Shades of red on the borders in the garden (4)
I believe the answer is:
shed
'the garden' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'shades of red on the borders in' is the wordplay.
'shades of red' becomes 'sd' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'on' means one lot of letters goes inside another (as in clothing \'on\' a person).
'the borders' says to hollow out the word (remove centre letters).
'in' becomes 'home' ('he's in' can mean 'he's home').
'home' with its middle removed is 'he'.
'sd' going around 'he' is 'SHED'.
Can you help me to learn more?
(Other definitions for shed that I've seen before include "Shack" , "Slough - outbuilding" , "Abandon" , "storage facility" , "Outhouse for storing garden tools etc" .)