Mulch for Raised Garden Beds
Calculate how much mulch you need to top a raised vegetable or flower bed.
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Recommended depth: 50-100mm for garden beds
Total Volume
Mulching Your Raised Garden Beds
Raised garden beds benefit enormously from mulching, particularly vegetable gardens where moisture retention directly affects your harvest. A standard raised bed of 2.4 metres by 1.2 metres, commonly built from sleepers or kit systems, needs a lighter mulch layer than ornamental gardens. At 50mm depth, this 2.88 square metre bed requires approximately 0.14 cubic metres of sugar cane mulch to provide effective coverage without overwhelming your plants.
The weight of 0.14 cubic metres of sugar cane mulch is only around 28 kilograms, light enough to carry in a couple of bags from your local garden centre. This small quantity makes bagged mulch the practical choice for most raised bed applications. Sugar cane mulch is specifically recommended for vegetable gardens because it breaks down relatively quickly, adding organic matter to the soil while being easy to move aside when planting new seedlings.
Why Raised Beds Use Less Mulch Depth
Vegetable gardens require a lighter touch with mulch than ornamental plantings. At 50mm rather than 75mm, you get the moisture retention benefits without creating problems for your vegetables. Many edible crops need warm soil to thrive, and excessive mulch can keep soil too cool, particularly in early spring. The shallower layer also makes it easier to work around plants, plant new seedlings, and harvest without constantly disturbing deep mulch.
Choosing Mulch for Edible Gardens
Sugar cane mulch is the go-to choice for vegetable beds because it's lightweight, breaks down to improve soil structure, and doesn't introduce problems like nitrogen drawdown that can occur with fresh wood chips. Pea straw is another excellent option for veggie patches, while lucerne mulch adds nitrogen as it decomposes. Avoid cypress and treated wood mulches in vegetable gardens, as these can affect plant growth or introduce unwanted chemicals.
Got multiple raised beds to mulch? Use our main mulch calculator to add up each bed and get your total order.