Method: Solve the clues and fit them where they will go.

A Plant, one found among scrub (6)
B See infinitely decent sort taking on independent retail outlet (9); Spar in London area’s set to stock liquor at last (8)
C Get en croûte possibly with this vegetable (9)
D Performers in race expected previously to get first and second (9)
E Somewhat feckless Roman emperor bowled over by Virginia’s charms (7)
F Light yellow salmon found in bog (6)
G Student newspaper rejected article on the end of Richard and Judy (7)
H Success with time’s given the man courage – to drink too much (3,3,6)
I Muslim extremists are involved in blowing something up – it’s a sore point(12)
J Otto’s OK, put to sleep by this music (4)
K Organ parts unknown chap concealed in trousers (3-5)
L In Lyon the French king keeps fit with alliance member (7)
M Needing to be driven to get up after noon, ring daughter (9)
N New Labour leader harbours guilt regularly, amounting to nothing (4)
O They cause serious disease in carnivores on mutating, American maintained(14)
P Frame for harness is tapered off (3-4)
Q Prompt for speaker’s line (5); Put in an awkward position, criminal requested way out (7)
R Give one’s notice? That’s not right – join up again (5)
S Sauce needs covering if kept for gel (8)
T Real hot term not problem for such plants? (14)
U Make barking dog finally shut up in hot weather, with sons absent (7)
V Very stupid person takes a Latin subject (6)
W Reckless act? (7)
X One’s leaving relatives to go after axes and surgical tools (7)
Y Containing a certain element of touristy trash (8)
Z At Bayern Munich, for example, goals follow tight corners (1-5)