What does the British Standard for specifying trees mean?


There is a British Standard (BS 3936 - Part 1: Nursery stock specification for trees and shrubs) which specifies a standardised classification for trees supply and the respective girth sizes that should be expected.

Here is a guide to the classification:

British Standard Tree Specifications
Specification Corresponding Tree Girth Size
Light Standard (LS) 6-8cm
Standard (S) 8-10cm
Select Standard (SS) 10-12cm
Heavy Standard (HS) 12-14cm
Extra Heavy Standard (EHS) 14-16cm
Advanced Heavy Standard (AHS) 16-18cm
Semi mature 18-20cm + 

 For further information regarding tree sizing, please see "How big are Barcham Trees?"