DIY POTTING MIX INGREDIENTS

Need to source supplies to make your homemade potting mix recipe or improve a bagged mix? To make it quick and easy, most of the ingredients are available at local hardware stores (e.g. Bunnings/Mitre 10), garden centres and nurseries, horticultural suppliers and agricultural produce/animal feed stores. You can search stores online in your area. For your convenience, here is a list of a few easily available products below to accommodate different volumes and budgets. What you purchase, depends on whether you need to make a small quantity or buy in bulk. Often bulk is cheaper. Look for a “certified organic” logo on products where possible. Don’t be fooled by the word ‘organic’ used as a marketing gimmick on packaging. Some of the ingredients may have an organic or natural origin, but the product may contain chemicals if not certified. Most certified organic suppliers display the Australian ACO Bud logo which provides you with some degree of protection and confidence.

Shopping List

Potting Mix Ingredients (basics)

These are the core supplies you need to create a quality, long-lasting potting mix. Coir Peat can last up to 5 years. Vermiculite and Coarse Sand don’t degrade or shrink, so your potting mix will have great structure. Compost and worm castings are organic matter (plant food) that will decompose over time so will need replacing.

Coir Peat Block	Available from garden centres and Bunnings
Compost	Homemade or commercial eg Revitalise by Munash
Vermiculite*	Bunnings or bulk from nursery suppliers
Coarse washed river sand*	Your local landscape yard or nursery supplier
Worm Castings (Vermicast)	Try online or from a local farmer or garden group or start your own worm farm
Certified Organic Potting Mix	Purchase the best quality with Australian Standards.

 

* You can substitute these ingredients for each other, although they perform different roles.

Ideally, to save money and be more sustainable, aim to make your own compost by recycling your kitchen and garden waste rather than buying it. To save time, buy compost until you get your own bin or system started. 

Secondly, if you have space, get a worm farm and allow worms to work for you by producing rich worm castings and liquid concentrate. This is perfect plant food you can make for free. Again, the short-term solution is to buy some worm castings to start with, then aim to produce your own. Ideally, invest once in a compost system and/or warm farm with the goal to produce free resources for your garden over time. See below for options.

Another option is to buy a bagged potting mix to start with and add ingredients to improve it. All bagged soil mixes can dry out quite quickly, but you can use this as the base with which to start your garden. Add light-weight vermiculite or heavy sand for better drainage; long-lasting coir peat to hold moisture; some compost and worm castings to add organic matter. Then add the following optional nutrients to slowly feed your plants.

Nutrients & Soil Amendments

These ingredients will provide additional vital nutrients for plant health and ensure your plants have access to all the major and minor minerals and trace elements they need.

These nutrients are like a soil ‘pantry’ for your plants, to ‘self-serve’ what they need from your potting mix. By adding these nutrients, you can be confident your plants will be healthy and more resistant to pests and diseases because they are not nutrient deficient. Sick plants attract problems, that you can avoid spending more time and money on! Soil health = Plant health = Human health.

This list will give you an idea of what to look for locally. Other brands may be more easily accessible so use these as a guide for the type of product that is suitable.

 

Rock Minerals/Dust or Soft Rock Phosphate fertiliser	Available at garden centres and Bunnings
Liquid Seaweed/Kelp/Fish	Ecoseaweed | Searles range | Natrakelp | Seasol | SeaMungus
Zeolite	Available at garden centres and Bunnings
Slow release soil conditioner These are a few examples	Searles 5 in 1  | Neutrog | | Blood and bone |
Biochar	Available from nursery centres, Diggers Club
Epsom Salts	Animal/produce stores, hardware and chemists
Molasses	Try animal/produce stores (cheapest), discount chemists and supermarkets

 

Equipment and Materials (for your DIY garden supplies kit and personal protection)

 

Large Flexible Tub	Bunnings, Kmart, Officeworks and hardware stores (42L or 60L are ideal)
Small Garden Trowel & Fork	Fork and Trowel for mixing soil
Mesh Garden Sieve	Bunnings - A very handy tool for sieving chunky potting mix or compost
Gloves	Bunnings – Protect your hands from soilborne pathogens especially if you have cuts
Particulate Face Mask P1 or P2	Bunnings - Always wear a protective safety mask when making potting mix
Dust-resistant Eye Protection	Bunnings – Recommended to prevent dusty particles from damaging your eyes
Soil pH Test	Bunnings – Use to test your potting mix (aim for around 6.2-6.8 pH for most plants)

 

Compost Systems and Worm Farms

Making your own supplies is the cheapest and most sustainable option over time. Turn your food scraps and kitchen waste, grass clippings and other green garden ‘waste’ into free plant food.

Compost relies on beneficial microbes to break down this organic matter and create a rich soil to feed your plants with recycled nutrients.

Worms feed on decaying organic materials that move through their gut and come out as ‘black gold’ worm castings. Nutrients in a liquid form ready for plants to take up in the root zone.

Compost and worm castings (vermicast) are both ideal for adding to your potting and seed raising mixes for a high quality soil.

There are many options depending on your space, time and budget. These are a few to consider.

 

Compost Systems	Bunnings
Worm Farms & Live Worms	Bunnings – check online and for local worm farm suppliers

 

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