Your father was interior designer John Siddeley. What drew you to working with gardens? “As a kid I spent a great deal of my holiday working in the gardens in our home in Suffolk. I never thought it would be my career, having studied architecture and design with the plan of going into my father’s business. After college, when I was 20, I started working with my father. He had a client who wanted a garden designed and he gave the job to me … At the age of 21 I started my own business part time and then went full time when I realised I was getting a lot of work.”

How has garden landscaping changed in the four decades you’ve been in the business? “It’s been pretty dramatic. When I first started, if I said to a client, ‘I want an irrigation system in the garden,’ he’d say, ‘What are you talking about – it rains enough here.’ Now almost every project has an irrigation system. Technology has helped the industry considerably.”

“Marks & Spencer was one of the first to get people thinking about house plants. Before that you might find a few house plants in a garden centre, but suddenly people had more interest. Backyards were no longer dumping grounds; they were respected places where people would have their barbecues.”

What are the latest trends in garden design? “People are going for more ornamental grasses, much more natural planting. Herbaceous borders are no longer popular because they are such a huge amount of work to look after. I always say no single property is the same as the last ­– each garden has its own ingredients that go into the melting point.”

Garden smart; a glimpse at the work landscape architect of Randle Siddeley

Tell us about your project for Swire, to landscape its new commercial development in Kowloon Bay. “The brief was to create an open space where people coming out of the office building could relax. We’ve got lawns where, hopefully, they will be allowed to sit and relax. We have planted 89 [mixed, indigenous] trees – not all are standing after the [last] typhoon. I made it clear we wanted to source plants two years in advance so they came in as mature as possible. As the trees grow they will create more shade. The seating we’ve created is black granite and it’s predominant around the whole site. It creates the architectural line of the design.”

What are the main differences between working in Britain and in Hong Kong? “In the UK there are often more controls on what I can and can’t do, whereas in Hong Kong I’m left to my own devices. Once everyone has agreed on the way forward then it happens and I find that refreshing. I suspect people sometimes don’t think it’s refreshing to be working with me because I’m such a perfectionist. This recent visit I rolled up my sleeves and joined in the planting and I think some people thought I was mad, but you’ve got to leap to the front. I like to be immersed, getting my hands dirty and working with the team and showing them skills they might not otherwise know.”