Thanks for all the responses to my queries. I got the 18s myself and have finally got 1d - what a convoluted clue! I didn't know the abbreviation for lunchtime.
I'm not sure about 11ac. Someone said it was a hidden, but that produces a word I've never heard of, neither has my musical husband.
The Thunderbird clue is a mystery to me and I'll have another go at 2d. Meanwhile my husband wants to watch Edge of Darkness again.
Chris, no it wasn't Knighthayes, but High Garden, which is in Kenton. It will definitely be open next year as an NGS garden on 15 June. The trees were looking amazing today. It has lots of unusual plants. It was at Knighthayes I first saw a Tetrapanax. If only I had a garden that could accommodate such an amazing plant. I saw one today at High Garden.
Meanwhile my FOI was 10ac, but no LOI as yet. CODs 1ac, 25ac and 19ac. I'd never heard of 14d, despite it being one of my favourite birds.