AusBonsai

Hey All,

Question about soil, i know general nurseries and bunnings etc dont have much in the way of bonsai soils, but when i've purchased a few starter plants they are in small pots with almost what you would call normal potting mix. I got a few ficus recently again, in pots, normal potting mix.

I purchased some "Scotts Osmocote professoinal bonsai mix" the other week to repot an azalea, i picked up it almost dead for a few bucks and some one said give it an emergency repot and get it going on fertilizer, so i did, in my new whooop dee doo bonsai mix. Except the "mix" had what i can only describe as a dust through it. Water literally sat on top of it, flooding the pot spilling over the sides, not a drop went in. I soaked it in a bucket for 10 minutes, pulled it out, scrapped back about 10mm, BONE DRY, the dust was literally repelling the water. Did i some how get a bad batch of soil???? Or is it that it needs to be sifted or something?

I immediately repotted it again back into normal cheapo 4$ for 20L bag of k-mart potting soil, and tossed the so called proessional mix into a dark and cold corner where it belongs. (The Azalea, how ever much looking like a skeleton has a few small buds on it now, and appears to be recovering).

So in this instance, my crappy Kmart mix was enough to bring this azalea back when "professonal bonsai mix" was a complete waste of money.

But everyone keeps going on about bonsai mix, which looks almost like a gravel, and with my experience so far im yet to see any evidence of why people make so much fuss over the right mix. Is it a mature tree thing?

Any info would be great.. cause right now i just dont get it!

CHEERS!

Just cause something is labelled "professional" does not make it any good. From what you describe of that mix it was far too full of fines. The problem that you may have with your current mix is that it will do fine up front, but in time as it rots down, it too will compact. That's the reason why most people use some form of stone/gravel/heavy grit in their mixes. Allows air in and keeps the structural integrity. Find yourself a bonsai nursery and buy from them. There is a ton of data on the web as well. Remember that plants will grow in most mixes - it's just a matter of how well they grow.

Mate all I use is equal parts quality potting mix, sand and sived crush brick then throw a hand full or two of slow release fert. Easy.

I purchased the same "Bonsai mix" and its structure was like straight peat moss (even finer). I buy a bag of clay cat litter at a supermarket and mix about half a bag of good potting mix with a bag of litter and it seems to drain quiet well. Perhaps its the kitty litter that makes my dog pull the plants out of training pots

Oh good then it wasnt just me being a newbie with that potting mix, whoo!

the sand/clay mixes sound like a win.

Thanks for the information all, ill repot them all after winter in some better mix then!

Cheers

I notice you live in Melbourne, so if you are down near Gardenworld in Springvale Road, Keysborough, they sell a good bonsai mix by the 10kg bag in their Collectors corner section. They have full time bonsai staff in their bonsai section who are happy to give advice about all matters bonsai, and their collection of bonsai are worth a look. (and no, I don't work for them)

Have a good search around the forums here.

There are plenty of good threads with good advise regarding soil mixes.
Most are pretty similar in the end and some are down to personal preference.
At the end of the day it seems a pretty common theme that dusty fines are no-good and a more open mix is best for our pots.

You can still use the "mix" you bought but from the sounds of it you will need to sift out all the super fines - then open it up with some diatomite, coarse river sand etc.

Thanks bebe, i actually brought a few of my smallers from Gardenworld, Trident maple, Japanese Maple and a Juni.. been meaning to go back but i dont pass it very often. Their range of bonsais is quite a nice walk through thats for sure!

Need to get myself a siv if im going to try use that mix, but either way would have to buy the clay litter, sand, diatomite.. something.. so it might be worth just buying a decent premix bag.

Watch out for sand, a standard bag is likely to be full of silt creating very poor drainage. If you use it make sure you rinse or sieve it well.

Only one word to remember when talking about Potting Medium - OPEN!!! Lots of grit in the mix to ensure good drainage. Now, having said that, another post here today reminded me of an experience that had me shaking my head. When I first started going up to Bali, many years ago, the guys up there were potting their Bonsai in straight garden dirt. They used to leave around an inch or so of free board from the top of the pot to the soil level, which they filled with water and it sat there until it either evaporated or soaked in - I was never sure which one I told them what I was using in Darwin at the time and even made up a bucket full of mix, something like it for them. They laughed at me and I potted one of their trees in my mix. The next time I went up, which was a few months later, the guys presented me with my tree - dead!! The open mix didn't suit the way they grew their trees.

As the general rule, potted plants do need a much more open mix than when they are grown in the ground. Anyone old enough would remember what the potting mix of old was like compared to that of today. It was heavy, compacted stuff, made up mostly of soil. Todays potting mix very rarely contain any soil at all, instead being made from compost of several types and sand/grit. It is much lighter, drains a whole lot better, holds moisture well and in the main exhibits good Cation exchange cabability. My potting medium is made from a premium quality commercial potting mix, to which I add a good serve of some form of course (2-3mm) grit. The grit I get from several different sources, from course river sand to washed crusher dust. I also use Zeolite sometimes, just depends on what I have on hand at the time, although I prefer the river sand as it is usually lighter than the other stuff.

sorry to "hijack" but i was wondering for the aggregrate/inorganic component im using some small 'pebbles' i bought in a bag from bunnings, where the label says "suitable for bonsai, aquariums, decoration". they are sized somewhere between 5-7mm. is this ok to mix in with some good potting soil? Ive read here and elsewhere about people using crushed granite, dolomite, and a bunch of other types of rocks and stuff, but im assuming this stuff should be good enough to open up the soil.

Yes anything should be OK, but the problem with 'Pebbles" is that there usually rounded and will not help the roots to split but rather have thm just grow around them
Plain gravel/ granite also does not absorb and hold moisture which is why I prefer Diatomite to Granite / Sand / Gravel.

Ken

Naimul wrote:sorry to "hijack" but i was wondering for the aggregrate/inorganic component im using some small 'pebbles' i bought in a bag from bunnings, where the label says "suitable for bonsai, aquariums, decoration". they are sized somewhere between 5-7mm. is this ok to mix in with some good potting soil? Ive read here and elsewhere about people using crushed granite, dolomite, and a bunch of other types of rocks and stuff, but im assuming this stuff should be good enough to open up the soil.

I bought the same pebbles from bunnings, and I've still yet to use them They are really only suited for decorating the top of your soil... which I found out just after purchasing them lol

There is a bit of info on the different components you can use here: https://www.ausbonsai.com.au/wiki/index.php?title=Soil

I also purchased a few bags of osmocote professional mix from Bunnings and had the same problem. Thought what the heck can i use this crap on, ended up mixing with some mix i was making for my garden bed as a bit of filler.

I have also purchased Bonsai soil from Garden world a number of times and it works ok tho they cannot tell me the composition. When asked i was told...don't know...we just buy it. I ended up adding diatomite so it did work fairly well in my ignorant opinion.

Regards
Rudy