Something to plant - spot by Dundee stream (4,5)
I believe the answer is:
seed drill
'something to plant' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'spot by dundee stream' is the wordplay.
'spot' becomes 'see' (both can mean to notice or observe).
'by dundee' becomes 'dd' (I am not sure about this - if you are sure you should believe this answer much more).
'stream' becomes 'rill' (rill is a kind of stream).
'see'+'dd'+'rill'='SEED DRILL'
Can you help me to learn more?
(Another definition for seed drill that I've seen is " One used to sow".)