AusBonsai

Time for me to switch from soil to a modern substrate when repotting season hits. My big concern is that i have a 1 year old and the backyard is his as much as mine. He has a habit of sticking his hand in the bonsai pots (annoying I know, but he's 1). My concern is that some of the modern substrates (diatomite, purlite, maybe more) are dangerous to breathe. I'm not really comfortable to use them if that's the case. Anyone know a good, but safe mix. Here's an idea:

50% Zeolite
30% Polystyrene balls (bean bag filling)
20% spag

You saw Polystrene and did this right? I actually got this idea from Walter Pall's article on substrates. And besides their weight, they fit the criteria for a modern substrate. I figure combining with Zeolite could help the weight issue. Top dressing with a layer of zeolite or gravel might do it too. What do you think?

The dust is the issue and after a couple of waterings the mix is pretty much dustless.

DustyRusty wrote:Time for me to switch from soil to a modern substrate when repotting season hits. My big concern is that i have a 1 year old and the backyard is his as much as mine. He has a habit of sticking his hand in the bonsai pots (annoying I know, but he's 1). My concern is that some of the modern substrates (diatomite, purlite, maybe more) are dangerous to breathe. I'm not really comfortable to use them if that's the case. Anyone know a good, but safe mix. Here's an idea:

50% Zeolite
30% Polystyrene balls (bean bag filling)
20% spag

You saw Polystrene and did this right? I actually got this idea from Walter Pall's article on substrates. And besides their weight, they fit the criteria for a modern substrate. I figure combining with Zeolite could help the weight issue. Top dressing with a layer of zeolite or gravel might do it too. What do you think?

Hi DustyRusty,
If you use a mix like this you will have to watch your watering very closely. The pots may tend to dry quickly. If you top dressed the pots I would use the zeolite, not the gravel. Zeolite will help to hold the water. The other issue is the lack of food in this mix. You will have to have a good feeding regime.

Could you fence off or lift the bonsai so the little one can't get to the pots?

Regards Ray

Jow wrote:The dust is the issue and after a couple of waterings the mix is pretty much dustless.

I use diatomite. When I bring it home, I make sure the kids are inside, put it in a big bucket with a screen on the bottom and run water through it until it runs clear. After that, there really isn't any dust left. If I store it before using it, I rinse again before using, and then after potting.

For what it's worth, I've heard the rinse water that has all the dust in it makes a great mechanical pesticide - cuts right through bugs' shells and they die.

Thanks for the thoughts.

Sounds like diatomite is safe once it's rinsed. That's what I needed to know. I'll make sure I buy the right sieving tools before I go ahead. Thanks for your feedback on the mix Ray. I was hoping the spag might solve the water retention issue, but sounds like i may need a bit more than that if i went with it. I think i'll probably use a diatomite/zeolite/spag mix after what the others have said anyway. No probs about heavy regular feeding/watering, gives me something to do with the trees each day. Not easy to fence off the bonsai bit. I have probably 20 nursery pots with collected stuff and cuttings. My place is too small for one whole section for this, so they're spread everywhere (the wife hates it).

Thanks for thoughts again.

Nick

DustyRusty wrote: I have probably 20 nursery pots with collected stuff and cuttings. My place is too small for one whole section for this, so they're spread everywhere (the wife hates it).

Gee that sounds familiar . . . I think this is how you know it's time to join a support group. Like this one.

You saw Polystrene and did this right? I actually got this idea from Walter Pall's article on substrates. And besides their weight, they fit the criteria for a modern substrate. I figure combining with Zeolite could help the weight issue. Top dressing with a layer of zeolite or gravel might do it too. What do you think?[/quote]

I worked in a wholesale nursery as a teen and the entire nursery stock was potted up with polystyrene balls in the mix! Although I haven't heard of people using it since!

Yeah I potted up a callistemon tubestock a couple of months ago that had the root ball covered in polystyrene balls. It took me aback, as I'd never seen them used before. Unfortunately he didn't survive in the end

I just loaded up on a heap of pumice, so will test that out, probably with zeolite, next potting season... I think pumice (when the dust is off it) should be pretty safe...

DustyRusty, polystyrene balls will give you pore space in the mix and of course make the soil light, but they don't provide any water holding capacity or any capacity for aiding root division. From a safety perspective, they would be a pretty nasty choking hazard for a little kid as they are easily inhaled.

