Relieved when a seed is transplanted (5)
I believe the answer is:
eased
'relieved' is the definition.
(easing is a kind of relieving)
'a seed is transplanted' is the wordplay.
'is transplanted' is an anagram indicator.
'a'+'seed'='aseed'
'aseed' anagrammed gives 'EASED'.
'when' acts as a link.
(Other definitions for eased that I've seen before include "Oiled" , "Slackened off" , "Soothed - assuaged" , "Lessened, pain or discomfort, say" , "Made less stressful or difficult" .)