Andrew’s soil mix

I always seem to be banging on about soil. The reason is that poor soil, more precisely poorly draining soil, is usually at the heart of problems with growing plants. Most plants die as a result of being overwatered, and I’d suggest that this is very much true of bonsai.

If the least you can do is add coarse perlite to a top quality potting medium, then you’ll be doing your plants an enormous favour. Sure, you’ll have to deal with the issue of the perlite ‘floating’ about on top of your soil, but most of the perlite will be under the soil surface and providing more air to the roots of your plants. Don’t be mean with your perlite either – I’d recommend about 30% perlite added to a top quality potting mix.

Use caution when handling perlite. I buy it in a 100 litre bag from the hydro shop – get super coarse (I find the others are too fine). Open the bag out in the open and wet the contents down, really  wet it down so as to reduce perlite dust. I’d recommend wearing a dust mask too as an extra precaution from breathing the perlite dust in.

If you want to make a much more open mix, then this is my current recipe…

2 parts coco orchid mix

1 part 7 – 20 mm pumice

1 part LECA (clay hydro balls)

1 part scoria (you can buy in bulk from Garden Proud but need to sieve the fine dust out of it) 

1 part super coarse perlite

1/2 part bio char

1 and 1/2 parts AusGro Orchid Bark Minis

2 cups Zeolite

1 cup Trophorte slow release fertiliser (it has beneficial microbes and is slow release like Osmocote or Nutricote but the colour is brown and not some ghastly bright mustard)

My plants have been doing very well in this mix, I use it for all my potted plants, whether they be bonsai, succulents, cacti, bulbs, ferns, bromeliads or aroids and growth is strong. In our 40c mini heat wave I was watering every morning really well (water would be soaked into the pots until it was running through the pots) but that was it until the next day. My plants thrived through the heat.

I don’t add Rapid Raiser or Sudden Impact for Roses to this basic mix, not even any Blood and Bone. I don’t want to supercharge the nutrient level too much. You can always use these, and other products at a later time with your regular fertilising program. I let the Trophorte provide the nutrient to get the plants settled, knowing that it is a true slow release fertiliser.

Remember to access the special deals available from Neutrog for club members. These are terrific products and available at greatly discounted prices to our members. You order and pay online through Neutrog’s website and set where you will collect your order.  The next order collection is mid-May and cut off is usually a couple of weeks earlier. If you don’t have access to the Neutrog Members’ Store then please contact Annie to arrange access for you. 

Andrew Ward

Nationally Registered Bonsai Artist and Demonstrator – Association of Australian Bonsai Clubs

Treasurer – Bonsai Federation of Australia (Southern)

2023 Bonsai Show