Imelda Staunton: ‘Umbridge’s giggle needed to be short and sharp. So I just did a boom, boom’

Imelda Staunton … ‘Having my dog in the show was fantastic because she liked everything I did.’ Photograph: Nick Thompson

You and Bill Nighy were comrades in Pride, but play estranged spouses in & Sons. Was it more fun marching alongside him or giving him a piece of your mind? MrSOBaldrick
It’s fun doing anything with Bill Nighy!

I once saw you at RHS Garden Wisley. Are you a keen gardener? What’s your favourite plant? HeyJudithB
Yes, I am a gardener. We love doing the garden. My favourite plant – this week – is the rose Munstead Wood, which has an incredible scent, and a deep, dark raspberry colour. It’s a rose we might be in danger of losing because of climate change. Roses need water, so I think we’re going to have to change our planting.