Garden Basics 50L Pine Bark Mulch

Pine bark mulch does two jobs in a garden bed: it slows evaporation from the soil surface and it blocks the light weed seeds need to get away. This is a 50 litre bag weighing 20kg, blended for garden beds, vegetable gardens and pots. It is the straightforward choice when you want to water and weed less often.

What it does

• Holds moisture in the soil. A bark layer cuts evaporation, so the soil underneath stays damp for longer between waterings.
• Suppresses weeds. It works by limiting light reaching the soil surface, which stops most weed seed germinating rather than killing what is already there.
• Retains nutrients. The blend is selected to hold moisture and nutrients in the root zone instead of letting them wash through.
• Breaks down slowly. Bark is a coarse mulch, so it holds structure through the season and feeds the soil as it decomposes.

How to use it

Work out the area first, then use these rates. For a 25mm top-up over old mulch, allow half a bag per square metre. For a fresh 50mm application, allow one bag per square metre. For a deeper 75mm layer, allow one and a half bags per square metre. A 10 square metre bed mulched fresh at 50mm needs ten bags.

Pull the existing weeds out before you spread, because mulching over them only delays the problem. Spread evenly to depth, keep it clear of stems and trunks, then water it in to settle it. Mulch can go down at any time of year, and a spring top-up ahead of the hot months is the one worth planning for.

What it suits

Open ground plantings. Garden beds and borders, where it does the most work, and vegetable gardens, where steady soil moisture keeps growth even and productive.

Container growing. Potted plants, where a thin surface layer slows evaporation and protects the root zone from heat. It is delivered Australia wide, with delivery from $29.95.

Two honest notes. Mulch is not a growing medium, so spread it on top of soil rather than planting into it. And at 20kg a bag it is heavy, so plan on some help getting it from the driveway to the bed.

Related products and reading

• Potting mixes, mulches and fertilisers
• How to keep weeds out of a garden bed
• Preparing soil before planting
• Browse landscaping supplies