Tall tree repeatedly planted firm (4)
I believe the answer is:
coco
'tall tree' is the definition.
'coco' can be an answer for 'tree' (coco is a kind of tree). I am unsure of the 'tall' bit.
'repeatedly planted firm' is the wordplay.
'repeatedly' indicates the doubling of some letters.
'planted firm' becomes 'co' (a firm is a company. I am not sure about the 'planted' bit.).
'co' doubled is 'COCO'.
Can you help me to learn more?
(Other definitions for coco that I've seen before include "'... the Clown, ... Chanel (4)'" , "Gabrielle Bonheur Chanel" , "French fashion designer, who branched into perfume etc" , "address for Chanel" , "Famous clown" .)