New standard for subsoils will help safeguard landscape planting

4 February 2014

Until now there has been  no standard for subsoils and as these play a big role in landscape design, it is a key area that BSI, the business standards company, has addressed with BS 8601 Specification for subsoil and requirements for use.

The subsoil is an essential component of most soil profiles and performs a very important role. It is a means of storing moisture that transmits rainfall to the deeper layers allowing trees, shrubs, grasses and other plants to root. It controls the waterlogging of surface layers, helps vegetation and crops to withstand summer droughts and provides anchorage for trees. Other crucial aspects of a good subsoil profile include reducing erosion and flooding and therefore has a direct impact on Sustainable Drainage Systems.

The standard was supported by WRAP (Waste & Resources Action Programme), British Society of Soil Science, Landscape Institute as well as several other organizations.  

Katherine Church Project Manager at WRAP said: “WRAP is delighted to see the publication of the BS 8601:2013 Specification for subsoil and requirements for use. A subsoil is a vital component of a healthy functioning soil profile, yet often its role is neglected during the specification and construction phase of a landscape project. This can cause problems such as water logging and plant mortality which can be costly to fix. The new standard sets out a benchmark on how to create a functioning subsoil.”

The standard will ensure that there is full specification of landscape soils, and will provide a mechanism by which to support the legitimate use of recycled materials, where they meet the specification. It will not apply to topsoil (which is classed by landscapes architects as the top 100 mm to 300 mm) and will also not apply to soil that is to remain in situ.

BS 8601 will help to specify requirements for:

  • The classification, composition and use of subsoils that are moved or traded for creating soil profiles intended to support plant growth
  • Multipurpose subsoil, which is fit for the majority of needs
  • Specific purpose subsoils that are acidic or calcareous, for specialist use
  • Sampling and analysis of subsoil

The standard will be of value to landscape architects and gardeners, landscape scientists, architects, construction companies and property developers, civil engineers and geotechnical and geoenvironmental specialists.

David Fatscher Head of Market Development for Sustainability at BSI said: “This standard is not just about proper landscape planting, it has far-reaching implications for the environment too especially when we think about Sustainable Drainage Systems. This is becoming even more important if we look at rainfall patterns such of those experienced recently. Now, all features of subsoils, the structure, chemistry, texture of subsoils can be closely specified by using this standard as a guide, and we can be prepared for all eventualities.”