Hi there, i live in Zimbabwe and am in the process starting up a new bonsai collection. The main obstacle i am facing here is a complete lack of Bonsai resources. I am able to source tools and pots from South Africa however bringing soil across the border is complicated and expensive. The main issue for creating my own soil mix is that i have no access to Akadama, lava and pumice. I was expecting to at least be able to find pumice here but so far i have had no luck at all so i was hoping to get some advice on the best soil mix i can create with what is available to me. The mediums currently available to me are as follow:
Vermiculite
Perlite
Peat moss
Pine bark
River sand
Potting soil
Sphagnum moss
Bearing in mind that most of my trees are tropical or sub tropical could anyone recommend a good mix i could put together with whats available to me.
Are your tropicals native to Zimbabwe? If so, You might try using a mixture of what you have from your list and the native soils in which those specimens grow.
I have used perlite as a substitute for pumice, but it tends to float. Coarse river sand (ideally 2 - 6 mm), is used by some growers, and I believe is used in some areas of Japan. Based upon your list. The pine bark will hold the nutrient cations like akadama and will also be broken down by the roots. I would probably try something like 40% perlite, 40% coarse river sand, and 30% pine bark as a substitute for the 1-1-1 mix used in many places. Increase the pine bark a bit if you find this mix dries too quickly or does not support the type of growth you want.
Do you have access to farm or agriculture stores? I have used chicken grit derived from granite or flint as an additive to assist with drainage in clay soils. Do not use the oyster shell type unless you really need to raise the pH of the soil.
I find it difficult to believe there is no pumice available. Lots of volcanoes and you are an exporter of pumice. The Observatory of Economic Complexity
Check with supply stores for building and masonry. Pumice is used as an aggregate in concrete blocks. Its pores and lightness make it an excellent building substrate.
If you need to adjust the size it can be broken up to make finer grit.
Good luck with your adventure. Find others that have had success and search for any bonsai groups or clubs to find out what has worked for them.
I’ve heard of this new product showing up in The US and The UK called SAkadama, which is supposed to be a South African soil that is supposedly similar to akadama. I don’t know if that helps you, but I figure it’s somewhat closer.
