Calanthe compost query

[Houseslippers]

I've now added Calanthe tricarinata - having never tried any Calanthes before - to my small Cyp collection, to grow in a pot alongside them outside in summer, with plans to add more Calanthes in time. My question: what compost do you Calanthe enthusiasts grow your plants in? Cribb & Bailes in 'Hardy Orchids' recommend either an 'Orchid grower's epiphytic mix' - a blend of 6 parts medium orchid bark, 3 parts sphagnum, 1 part perlite, 1 part charcoal, 2 parts beech/oak sieved leafmould - or a 'Woodland terrestrial mix' - 2 parts loam, 2 parts beech/oak leafmould, 1 part sphagnum, 1 part sharp sand or crushed grit, hoof & horn base dressing. That's two very different composts, then.... and I don't have any oak/beech leafmould to hand either.

Might Calanthes grow in a coconut husk chunk-based mix? And what sized pot - a big one, like Cyps?

[Neil]

Its all about finding the right mix for you growing conditions! Not sure about what size pot you would need.

Here is some more,different, info about soil mix

http://lanesidehardyorchids.com/catalog/calanthe_orchids.php

[Maren]

Here  is a mix I have been using with good results. It's Ian Butterfield's recipe and he grows some amazing Calanthes.

Ian's compost   buckets (your ordinary 5litre bucket - it said litres before which was a mistake on my part)
Peat…………………...   6
Fine bark…………......   6
Perlite………..…….....   1
Vitax Q4………..….....   8cm pot full
Fish, Blood & Bone....   7cm pot full   
Dolomite Lime…….....   7cm pot full

[Houseslippers]

Thanks, Maren & Neil. Neil, I looked at Jeff's site as you suggested and found another compost mix there, so clearly your point is well-made - find a mix that suits my growing conditions. I don't quite know what these are yet (I've never grown Calanthe before) - except that the growing site is a suburban back garden in south London on the north side of a greenhouse, raised off the ground on a bench, with some frost 'relief' from the urban situation, and low rain in summer, so a moisture retentive, open woodsy mix seems right according to all the recipes so far. Maren, there's nothing like the word 'amazing' to get the gander up, so I think I'll use a version of Ian's mix, substiututing fine grade coco husks or coir for the peat - not so moisture retentive, to be sure, so more attention to watering, but I do try to avoid peat these days if i can.

Does the pH of the compost matter - or is this a species specific consideration? Ian adds dolomite limestone so acid pH is not required?

[SteveC2]

It seems to me that the commonly available Calanthes, (I have tricarinata, discolor, sieboldii and some hybrids), will be quite happy in your mix but I'll pass on two pieces of advice which seem to work for me.  The first came from Jeff at Laneside and was "throw water at them!"  When questioned he added, "when they are growing."  I pretty much watered my collection every morning last summer and as there are big fat shoots appearing with flower spikes already poking through, that seems to have worked.  The other piece of advice was to feed very regularly, to alternate tomorite and seaweed extract on a weekly basis.  i suspect that this will be vital if you use the mix you mention.  My compost is very similar to the bark, peat, perlite mix recommended by Maren.

A third piece of advice comes to mind as well.  Watch out that your north aspect isn't too shady.  I think these are happier with a little more sun than your cypripediums will want.

But in the end we come back to my usual mantra, suck it and see.  Whatever works for you! 

[Tony Willis]

I grow the same ones as Steve except the hybrids and I would say keep them frost free. I had them plunged in a sand frame last winter and they were devastated. This winter I have kept them just above freezing.

[SteveC2]

Mine are also kept frost free.  This means that last year's leaves are still green and hopefully helping the plant to build itself up.  I'm sure that they would be leafless at best if outside in the wind and probably dead given the winter we've had.  I'll only cut off the leaves if they get tatty or in the way of new emerging shoots.

[Maren]

Hello Tony,

I believe the compost should be neutral. I agree with other correspondents that moisture all year round is important as well as feeding  a varied diet. They don't appear to like frost and I have overwintered only two, and only just, pretty much by accident three winters ago. I don't think they would have made it through the last winter or the one before. One of them was C. sieboldii, which took a long time to recover, and the other C. ceciliae, a wonderful skyblue variety, with no hint of pink or violet. It's a pity I didn't take a picture when it flowered, but I have nursed it back to growth and expect a flower spike or two next year.

[Tony Willis]

I should have said that I got my sieboldii from Ian Christie who had it growing and flowering beautifully outside in what is a very harsh climate. He just took me a piece off the plant and yet with me it was killed by last winter's weather.

[Maren]

Tony,

did you ask Ian what he did with the C. sieboldii during the winter? You saw it in flower, that must have been in the spring. Maybe he covered it or moved it? sometimes a big mulch of leaves or needles can be helpful, or a mobile cold frame. - But I won't risk it any more.

[Tony Willis]

Maren I have had the plants many years and cannot remember the conversation but get the impression that the plants grew with no special attention. Not the situation with me.