The gravel mulch we're recommending for this area of your garden is
10mm Black Granite
Decorative and functional
Mulching your soil post planting will help to keep weeds at bay and help lock in moisture, reducing evaporation and therefore watering. It also protects plants and surrounding buildings/paving from soil splash, and helps keep surrounding surfaces clean.
Not recommended directly adjoining a lawn where it may get kicked onto the lawn and ‘thrown’ by a lawnmower – we’d recommend using a paving, stone or timber edging to prevent gravel migrating onto other surfaces.
If cats are a problem, we’d recommend a 14-20mm angular gravel rather than a 10mm.
Never mulch planting beds with limestone as this will affect the soil pH.
Specification:
Supply and lay 40mm depth of black granite gravel mulch to pre-planted border, laid directly on to the soil. Ensure no mulch falls into the plant foliage or damages plant foliage or stems during installation. Excludes membrane as not required.
We advise that weed membranes are NOT used and that mulch is laid directly over the soil. This is due to plant roots and soil requiring air. The installation of membranes can lead to stagnant soil and root rot.