Research is best left until you've written the first draft and know exactly what you need. If you need to speak to an expert then you don't waste their time by asking questions when you won't use the answers. While you are writing your first draft, assume that the facts will be there to support your imagination and write what you'd like to have happen. For example, in Nice Girls Do I needed my main character to injure herself in such a way that it was impossible for her to move for a few days, but for her to recover completely after a week or so. As I was writing I made the assumption that such an injury could exist. After the first draft was finished I found my expert (thanks, Craig Davey) who told me that a partial lateral tear of the ligaments would give exactly the symptoms I needed for the purposes of the story.
Why do readers read novels? Yes, an interesting background adds to the experience, but essentially they are reading for the story. If they want to know about Stourhead or Stancombe (to name two gardens I used as background for Nice Girls Do) then they will read a non-fiction book about them and/or visit them. Too much research and there's a risk of clogging up the story telling process. So if you're writing and you're tempted to do a bit of research rather than write that difficult scene - just say no. Write now, research later.