Not sure how much potting mix you need to fill your new pot? We've got you covered! Here's a handy table of common standard nursery pot sizes available from your local Flower Power Garden Centre and how much potting mix you'll need to fill them up.

 

Pot diameter (cm / mm)

Potting mix volume required (L)

How many 25L bags?

How many 30L bags?

14cm / 140mm

 1.5 Litres 1 bag fills 16 pots 1 bag fills 20 pots

18cm / 180mm

 3.3 Litres 1 bag fills 7.5 pots 1 bag fills 9 pots

20cm / 200mm

 4.5 Litres 1 bag fills 5.5 pots 1 bag fills 6.5 pots

25cm / 250mm

 8.5 Litres 1 bag fills 2.9 pots 1 bag fills 3.5 pots

30cm / 300mm

 14.5 Litres 1 bag fills 1.7 pots 1 bag fills 2 pots

40cm / 400mm

 27 litres 2 bags 1 bag

50cm / 500mm

 52 Litres 3 bags 2 bags

Half Wine Barrel

 90-120 Litres 4-5 bags 3-4 bags

All figures listed above are approximate and are based on standard-sized nursery pots with the pot rim diameters listed above. Capacity may vary based on quality and compaction of the mix and size of the root ball of the plant. 

 

Which potting mix is right for me?

Good question - and the answer depends on your plants! For the best possible results we always recommend a mix that meets the Australian Standard for premium potting mixes - look for the red ticks on the bag. This means it's fully composted, free from contaminants and filled with enough slow-release fertiliser to sustain happy, healthy plants for a number of months. Supersoil Professional Potting Mix is our all-purpose hero, and works for most plants. However, if you're growing plants with specialised growing media needs, such as orchids, natives, roses, camellias or edibles, consider a specialty potting mix that's tailored to your plant. Our Supersoil Professional range covers all these needs and more.

 

Why can't I just use soil?

Potting mix is a specialty product that's designed for superior performance in containers. Soil, while great in garden beds where roots have lots of space to expand, simply doesn't work well in pots - it tends to get clumpy and inhibit drainage, leading to unhappy plants. Click here for the full run-down from garden expert Jennifer Stackhouse.