What Is Potting Mix?
The Difference Is in the Mix
If youāve used a cheap potting mix and your plants havenāt thrived, itās not you ā itās the mix. Compare budget blends with premium, highāperformance mixes trusted by Aussie gardeners and see the difference quality makes.
| CHEAP POTTING MIX | PREMIUM POTTING MIX |
|---|---|
| ā Often made from lowāquality or uncomposted materials such as wood shavings, sawdust and sand. | ā Made from highāquality raw materials for reliable plant performance. |
| ā Has poor texture and structure, offering little nutritional value for plants. | ā Maintains structure for up to two years without compacting or slumping. |
| ā May have an unsuitable low pH, making it difficult for many plants to thrive. | ā Fully composted to reduce the risk of weeds, pests and diseases. |
| ā Contains no controlledārelease fertiliser to support ongoing growth. | ā Provides excellent structure and air porosity so roots can access essential oxygen. |
| ā Breaks down and slumps in the pot within months, reducing airflow to roots. | ā Includes controlledārelease fertiliser to feed plants for several months. |
| ā Provides poor aeration, which can starve roots of oxygen. | ā Contains a professionalāgrade wetting agent for better moisture penetration and retention. |
| ā Lacks wetting agents or waterāstoring crystals, making it difficult to reāwet once dry. | ā Offers good drainage while still holding the moisture plants need. |
| ā Does not meet the relevant Australian Standard for growing media. | ā Has an ideal pH range of 5.9ā6.2, suitable for most plant types. |
QUALITY POTTING MIX INGREDIENTS
Australian potting mixes are recognised as some of the best in the world. Thatās because leading brands like Scotts Osmocote is made from highāquality raw materials, and every finished product meets the Australian Standard for growing media.
Our premium and superior potting mixes are crafted from:
- Composted pine bark ā a renewable, sustainable material that creates structure and supports healthy roots.
- Coarse sand or grit ā to improve aeration and drainage.
- Coir fibre ā a renewable resource that holds moisture and nutrients while keeping mixes light.
- Wetting agent ā to improve moisture penetration and retention, ensuring even watering.
- Controlledārelease fertiliser ā feeding plants for months, not days.
Some mixes may also include perlite or vermiculite to keep the mix lighter ā ideal for large tubs, vertical gardens or rooftop spaces where weight matters.
Perlite is a naturally occurring, nonācrystalline mineral that expands dramatically when heated, creating a lightweight material that boosts aeration. Vermiculite is formed from natural minerals that exfoliate into a light, flaky material when heated, helping hold moisture and nutrients.
Why Garden Soil Doesnāt Belong in Pots
Many people assume you can scoop up a bit of garden soil and use it in a pot ā but pots work very differently to the open ground.
In the garden, plant roots have endless space to spread out in search of nutrients, water and air. But in a pot, roots are confined, so they rely completely on the quality of the mix around them. Thatās why using garden soil in a container almost always leads to poor results.
EXAMAPLE = Filling a standard 180mm pot with soil straight from your garden:
- Contains almost no available nutrients
- Will not absorb or hold water well
- Is poorly aerated, causing roots to suffocate
Plants grown this way will struggle to survive.
EXAMAPLE = Filling the same pot with premium potting mix:
- Contains added fertiliser
- Is well aerated
- Includes coir or organic matter to hold moisture and nutrients
The difference in plant health and growth is dramatic.
POTTING MIX VS SOIL
Thinking of using garden soil in pots? Hereās why potting mix delivers better results.
| GARDEN SOIL | POTTING MIX |
|---|---|
| ā Contains very little usable nutrient | ā Includes longāterm fertiliser for sustained feeding |
| ā Holds minimal moisture | ā Contains coir and/or wetting agent for better water holding |
| ā Becomes compacted and poorly aerated | ā Uses graded bark particles for healthy aeration |
| ā Can set hard when dry, blocking root growth | ā Has a mix of particle sizes that prevents ācakingā |
| ā Naturally low in organic matter | ā Made from composted, organicārich ingredients |
WHAT GOES INTO OUR QUALITY POTTING MIX?
Highāquality potting mix starts with highāquality ingredients ā and for us, that begins with composted pine bark. Sourced locally from the Australian plantation timber industry, itās renewable, sustainable and forms the foundation of our premium blends.
Transforming raw bark into a superior potting mix involves a carefully controlled process:
- Milling and screening the bark to create the ideal particle sizes for different mixes.
- Blending with base fertilisers to initiate composting.
- Forming long windrows outdoors, allowing the bark to break down naturally.
- Turning the rows regularly for even composting.
- Reaching temperatures around 60Ā°C, which naturally suppress weeds and harmful pathogens.
After two to three months, once the bark is fully composted and stable, we add the ingredients that define each mix ā including coir, sand, wetting agent and controlledārelease fertiliser. Every formulation is crafted to meet the unique needs for Scotts Osmocote.
Finally, each blend is bagged, palletised and delivered fresh to retail stores so you get the very best mix, every time.
