Washing out the dust

Ok, so I know that sifting out the dust and fine particles is a good idea, and I have done that to avoid slug building up in the bottom of my containers. But, there is something I'm curious about. I hear a lot of people talking about washing the excess dust off of the substrate, and I'm wondering if it is worth the extra effort. So far, I've been using material such as diatomite, turface and pearlite in different mixes. After I sift them down to about and 1/8th of an inch, there doesn't appear to be much dust. What remains would seem to be just residual. Furthermore, most of my trees are getting planted in cheap dollar store colanders, which offer great drainage and don't really provide much of an area for dust to build up.

That being said, I'd like some opinions. Do you wash out you soil, and do you think it is an important part of the long term health of a plant?

I use mostly lava and I never wash the dust out. I Know a lot of people do. When I repot, I do not have any sludge in the bottom of the pot. If your mix is free draining, it will get rinsed every time you water. I don't sift any of my componets either, unless I need some smaller particles for a Shohin or Mame size tree. Could be that I am just lazy, but I have not had a tree suffer from it.

Hello,
I wash my diatomite because when it comes in the bag, the dust contains nano particles.
So not that good when it gets into your lungs.
The brand i use is perfumed as it is used as cat litter, the washing in a big bin, will remove the smell as well.
There is a horticultural brand without perfume, strangely enough this one cost more.
Sunip

If, while you are sifting, you hold the strainer a bit up over the container you are sifting into, any breeze usually winnows out the major part of the dust.

Out of all of the substrate ingredients I've used, the only one that seems to need washing is pumice. Scoria, turface, diatomite, etc. all have very fine dust that easily washes out in the first couple of waterings. Pumice, on the other hand, leaves behind a silty residue that can clog your container, if used as more than about 30% of your mix.

sunip wrote:Hello,
I wash my diatomite because when it comes in the bag, the dust contains nano particles.
So not that good when it gets into your lungs.
The brand i use is perfumed as it is used as cat litter, the washing in a big bin, will remove the smell as well.
There is a horticultural brand without perfume, strangely enough this one cost more.
Sunip

The, diatomite I'm using comes from Napa auto parts, and is used as an absorbent for spills. So far, it's the best soil component that I have been able to find. I bought some Turface from a local John deer supplier, but all they had was Allsport, which upon further consideration seems to be on the fine side. I don't think it will cause problems, as most of the material I'm working with is freshly collected, and would probably benefit from a finer soil. But the diatomite seems like a better option at the moment.

and jim, I did notice what you were talking about. I sifted on a windy day and it seemed like a good bit of dust was blowing out of the diatomite.

Stan Kengai wrote:Out of all of the substrate ingredients I've used, the only one that seems to need washing is pumice. Scoria, turface, diatomite, etc. all have very fine dust that easily washes out in the first couple of waterings. Pumice, on the other hand, leaves behind a silty residue that can clog your container, if used as more than about 30% of your mix.

i second this...i use a lot of pumice because it is cheap and available in my area, and have found the same problem...even after sifting it seems like every piece of pumice has dust on it that turns to a very fine silty substance when rinsed...seriously, you would be amazed at how much runs out when you rinse it...