Grass in English garden mown regularly in well-to-do area (10)

I believe the answer is:
kensington
'well-to-do area' is the definition.
The definition suggests a singular noun which matches the answer.
'grass in english garden mown regularly' is the wordplay.
'grass' becomes 'sing' (both can mean to act as an informant).
'in' indicates putting letters inside.
'english garden' becomes 'kent' (I've seen this before).
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternate letters of 'mown' are 'on'.
'sing' going inside 'kent' is 'kensingt'.
'kensingt'+'on'='KENSINGTON'
'in' is the link.
Can you help me to learn more?
(Other definitions for kensington that I've seen before include "neighbour of Chelsea" , "London district" , "London palace" , "Royal Albert Hall area" , "part of London" .)
