The best potting media/compost for Cattleyas - in a temperate zone

[Dorsetman]

I added "in a temperate zone" since I am aware that what works for me in England,
and maybe in the northern parts of USA is likely to be different from what works for our friends in Malaysia etc.
( For example, Vandas grown in baskets with no compost go down-hill in UK)

In my greenhouse, coarse bark ( fir or preferably pine)is good for Catts (if they have a really good set of roots), in winter but needs too frequent watering when plants start to grow especially in summer.
( Some of my catts do grow in winter too, since I use some supplementary lighting.)

Medium bark ( say 15mm pieces ) 2 parts and spagnum moss 1 part is good in the summer, but maybe too wet in the winter.

I have been thinking of switching to a smaller size medium pine bark ( not going down to seedling bark size with pieces in the 7-12mm size range, ) alone, no additives,
but having spent the last few years trying several different mixes which I won't bother to list , and without getting it really good, I thought I would take a census of what you-all think ?

[cakedaddy]

I will be watching this thread...thanks for starting it! I killed catts when I first tried them...and if I had to guess why, I would say underwatering! I've had people tell me that this couldn't be the case, but I beg to differ.

[EMos]

I'm still experimenting here too, but I found that a Coarse pine bark/charcoal/lava rock mix works for me - With the watering it's really a question of observing the catts, as the regime for summer and winter is likely to be different. I found that they can easily dehydrate if left unwatered for too long in summer too.
I am very keen to learn from what other people use and what could possibly be the best media. I know that a lot of people grow Catts in direct perlite, I would like to hear from people who are using this media, and let us know how successful they are in using it.

[Roy]

In my post, Catt Rosella Bells, you can see the plant growing in pure perlite. Its 140mm pot also. When I received the plant it needed repotting because os size. There wasn't one bad root on it except for the dead centre, which is normal. I've repotted it into the same grade of perlite. The nursery it came from I deal with a lot & all their plants are in perlite, including Vandaceous, no root problems. And Vandaceous plants I have with root probs I put straight into perlite & they come back very well. In all, it apears to hold moisture without being wet. It works well for me using 15mm bark 50% & perlite 50% also.

[EMos]

Thanks Roy,
generally to what frequency do you water your catts in summer and winter?

[Roy]

Eric, in summer I need to check every day as the plants dry out very quickly. I may need to water or mist spray them every day as they dry out quickly even tho the humidity is high in the greenhouse. I do them whilst misting the Vandaceous plants & Paphs. Everything is in the one house. In winter, the plants in pots with mix, I check the drain holes, if the mix is dry I water, if its moist I water the next day.

[Dorsetman]

Thanks for the contributions ; the idea of using a Perlite/bark mix, cutting out the moss is attractive, and I'll do a little experimenting with some plants. In general I often pot new plants other than catts in Perlite on arrival, because watered once, it drains well, but holds a little moisture for a long tome whilst new roots develop. In fact I grow all my Catasetums in this material and most of my dendrobes too. There is a problem in getting coarse Perlite in UK , and I get the largest size I can and then washit - usually by half filling a container with water and then tipping in the Perlite, and repeatedly pushing it below the surface. What floats I use ; what sinks I discard. This removes the dust and fines, which gives a coarser material at the cost of throwing 20% away.
And btw I have a large Vanda which has been in just Perlite for maybe 7 years or more ; it is healthy, grows, and flowers - but not as frequently as the ones I grow in straight bark , in fact it is in spike now, but I can't remember the last time it flowered.

[espranch]

As far as my cattleya, I use a 60% medium fir/pine bark mixed with20% charcoal, & 20 % perlite. For phalaenopsis, I use Large fir/pine bark, as their roots are twice the size of cattleya roots. Charcoal & perlite stays the same. (20 % for each) I also use tree fern slab for mounting cattleya. Other kinds of orchids I do in different ways...the fine rooted ones seem to like to be potted in small white rocks. Works for my orchids! Betty :-)

[pavel]

So much depends upon one's growing conditions that I don't know that there is such a thing as one ideal mix for everyone. For that matter, even the catts' parentage can make a difference. I have known folks who grow catts quite nicely in 100% sphag. I myself once had a catt that was completely bareroot sitting in a pot that grew some phenomenal roots. However, my typical mix at present is large coconut husk chunks (0.5-1 inch), large grade charcoal, and hydroton/aliflor in an approximate ratio of 1:1:1

[Halloamey]

Geoff, here in Bremen, I am planting all my Catts in a 50:50 bark, hydroton mixture. And for plants in the greenhouse, they are in 100% hydroton, as they are watered every alternate day.