Across:
   1. Medication right in treatment of patient sadness? (15)
   9. Anguish of putting our last two ingredients into cake (7)
  10.  It may deliver medication in healthy stupor ultimately (7)
  11,6dn.  Harrow possibly breaks clods and helps one obtain longer roots (3 6)
  12.  Horror storm, so tiny but chaotic (11)
  13.  Popular way to play guitar went with lead taken off banjo perhaps (10)
  15.  Lacy strap may conceal growth (4)
  18.  Cart reversing some distance (4)
  20.  Independent European country's right to eat fish (10)
  23.  Vehicles for newcomer costly (11)
  25,26.  Fresh enthusiasm and bubbling energy seen here (3 7)
  27.  Gospel is dull craft (7)
  28.  From supposed high ground of mountain, clay I so shaped (15)
Down:
   1.  Expert at using intellect taught young beginners about God (9)
   2.  Terrible disaster not repeating 8s (7)
   3.  Gruesome murders involving minor musicians (8)
   4.  Having no time to repent ruffled tidy feathers (5)
   5.  Being oddly etched, included "6 over 10" (9)
   6. see 11 across
   7.  Amazingly, fully in void (7)
   8.  Desex with injection of chlorides essentially, which may be delivered by 10 (5)
  14.  My way to obtain art (by retro method) could be ultimate achievement of faith (9)
  16.  How art produced ... method is flippant (9)
  17.  Terrible fate: lost technique for singing high notes (8)
  19.  Adapt to new way of melting rare tin (7)
  21.  100/100 ... she blitzed natural 13s! (7)
  22.  Right inside animal, where there is heart (6)
  23.  Graduate with unending enthusiasm for puzzles (5)
  24.  Famous French newspaper mostly dud (5)