Pretty confident of adjoining letters but I've been wrong before.
14a Tree colour (8) C?E????? (Possibly CREOSOTE maybe)
8a Climbers clinging support looks for permission (7) ?O?T?E?
13d One told me a secret (5-4) ??C?Y ???D
19d Cut choke (7) ??O???N
5d Bovine skin a no starter when part of laughing gas compound (5) ????E