The Great Container Mix Experiment - Part 2, Making 5-1-1

In the largest forum on the internet regarding container gardening a very active forum member Tapla is an extremely useful source of information, who has grown container plants and bonsai for a number of years.

His latest thread on the topic, which is constantly being superseded is available here. He is often around and is very generous with his advice and time.

From the thread listed above Tapla lists the ingredients for his 5-1-1 mix as;

"The 5:1:1 mix:

5 parts pine bark fines, dust - 3/8 (size is important)
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite (coarse, if you can get it)
garden lime (or gypsum in some cases) 

controlled release fertilizer (if preferred)"

Note 3/8 inch is 9.5mm. So the mix calls for dust size pine bark to 9.5mm.

I have had mixed results with this mix in the past, but am slightly suspicious that it may in fact have been something I have done wrong. I am conducting this experiment in order to work out just how much of a benefit such a mix will give compared to plain potting mix or other media such as coconut husk chips.

As the 5-1-1 mix relies on the right size pine bark to work properly, in this experiement I am mixing two batches of 5-1-1 with two different types of pine bark to give it a proper chance to perform. The mix I made previously seemed too wet and sloshy.

The Ingredients

Pine Bark

I am using two types of pine bark, both graded to the size Tapla suggests, however one tending toward the larger particles and one tending to ward the finer particles. As my problems previously were made with the smaller pine bark fines, I have made mostly larger grade mix, with a single comparison with the finer pine bark for comparison.

Fine Pine Bark

Larger Pine Bark Pieces (most under 10mm)

Here is an indication on their differences in size.

Coarse VS Fine VS Perlite

Perlite

Perlite is a type of volcanic glass that occurs when certain minerals are heated to a certain temperature. It is very light and white and resembles the beans from a bean bag. Perlite is my top contender to why my previous 5-1-1 mix was so wet, as the perlite purchased from Bunnings is very fine. For this experiment I have tracked down a big 100L bag of coarse perlite, which can be found online or your local hydroponic store for around $50. 

Coarse Grade Perlite

Sphagnum Peat Moss

Sphagnum moss is the dead and decayed sphagnum plants that grow in peat bogs around the world. Care should be taken to find a source of peat that is sourced from renewable bogs. I found mine at a local nursery, and it wasn't particularly cheap at around  $80 for the bag below.

Sphagnum Peat Moss 

Mixing the 5-1-1

Mixing up 5-1-1 is very easy, simply 5 parts pine bark, 1 part peat and 1 part perlite. I start by using a wheelbarrow and a 8L pot.

First I measure out five pots worth of pine bark fines and add them to the wheelbarrow.

'Fine' Pine Bark Fines

'Coarse' Pine Bark Fines

Next add one pot worth of perlite

'Fine' Pine Bark

'Coarse' Pine Bark

Next I give it a mix through and then add one pot full of peat.

'Fine' Pine Bark

'Coarse' Pine Bark

Finally, the recipe calls for the additional of dolomitic lime. I added one handful, and one handful of slow release Osmocote fertiliser. I also added two handfuls of organic Dynamic Lifter.

Adding Dolomitic Lime and Osmocote

It is important to wet this mixture well after mixing, as peat moss and pine bark are quite hydrophobic when dry. When I wet this mixtures they both turned to a similar mud-like consistency.

'Fine' 5-1-1

'Coarse' 5-1-1

I then potted up the mix into its pots ready for the experiment. Below is my rows of course and fine 5-1-1 ready to go, as well as the pots of plain potting mix (with added dolomitic lime, osmocote and Dynamic Lifter for consistency). 

Three pots of 'Coarse' and one pot of 'fine' 5-1-1. Potting mix in the centre. 

Next post will be making the coconut husk mix, which kind of has a bit of everything in it. Just waiting on the main ingredient to be delivered!