Although inexperienced, felt to have growing capability (5-8)
I believe the answer is:
green-fingered
'growing capability' is the definition.
The definition suggests an adjective which matches the answer.
'although inexperienced felt' is the wordplay.
'although inexperienced' becomes 'green' (similar in meaning. I am not sure about the 'although' bit.).
'felt' becomes 'fingered' ('finger' can be a synonym of 'feel').
'green'+'fingered'='GREEN-FINGERED'
'to have' acts as a link.
Can you help me to learn more?
(Other definitions for green-fingered that I've seen before include "Having the knack of making plants grow well" , "Able to make plants grow well" , "Possessing natural gardening skills?" , "Adept at gardening" , "Having aptitude at growing plants" .)