AusBonsai

Hi All,

I am getting back into bonsai after a few years of not having time/motivation etc. A LOT of my trees didn't make it due to lack of care/watering, so I am forced to begin again, with the exception of a few trees who's roots were able to escape their pots into the ground.

My plan is to use a good quality potting mix in black plastic grow pots for the first few years until I have something that is displayable.
I'll be using the Searles Premium Advanced Potting Mix, 65ltr for $22.55.
I'd like to add some zeolite to the mix for a few reasons, to make it go further, increase drainage to prevent root rot etc.

I have a zeolite mine within an hour's drive from home, and they offer a few different sizes, the two I think would be most suitable would be either 1-2mm, or 2-4mm.

Would one of these be considered the 'best' size?

And how much should I look to add into a 65ltr bag of the above commercial mix?

Again, this is purely for black plastic pot growing of young trees and pre-bonsai stock, not refined stock going into a small bonsai pot.

Many thanks, in advance,
Steve.

you cant go wrong with either of those sizes really. Add 10% zeolite : 90% mix, the main benefit of zeolite is its cation exchange capacity CEC which helps holds nutrients for the plants to use rather than them going down the drain. Also I'd recommend Scoria as a good relatively cheap potting mix additive, just test each batch as it can be highly alkaline. Also hydroponics shops are great for all sorts of mix additives such as perlite, coir,etc
good luck

Personally id go the bigger size 2-4mm to improve drainage and air exchange etc.

I add 20% zeolite ot my own Akadama, Pumice Zeolite mix.
1-7mm pumice, 2-6mm Akadama and 2-6mm Zeolite

Ken

Thanks guys.

There's also two zeolites you can generally find:

- one is that pinky colour and comes in large sacks - I've found this stuff is quite hard and will last a long time in a mix before breaking down.
- the other, is the cat litter from Woolworths - this used to have really good distribution (and was cheap) - but have found it can be hit and miss these days. This stuff breaks down over a shorter period and I've found it also absorbs more water. It's actually surprisingly good stuff if you can get lucky and not end up with a bag of powder.

Oli

Thanks Oli,

Yeah I bought the cat litter today, the Smitten brand one, as Woolworths no longer stocks their orange bag own brand one by the looks. Seems like it 'might' not last more than a single repot, maybe 2 years, but I'll try it regardless.

The zeolite mine nearby will have the pink stuff, but don't currently have the right size, only the smaller stuff, which I found out is 1-3mm, not 1-2mm, but still maybe a little small. They do list it as a potting mix additive, so might be ok if that's all they have at the time when I am able to get to them.

Thanks again,
Steve.

I’ve been trying the Smitten brand since last year. Only 12 months in, but seems to have held up well, from what I’ve seen during repotting so far. Little break down, no unexpected tree losses. I used my widest-bore sieve, so only 3-4mm diameter particles and above have been used.
Wear a mask, I suggest. I can’t imagine that inhaling mineral dust while sieving will be good for your lungs in 20 years.