Cheers,
Mojo

Mojo Moyogi wrote:DustyRusty, polystyrene balls will give you pore space in the mix and of course make the soil light, but they don't provide any water holding capacity or any capacity for aiding root division. From a safety perspective, they would be a pretty nasty choking hazard for a little kid as they are easily inhaled.

Cheers,
Mojo

I agree.
Ditaomite, Zelolite, Pumice and if you want some chopped Spag or Peat moss.
Rinse it a you are gold.

Poly balls apart from being made from Chemicals and not natural will be a no no for me.

Hey Ray, Any modern substrate will have to be fertilised well, but the way I see it, how much nutrients would be in an organic mix after it has been rinsed and flooded daily for a month or so like we do? I would reckon that a tree in Organic mix, will still require as much fert over a year as one in a Subtrate.
Have no idea really except I do not fert as often as I should due to work and my trees seem be OK.

Ken

Just did a bit of reading on the use of Sphagnum moss in potting mix and found the following, which may be of interest to you,

(Quote), "Sphagnum moss can potentially harbour the fungi causing the chronic disease sporotrichosis.[35] Sporothrix schenckii spores enter the skin via abrasions, scratches, and small puncture wounds as a result of unprotected contact exposure to Sphagnum moss". (End Quote). Source Wikepedia.

Interesting when considering your search for a "Safe" potting medium. Potting is usually a very safe pasttime, if you follow a few simple 'rules'. First off, moist potting medium is usually 99% safe. It is mostly when handleing dry medium we risk health issues. Therefore, your little tacker sticking his hands in a potted up, pot of potting medium runs a very small risk of getting anything other than dirty hands. That is not to say there is no risk, but the risk would be so small you probably really shouldn't worry about them. Even your 'ideal mix' of 50% Zeolite, 30% Polystyrene balls (bean bag filling) and 20% spag contains a fairly significant risk, if allowed to dry out (which it wouldn't, as the plant would be at risk of dieing). The Sphag' risk has been covered, as has the styrene ball risk. The risk from Zeolite comes in the form of Silica, which we all know is fairly bad stuff to be breathing in. While the silica levels are not high, they do still exist and how many of us wear a mask when sieving the stuff? Organic components in potting media expose us to Legionaires Disease so that is risky, but the risk is manageable IF we simply observe a few proceedures when mixing our media and while potting up. After those two proceedures are completed the risks are further reduced to the point where they are not really worth dwelling on. Unless of course the nipper takes a feed of fertilizer pellets from the top of the pot, then the risk factor starts all over again.

Golden rule where potting medium is concern, as has been said before, never work with the stuff when it is dry unless you are wearing a mask - and always remember to wash your hands properly when potting is finished for the day, before eating or drinking or having a smoke. Never wipe your dirty hands across your mouth or face as well.

By the way, instead of styrene balls have you thought about Vermiculite? The only problem I could see with your suggested potting medium is the lack of buffering in the mix. As I do not know where you live this may not be a problem, but I would be a bit concerned about it anyway, especially when you start potting your trees out of the black plastics and into Bonsai pots.

Probably the easiest way to reduce the young blokes risk is to put in a few shelves and put your trees up out of reach, but of course then you have the added risk of him pulling a pot down on top of him I guess.

I think I would worry more about inhaling silica. Sporothrix or Legionaires disease are both pretty rare, but inhaling silica will definitely cause problems if you inhale enough of it.

Just to put it in perspective though, driving is much more dangerous and most of us do that quite a bit. Still, good on you for keeping an eye out for the little one.

Thanks for the replies and thoughts everyone.

Mojo, it's not true that polystyrene balls don't have a water holding capacity. They do. Polystyrene is porous much like perlite (although probably not as good). Choking wise i'll have to disagree too. a polystyrene ball is the size of a pin head. This is too small to be a serious choking risk.

Ken, i really value your thoughts. Although I have a philosophical disagreement with the 'not natural' thing. Chemicals occur naturally. And if you really want to take the 'natural' horticulture to it's logical end, then you shouldn't be planting your trees in the remains of ancient sea creatures. It's not natural for trees to grow in that substance. I believe that human ingenuity can actually provide better conditions than nature can provide for plants, to a degree.

Graeme, thanks for that info on spag, i didn't know that!

To all, thank you. I ended up doing a reshuffle over the weekend and managed to get my trees up about two more feet. Impossible for the boy to touch and the added bonus is they get about an hour and a half more sunlight

I'll take all your advice and repot when the season comes with diatomite, zeolite and spag, making sure i sift all the dust particles out, rinse well, and keep them wet.

Thanks again,

Dusty