The gravel mulch we're recommending for this area of your garden is

Cost effective and functional

A cost effective solution for covering low traffic areas such as behind sheds & greenhouses, or as a temporary solution where a project is phased over a number of years.

This solution should NOT be used for heavily trafficked or planted areas.

The use of a membrane under the gravel means that in time, the gravel can easily be removed and replaced.

Specification:

Supply and lay 20mm depth of gravel over Mypex or Terram membrane.  Membrane to be laid directly on to the compacted soil/ground.