Cat Litter in orchid compost - a season's experience

[Maren]

Hi,
earlier this year I ran out of supercoarse Perlite, which I use in my pleione compost:

1 part sphagnum moss (chopped into 1 inch lengths)
1 part Melcourt potting barg, sifted
1 part supercoarse Perlite.

It was only a small batch of pleiones that had to be potted, so I substituted the perlite with the cat litter from Tesco, which consisted of clay granules about 2mm in diameter.

While harvesting my pleione pseudobulbs, I found that all the cat litter had migrated to the bottom of the pots and combined into a dense layer which was dripping wet, and so was the rest of the compost. By the way, I stopped watering the pleiones at the beginning of October and those in my normal compost were nice and dry. The pleione bulbs in the cat litter compost were not worth keeping and went straight on the compost heap. - I clearly did something wrong but I don't think I'll use it again. It pays to have the same compost for like plants, so that they can be treated with the same regime of watering, feeding etc.

[Slug Killer]

I have used it for Pleione without problems as well as Cyps (moler clay cat litter, non clumping) but prefer perlite (cheaper in 100 ltr bags).

' It pays to have the same compost for like plants, so that they can be treated with the same regime of watering, feeding etc.' Could not agree more with you as having tried many different composts at the same time, watering and feeding becomes a nightmare. I now use one compost for nearly all Pleione and one compost for my Cyps.

Hope they were cheap Pleione you lost.

David

[Maren]

Thanks David,

sadly, they were yunnanensis. It hurt, a lot.

[Maggi Young]

A sad experience, Maren.  We've read before in the Forum about the use of this cat litter as a perlite substitute in compost ...... I expect you are correct in your supposition that it was the differing mixes which caused the problem by reacting in different ways to the same regime... hard lesson to learn though.

[Slug Killer]

Thanks David,

sadly, they were yunnanensis. It hurt, a lot.

Ouch!

[PDJ]

An excellent alternative I found to perlite is old plaster chunks which tend to hold more air than moisture.  Readily available free from builders when renovating houses also recommended by old gardeners for inclusion when planting clematis. 

[Maren]

The big lesson for me is not to experiment with things one doesn't want to lose.

On the bright side, the pleione harvest is turning out to be quite good. I am particularly pleased with Pln Shantung 'Pink Panther'. this is a hybrid made by a friend but he didn't like it and gave it to me. "Too girly", he said. I'm hoping to bulk it up. It looks really nice on a display stand.

[Maggi Young]

Nice flower that 'Pink Panther', Maren..... and to my eye a lot less "girly" thant some of the rather streaky violent  pinks we see 

[gote]

A rose is a rose is a rose 
But Catlitter is not catlitter
It all depends upon what it is made from.
Some are made from crushed lightweight concrete meaning that the pH is so high that it will kill nearly anything.
Some are made from some kind of clay meaning that they will turn to muck after some time. This is intentional. The result is that "wet" granules will stick together so that they can be sieved off.
Cheers
Göte

[Slug Killer]

A rose is a rose is a rose  
But Catlitter is not catlitter
It all depends upon what it is made from.
Some are made from crushed lightweight concrete meaning that the pH is so high that it will kill nearly anything.
Some are made from some kind of clay meaning that they will turn to muck after some time. This is intentional. The result is that "wet" granules will stick together so that they can be sieved off.
Cheers
Göte

And some is made from Biosorb which is moler clay similar to seramis and is perfectly OK to use. Used a lot by Bonsai growers. If in doubt which one you have bought, don't use it.

Paul Cumbleton covered this topic before for anyone who wants to read it
http://www.srgc.org.uk/wisley/2008/100908/log.html


Maren, I hope P. Pink Panther bulks up well for you as I think it's lovely.


Davis

[Luc Gilgemyn]

I agree : Pink Panther looks very nice indeed !

[Peter Maguire]

Maren,
Sorry to hear of your diasater with cat litter. But just in case people think it's totally useless, I've been trying Cypripedium seedlings this year in 50:50 Tesco cat litter (the one like moler clay) and perlite with a little (very little) leafmold added. Results so far are much better than my previous experiences growing Cyp seedlings. In this mixture in polystyrene boxes they do need regular watering (daily, via an automatic system) and feeding fortnightly.
Very little liverwort growth either.
Just have to wait 4-5 years for the flowers now. 

[gote]

Burnt moler clay will of course be quite good; No pH problem and stable. The question remains what a cat litter manufacturer will mix into it. and if he will for some reason will switch to some other substance without telling anyone. The best course would be to get it from the Danes directly. I do not use anything of this kind so I am ignorant but what are the prices on seramis, coarse perlite and cat litter respectively? If cat litter is significant cheaper than seramis, it would be a good business oppotunity to import the Danish stuff as is.
Göte

[Maren]

Hi Göte,

you've got me interested. I have been importing Seramis from Germany and it cost £450 per cubic metre, that was 5 years ago.

What's the danish stuff? where do I get it from and how much is it?

[monocotman]

Hi Maren,

sorry to hear about your experiences with cat litter.By coincidence I bought my first bag at Tesco's last week. I'd read on the web that it is used to grow Phragmipedium kovachii in the USA. I repotted a hybrid kovachii seedling into it at the weekend and will see how it fares. t was a fairly desperate case - the old compost had begun to smell and I didn't have anything else to hand.Maybe you could use up your spare litter potting up more tropical orchids?

David