I recently purchased a large amount of beautiful rock from Smith and Hawken. They are ritzy gardening store that would not be discussed here usually BUT they are going out of business so everything there is dirt cheap right now. If you have one in your area it's worth taking the trip! Their gravel bins are reduced to .99 cents a lb from 4.99$ a lb. I bought a couple of types, avery nice green/grey color and deep purple, perfect size for use in bonsai soil(just smaller that a pea).

What I'm looking for opinion on is this...

When it comes time to repot your trees could the rock portion of soil be cleaned off and reused? Once dried out It would be easy enough to separate the rock from the old clay and what was left of the pine bark but iwould it be safe to be used again?

Any gravel that is dyed would never be introduced in my substrate. When it comes to recycling, the only place my old soil finds its way is into my growing beds. Too much time and effort are spent on our trees, I simply don't skimp on soil, neither should you.

I agree with Rick about dyed stones. I simply wouldn't take the chance.

If they're undyed, that's good. But are they sharp-edged, or rounded? Sharp-edged tend to give better drainage (as a general rule) and promote root branching: a rootlet scrapes itself and (frequently) responds to the trauma by branching.

Thanks for the reply I think, but I think Rick misunderstood the question. The stones are not dyed. If any one is looking to take advantage of the store's deal they are all natural, 100% safe for any garden!!! They're kept in the back of the store right below the hand made japanese folding saws and shears as a marker for ya if you walkin with your nose that high in the air. As I said it's Scarsdale NY, a place where the average property taxes dwarf what middle class america bring in a year....

I was looking for an answer dealing more with if there is any thing on a cellular level that accumulates over the years. I know certain blight will remain for a long time once it there but I'm not sure if it will survive on the rock. Or even better if there are other places to get high quality grit at such a low price so it's not worth the trouble to even bother.

But Treebeard the grey/green stones are on the smother side but there are some jagged ones in the mix and the purple are on the sharper side for the most part. They did have a bin of sharp black and white granite but it was 2.50$ a lb. Also the greyish ones were more like the rocks in the soil that was used at this bonsai nursery in Connecticut I went to last spring for a master class with Invernizzi. That which does not please the eye first can not with hold the heart.

Er, even at $.99 a pound, I'd give it a pass for general use... I recently picked up 150 pounds of hen grit for about $35-$40 at the local feed store. Total. This is non-reactive, crushed quartzite stuff that is the right size, is rough, and works with nothing more than a rinse to get the powder out. No sifting, nada. The color is a bit odd, sort of a pinkish, but that's what moss is for.

And yes, soil components will retain microbes, insect larvae/eggs and built up salts unless you want to take the time to boil the stuff. So if your plants are healthy, you might think about reusing after a good rinse, but... really... the grit will build up a bio film of organic material that is living on the surface. Some of the things growing on there will be beneficial, others not, but mostly its going to be stuff that is just gonna clog up the surface and eventually die and rot. And as far as reusing the 'rock portion' are you going to be sitting around picking this stuff out by hand? Ummmm, have fun.

Besides, why buy fancy expensive decorative grit for general use? You are going to see maybe 1/100th of it if you use it in your mix, so save it for a top dressing for shows, if you're not using moss.

Anthony,

I am having a hard time following your train of thought, not just on this thread but some other posts as well. This is under frugal bonsai. I purchase crushed granite for gravel, $8.99/50 lbs bag and I get to choose the size I want from 1/16 - 3/8 of an inch.

Why stress yourself if you don't follow but maybe this will help clarify-

The hen grit, 150 lbs - 40$ or crushed gravel 8.99$ - 50 lbs both much cheaper then what I found and as weeble said not wasting nice stuff that you wont see. Both replies offer a cheaper more efficient way to get grit for your mix. hence the title FRUGAL Bonsaist. Also anyone who read this can get that info at a glance and hopefully add more good ideas to it.

If this is your belief -
"Too much time and effort are spent on our trees, I simply don't skimp on soil, neither should you."
Then why read here? If it doesn't apply, let it fly

Anthony, to try to answer your clarified question: it depends on the porosity of the kind of rock used. Some rock holds a lot of water, and therefore will build up deposits of soluble material over time; easy examples are pumice and sandstone. At the other end of the range are metamorphic rocks like marble that absorb such small amounts that, for the purposes of your question, they can be considered impervious. Minute amounts of foreign material will adhere to the surface, but not much, in my opinion.

I used crushed granite also, sold for poultry grit; around here it can be gotten in several sizes and several natural colors. I'd see no reason not to re-use it a few times, ceteras parabus. But Weeble raised a valid practical point: the rock would have be separated out if one wished to re-use it but not the rest of the mix. And for me, that simply wouldn't be worth the time and effort involved; it would be cheaper and less time-consuming to sift fresh grit and use it.

Thanks treebeard btw I think your name and pic are the best on the site!

You're welcome.

As for the name, my siblings started calling me "the ent" many years ago, because of my interest in "little trees." The username followed logically.

The avatar pic was taken by my 9-year-old daughter last spring, shooting out thru the car window while I tried to put on a mock-scary face for her. If it's scary enough, I'll refine and perfect it for when she starts to date!