The Metropolitan Golf Club Green Restoration Project

The Metropolitan Golf Club is one of Australia’s premier golf courses and is located on Melbourne’s world famous Sandbelt. It is renowned for its large, firm and fast greens that are hand-mown right to the edge of the greenside bunkers. The club is undertaking a major project to rebuild all putting surfaces over the next few years.
STRI Australia was appointed to provide agronomic advice and laboratory testing during this exciting project. The club had high expectations that the new putting surfaces would perform consistently and to the standard the course is known for. To ensure expectations were met the project required extensive planning and testing.
Stage 1
Trials and assessment
The Metropolitan Golf Club set up Bentgrass variety trial plots several years ago to assist in determining the preferred Bentgrass variety and profile to use for restoring the putting surfaces. The trial received the same maintenance and cultural practices as the greens on the golf course.
  • Soil moisture content
  • Surface firmness
  • Green speed
  • Green smoothness and trueness
  • Quantitative assessment of organic matter, thatch levels and root growth.
Stage 2
Sampling
Extensive sampling and testing of sands from around the golf course was undertaken to determine its’ capacity for sourcing suitable material. This involved:
STRI undertook independent assessment of their performance using the Trueness Meter Programme. We measured:
  • A geo-tech investigation of the rootzone media and native sand subgrade from all putting greens to determine depths of material
  • Laboratory testing of particle size distribution, saturated hydraulic conductivity, particle shape, pH and salts
  • A desktop analysis to:
    • Estimate the total volume of sand required to complete the green’s restoration project
    • Identify and estimate volumes of suitable sands on the golf course that could be used
    • Determine the additional volume of sand required (i.e. shortfall) to be sourced from local suppliers
Stage 3
Trials of recommended sand options
Multiple trial blends were made up using different ratios of the on-course stockpiles with various imported sands and then tested in the laboratory. The two main parameters used for determining the optimal blend were:
  • Meeting the desired rootzone criteria for drainage, particle size distribution and particle shape
  • Minimising the percentage of the imported material
The final rootzone blend for the green restoration project was very similar to the rootzone of many of the existing putting greens and was also typical of Sandbelt sands.
Stage 4
Green rebuilding
The greens were to be rebuilt using the California construction method which entails a pure sand rootzone above the subsoil and a drainage system. Potential drainage materials to be used around the pipe and for backfilling trenches were tested for their suitability as well as their compatibility with the rootzone media.
Stage 5
Future proofing
Processes were developed for the on-site blending and quality control testing to ensure consistency and performance of the final rootzone media. A trommel screen was used to blend the component sands and the drainage rate of the blended material was tested every 250m3 to ensure it met the desired range.
The practice putting green is the first of the many putting surfaces to be rebuilt over the next few years.