Drained fluid from bottom of well in part of garden (4)
I believe the answer is:
bled
'drained fluid' is the definition.
(eg to bleed a radiator is to drain it of liquid)
'bottom of well in part of garden' is the wordplay.
'bottom of' suggests the final letters.
'in' is an insertion indicator.
'part of garden' becomes 'bed' (flower bed).
The final letter of 'well' is 'l'.
'l' inserted into 'bed' is 'BLED'.
'from' is the link.
(Other definitions for bled that I've seen before include "Haemorrhaged" , "Seeped (into an adjoining colour)" , "Extracted blood as treatment" , "Lost blood" , "Showed effects of injury" .)