Potting Mixes, Mulches & Fertilisers

Choosing the right mix

Bagged products are not interchangeable. Potting mix is engineered to drain and hold air inside a container, so it is the only thing that belongs in a pot; garden soil in a pot sets like concrete. In the ground the roles reverse: composts and manures improve the soil you already have, and bagged garden soil bulks up new beds. The speciality mixes matter more than they look. Native mixes such as Scotts Osmocote Native run low phosphorus to suit banksias, grevilleas and most Australian natives, citrus mixes feed harder for hungry fruiting trees, and orchid and succulent mixes are built around fast drainage above all else. If in doubt, a premium all purpose potting mix with controlled release fertiliser already in it covers everything else.

How much potting mix, mulch and manure to buy

• Pots. A 20cm pot takes about 5L of mix, a 30cm pot about 15L, and a 40cm pot about 30L. One 25L bag fills a 35cm pot with some left over, and a 50L bag handles a large tub.
• Mulch. At the recommended 75mm depth, one 70L bag covers about one square metre and a 25L bag roughly a third of that. Measure the bed and round up.
• Manure and compost. Spread 25L over about half a square metre, fork it through, then rest the bed for two weeks before planting.
• Clay breakers. Gypsum goes on at around 1kg per square metre for heavy clay. Follow the bag rate and water it in.

Feeding through the year

Two applications of a controlled release fertiliser, one in early spring and one in late summer, carry most gardens. Use a native specific fertiliser like Neutrog Bush Tucker for phosphorus sensitive plants, and sulphate of potash in late spring where flowers or fruit matter more than leaves. Liquid seaweed is a tonic rather than a feed: applied fortnightly it helps new plantings establish and stressed plants recover, but it does not replace fertiliser. Indoor plants prefer little and often, which is where the pour and feed or mist bottles beat granules.

If you are setting up for a full planting weekend, the garden tools and accessories range and pest control products cover the rest of the job, and the pots and planters collection has sizes to match every bag of mix on this page.

Common questions

Can I use garden soil in pots?

No. It compacts, suffocates roots and breeds fungus gnats indoors. Use potting mix in every container, and keep the garden soil and compost products for building up beds.

Which products suit native plants?

Low phosphorus is the rule: a native potting mix in containers and a native formulated fertiliser in the ground. Standard composts and mulches are fine around most established natives.

Does mulch really need to be 75mm deep?

Close to it. Under 50mm, weeds push through and moisture evaporates; much over 100mm and light rain never reaches the soil. Keep mulch a hand width clear of trunks and stems to prevent collar rot.

How does delivery work for heavy bags?

Substrates are delivered Australia wide alongside your plants, with delivery from $29.95 and a minimum order of $300 before delivery, which a planting project clears quickly once mix, mulch and fertiliser go in the cart together.