Potting Mix vs Garden Soil vs Soil Improver... What’s the difference?

With the wide variety of growing mediums available to gardeners it can sometimes be confusing knowing what to use, and what the difference is between products.  If you’ve ever looked into a bag of soil, potting mix and soil improver and thought “they’re all brown, and they all look like soil!” then you’re not alone. 

Before deciding if you need garden soil, potting mix or a soil improver, you should ask yourself 3 key questions: 

1. Where will the growing medium be used?  
   Do I need to fill a new or existing garden bed (outdoor garden beds or raised garden beds)?
   Am I planting into containers such as pots, planter boxes or hanging baskets? 
2. How much is required?
   Do I need a truck load or just a few bags?
3. What plants do I want to grow?
   Am I planning to grow veggies or other specific ornamentals? 

In general, the main differences between potting mix, garden soil and soil improvers relate to their drainage qualities (air is good!), water retention characteristics and the amount of organic material and nutrients. 

Potting Mix

Potting mix, as the name suggests, is generally more suitable when growing plants in pots and other containers.  Rocky Point’s Coco Pro and Premium Potting Mix are an ideal choice when potting a wide variety of plants. Both provide a light, nutrient and fertiliser-rich, free-draining growing medium, with good water-holding capacity due to the addition of coir chip.  Potting mixes can provide a good balance of moisture retention and adequate aeration that is all important when it comes to potted plants.

Some Potting Mix products such as Grow More Premium Potting Mix come with a higher proportion of organic matter, and added nutrients in the form of slow-release fertilisers and trace elements to feed and nourish your plants. 

Garden Soil

Garden soil, on the other hand, lends itself to more of the larger scale garden beds, where a larger quantity is usually required.  For existing gardens where you may want to top up and replenish the soil, Rocky Point’s Good to Grow Garden Soil is a convenient option or if you are looking for richer soil try our latest addition Organic Health Garden Soil.

Soil consists of weathered minerals – sand, silt and clay, and organic matter (humus); and these components vary according to the soil type. Soils are usually heavier and more dense compared to potting mix, and the organic material forms an integral part of the soil food web (think beneficial bacteria, fungi and worms). 

Garden soil should not be used as a potting medium because it generally lacks the drainage, aeration and nutrients required for container plants.  It may be possible to make your own blend of garden soil suitable for pots, but who has time for that? 

Soil Improver

Soil improvers pretty much do what they say – they improve the quality of the soil. Garden soil in an existing garden can benefit with the addition of a good quality soil improver like ActivGrow Soil Improver, and will reinvigorate your tired garden beds and replenish the nutrients that plants need.    If you are looking to enrich the soil you could also use some other soil improvers and amendments, depending on what you are growing and the specific requirements of your plants; these include: 

• Rocky Point’s Cow Manure Plus – chock full of beneficial microbes 
• Rocky Point’s ActivGrow Fertiliser Pellets – for a fast boost of concentrated goodness 
• Rocky Point’s Sugar Cane Mulch – to lock in moisture and add organic matter 
• Compost 
• Perlite or Vermiculite 
• Other amendments, including lime, sulphur and gypsum 

There you have it – all the earthy stuff explained!