Sigourney Weaver: "The past can be very troubling to the new generation"

She’ll soon be appearing as a grandmother on screen again in a mesmerising new drama called The Lost Flowers of Alice Hart, but is this a role that Sigourney Weaver, 73, also plays in real life? "No, although I have a dog... but she’s not a grandchild. Sometimes I feel like she is," laughs Sigourney.

The Hollywood legend skips away from the question elegantly, referring to the greyhound – called Cosi Fang Tutti – that she shares with her husband of 38 years, Jim Simpson, at their homes in Manhattan and upstate New York.

"I have a daughter who lives in New York, but my wonderful family of nephews and nieces are far away and now they all have children," she says. "My feeling is that I’m a far-away kind of aunt and that is very frustrating, because I can only interact with them in certain ways and see them when I can."

Her daughter Charlotte is in her early thirties, but when I gently persist in asking whether playing a grandmother in The Lost Flowers has stirred up a longing to be one for real, she gives a very careful response: "Well, I try to keep those feelings in check because my offspring is very ambivalent about all that, with the world being the way it is." Her voice briefly tightens; this sounds like a subject that may be a little too close to home for her.

"But another reason I cherish being with my nephews and nieces and their rather large families is that, as someone who has worked a lot in her life, I love being with my family and enjoying the strength of the family."

I’m expecting Sigourney to be quite grand - as one of the most respected actors on the planet - but she is friendly and full of joy when we meet to talk about her incredible career, blooming as it is once again. She will play a formidable Australian matriarch in The Lost Flowers, a screen adaptation of Holly Ringland’s popular novel, which has echoes with her own life. Her character, June, refuses to talk about difficult things, which Sigourney says sounds familiar.

"My mother was British and she was a great gardener and I remember one of my nieces saying to me: 'I wish Granny would talk to me as much as she talks to the flowers'," Sigourney recalls. Again, her tone of voice suggests this was difficult for her too. "My mother treated the flowers like little children and they thrived."

"I throw myself at the garden without getting my gloves. I’m always pulling up weeds, then my nails are black for the next month."

Sigourney was born Susan Weaver in New York City in October 1949, the daughter of Elizabeth Inglis, an English actor from Colchester who worked with the great Sir Alfred Hitchcock on 1935 spy film The 39 Steps.

"I would have loved to have talked with her about it but she was so private," Sigourney once said. Her mother never spoke about her acting career at all, having given it all up when she married Sylvester "Pat" Weaver, a successful American television executive.

Young Susan was once told by her mother that she was not pretty, "just plain". Undeterred, she took the name Sigourney from a minor character in F Scott Fitzgerald’s The Great Gatsby when she was 14 and set out to make her way as an actor. This was despite already being nearly 5ft 11in tall and feeling like "a giant spider". She certainly realised her dream, making her breakthrough in the 1979 movie Alien and going on to star in three sequels as Ellen Ripley, the toughest, bravest, most impressive female action hero ever seen in the movies at the time.

Sigourney also played a possessed cellist in the Ghostbusters movies and won Golden Globe awards for Gorillas in the Mist and Working Girl. In total, she has appeared in more than 70 films, including A Monster Calls and, more recently, Master Gardener.

Now Sigourney is in the garden again for The Lost Flowers, this time in the Australian outback. She was willing to go so far for work because it meant Jim could indulge a passion of his too.

One of the things that helps me enormously and is very lucky is that my husband has retired from working in the theatre and he’s now able to travel with me," she says. "That was a big reason I took the job in Australia, because he’s a surfer. Everything about the project was irresistible."

Her character, June, spends much of her time out among the wildly beautiful Australian flowers, something which is close to Sigourney’s heart.

"I am a gardener," she says. "I came to it late. I was at the Chelsea Flower Show this year, as a matter of fact. I hope the British and Irish gardeners I met there tune in, because the show is a love letter to plants and the healing nature of gardens."

So what is her own outside space like? "The garden I have upstate is mostly what in the old days people would have said were weeds: wildflowers," she says. "It’s a native plant garden with grasses and the few things that will grow up in that zone." She loves it there.

