For covering your garden bed with mulch you buy decorative mulch to your Garden Center.
But if you want mulching for cheap you must consider two options.
Get your mulch from an arborists or make your own wood chip mulch with a wood chipper.
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Step 1: What Is the Ramial Chipped Wood?
For your wood chip mulch use a chipped branches from decideous trees.
But what's the ramial chipped wood.