Pick up from valley around start of autumn (5)
I believe the answer is:
glean
'pick up' is the definition.
(thesaurus)
'valley around start of autumn' is the wordplay.
'valley' becomes 'glen' (glen is a kind of valley).
'around' means one lot of letters goes inside another.
'start of' suggests taking the first letters.
The initial letter of 'autumn' is 'a'.
'glen' going around 'a' is 'GLEAN'.
'from' is the link.
(Other definitions for glean that I've seen before include "Collect grain (or information?)" , "Gather (information) bit by bit" , "Collect gradually (from various sources)" , "Learn by gathering bits" , "Angle (anag.)" .)