Thanks Jono and everyone else
By the time I came back to the Forum I had finished - much to my amazement! I was going to ask for the parsing for 18ac, but I see Chris told me and 15d was a new word to me as was to a couple of others. There are a couple of others I couldn't parse - 1d, 16d and 20d. But my friend will sort me out tomorrow.
Jono, I checked my Chambers and there it was. I should have read it properly the first time. I had to look up cruciferous - and me a gardener, but I don't grow veg.
FOI was 5ac, LOI was 1d and COD was 25ac, though I must give a nod to 4d,10ac,11ac, and 19d. (It was my husband who remembered the famous phrase from the 1939 Radio show.)