Help, my pots are porous and winter is coming

Not quite what you would expect from someone firmly set in the Tropics - chuckle.

By the way it is 72 deg.F [ 22 deg.C approx. ] this morning, high may be around 90 deg.F [ 32 deg.c ] later, breezy and a mild chance of rain.

Simply put, the mix of Cement/sand / sharp sand [ casting gravel ] and pigment, at the correct consistency, lightly viibrated can be rendered water proof [ particle packing ].The exterior can be as smooth as you wish or you can work off some of it with coarse sand etc.

Now for the wintering part. There are many older Japanese books in English that show you how to. Just look'm up.

Perhaps - just perhaps, a porous pot which by the Chinese and Japanese in reading Literature, is considered the best type of pot to grow Bonsai in, would allow you Northeners to use a mix that is part organic and part inorganic, instead of the totally inorganic stuff you have to use with 1 to 3% porous Stoneware or 1% porous Porcelain ware. [ glass is 0% ]

I noted that many in the more Northern climates have no period of dry weather with low humidity, which is what my climate allows from January until April/May [ this year June ]. So the trees can rootbind in the pot in under 5 months, with no ill effects from the bucket a drop that follows as we return to the Wet season. From June until November.

So if - theory here - if you used a 5% porous pot and gave winter protection, the tree could live in a more - perhaps - natural mix.

Just sending out a few thoughts, no religion here okay.
Have a great day.
Khaimraj

hi K,

you do realise that the inorganic soil mix is only the stage straight after repotting, when the soil is 'brand new' - - - as the feed pellets added every 6 weeks break down they then supply the organic particles to the soil mix so the soil is actually becoming more and more organic as the years pass. This is why the tree gets better and better in the years after repotting.

Of course to use inorganic soils and no regular feed will not work very well, and using the inorganic soils with chemical fertilisers only often leads to long term poor results with constant deficiencies - If you want to grow like this I agree with you that organic soil could be a better option. I dont think it makes any difference how porous the pot is though - if you have good drainage and prepare the trees for winter by keeping the rain off them so they dry out properly they will be fine - a waterlogged tree that becomes frozen is the real winter problem in our hemisphere - not all species mind, some are bullet proof of course

Marcus,

I have started to use the word - compost - when speaking about the oil cake / meal balls to try and get folk to realise that they are using compost.

That, as was explained to me the pine / fir will decay into compost in the Bonsai pots, and often in under 3 to 6 months in U.S. weather.

Within the older books from Japan are tons of images on how to insulate pots / trees from winter.
Additionally trying to get folk to test those so-called Indoor Bonsai from Sub-Tropical climates and see just how Sub-Tropical they are.
Would save a good many folk from grief as they accidentally kill them.

You are an experienced grower and designer, so all of this obvious, but so many don't read / research.

With my tropical conditions, and because many of my trees are under 38 cm [ 15" ] I have to repot yearly. So only an experimental Tamarind in a clay bonded by calcium/pressure stone, is being fed on my version of organic balls.
These days a large centipede is supplying pellets, so I am working with that.
In a few more months I can tell you how it developed.

AND yes, there are also tons of images from the late 50's / 60's / 70's of Japanese folk re-potting akadama or other with the organic material from composted balls.

Thanks for reading. This was not meant to be controversial, just trying the quietest way to get folk to read.
Later.
Khaimraj