planting depth

[mark smyth]

Does anyone use these clay granules as a top dressing for winter green orchids?

[Tony Willis]

Do you kill a lot then!

yes I thought that was how to make space for new additions.

[mark smyth]

Today I went and bought a bag of Tesco's low dust clay cat litter. I wanted to see how it compares to Sophisticat

Big difference!

[Neil]

Does anyone use these clay granules as a top dressing for winter green orchids?

You don't want to use something that holds moisture near the crown.  I use 3mm Cornish grit.

[mark smyth]

Never thought of that  I must get a small sieve to get rid of fine dust in my grit

[mark smyth]

Maybe I'll sneak out the house sieve 

[mark smyth]

Here is the size difference between Tesco's low dust cat litter and Pets at Home's Sophisticat

[Steve Garvie]

You don't want to use something that holds moisture near the crown.  I use 3mm Cornish grit.

I would echo Neil.
Use of a non-angular, impervious, well-washed, quick-drying top dressing is best.
You want something that holds top growth off the moist substrate, has lots of air space between adjacent "particles" with minimal surface contact between so that there is little chance of moisture being transported up from the compost to the top growth through capillary action.

I also think that the Pets at Home baked clay is too large. I have pumice gravel of two different sizes -each similar to the two brands of cat litter -I get better results with the finer grade of pumice (but best growth of all is achieved in the Tesco cat litter composts).

[goofy]

hey,
MY experience is, that I got best results with a material
about 3mm size, which is, what I see the"left-side" material

I sieve out the Perlite  3mm, claypebbles about 3mm (here is no cat litter  like you have)
and 2-3mm coarse sand.
Thats what I use..............

cheers

[Maren]

The smaller Tesco stuff is quite nice, I use it a lot. To get rid of the dust, I don't use a sieve because that causes a lot of dust to fly around and more often than not get's in my eyes or worse my lungs. Instead, I use the same method as for perlite:

1) put the material into a large bucket
2) cover with water
3) swish around a little using my hands or a big stick
4) remove what I need with a kitchen sieve.

The dust stays behind in the water and will eventually settle on the bottom.

NB. this is also a very effective claybreaker, which I use on my allotment when breaking in a new bed.