"Having a garden at this point in my life, as a lifelong apartment dweller, is one of the most glorious things I could ever have. We get so much pleasure from looking at it and walking through it."

"I’m no longer starting a job saying: 'Can I do this?' It’s now: 'How am I going to do this?'"

Does she have a gardener or does she get her own hands dirty like June? "The mark of a true gardener is that they put their gloves on," she smiles. "I’m such a novice still that I throw myself at the garden without going to get my gloves. I’m always pulling up weeds, then my nails are black for the next month. So actually, among the few things I took away from making The Lost Flowers were two pairs of well-used gardening gloves that June wore."

In the series, June rules the roost as the owner of an isolated flower farm staffed by women who have found refuge there from abusive partners. Her younger self is seen in flashbacks, as the past returns to haunt her, and the secrets of the women slowly unfold like the flowers.

"I loved the scope of June," says Sigourney. "It was exciting to play a woman from a very early age right through to the end of her life. I had a brilliant make-up artist and wigmakers. I love transforming with a role if I can."

Her height, for which she was teased as a teenager, is now a strength and an asset. "I was pleased because I was able to use the fact I’m a big, tall woman in a very June-like way," she says. "My posture, the way I walk, the way I hold things, everything was working with me to create this woman."

The imposing June takes in the title character, a little girl called Alice who believes she is to blame for the death by fire of her mother, her violent father and her unborn brother. In time, Alice leaves the farm and June longs for her return.

"That resonates with me," says Sigourney, whose parents were away from home a lot for work when she was growing up – something that left her feeling isolated and lonely as a child. "The family trauma in The Lost Flowers is quite removed from my own situation, which was a poor little rich girl scenario where I wanted more connection to my parents than I had. But you look back and you go: 'God, they must have thought this was for the best.' I have a different appreciation now."

An Anglophile, Sigourney appeared twice in Doc Martin because her friend since the 1970s, Selina Cadell, played the village pharmacist in the Cornish drama. But she also has a sense of the darker side of the English character.

"Having had an English mother, there are so many things you don’t discuss," she says. "But the power of the past, if you never talk about it, can be very troubling to the new generation." Her mother died in 2007. "The solution is to get it all out there, but I hope you’ll agree with me that’s not very British."

Not so long ago, Sigourney’s career would probably have been as dead as a daffodil in winter by now, but Hollywood has fallen in love again with older women, including the likes of Dame Judi Dench and Dame Helen Mirren.

"I feel very lucky that my seventies coincided with the growing awareness in the movie business that great stories have great women’s parts in them of all ages," she says. "It used to be that when there was an older woman she was a caricature of an evil mother-in-law or what have you. Nowadays, I don’t think that’s true."

Actually, new technology seems to mean anyone can play any age, as long as they’ve got the right attitude. The last time we saw Sigourney on screen she was playing a blue-skinned teenager nearly 60 years younger than herself in the blockbuster Avatar: The Way of Water. "You really can do so much these days, it’s a wonderful time to be an actor," she says.

It was the second time Sigourney had appeared in James Cameron’s epic franchise. Her human character Dr Grace Augustine was killed off at the end of the first film but she has returned as Kiri, the biological daughter of Grace’s avatar and one of the blue Na’vi people fighting a war against environmental destruction. Sigourney has now signed up to be part of at least another two Avatar sequels.

She lends far more than her voice to this state-of-the-art animation, donning a performance capture suit to move around the set as a teenager.

"Avatar was such an unusual opportunity, but since I was such an uncomfortable 14-year-old [in real life], it was a really wonderful opportunity for me to bring that creature out and set her loose on the story."

Age and experience have certainly brought self-belief for Sigourney. "I’m no longer starting a job saying: 'Can I do this?' It’s now: 'How am I going to do this?' I feel like I bring so much with me, in terms of my craft and my courage and my curiosity, and my appetite for work and my sense of adventure."

Long may it continue for the actor, who on the evidence of The Lost Flowers of Alice Hart is absolutely at the top of her game, as wise as a septuagenarian, and as playful as her Avatar teenager. As she says herself: "I get these opportunities – comedy or drama, huge or tiny – and I pinch myself."

The Lost Flowers of Alice Hart is available on Prime Video from 4 August