an old Access frame in a lightly shaded area.
The pots stand on shallow trays containing saturated sphagnum moss which act as a reservoir source for moisture which is drawn up through the damp medium in the plastic perforated pots and evaporates away. This gives a constant flow of aerated water through the growing medium but prevents excessive salt build-up ( I try to use rainwater whenever I can).


I would avoid clay pots for growing the more difficult Pleione species. Just check out the crystallised "salts" that often build up on the surface of clay pots due to the process of evaporation and underlying capillary action "sucking" up more water from the surrounding plunge. This water contains small amounts of minerals which become deposited on the surface of the clay pots -I am convinced that these salts will kill the delicate roots of species such as forrestii and albiflora.