Polesden Lacey in Surrey, one of the gardens under the National Trust
More than 70% of people believe spending time in the garden may improve their quality of life, suggests a survey for the National Trust.
One in three people also considered gardens to be romantic places which could boost their love lives.
Many of those surveyed they would rather spend time in their gardens than in front of the TV or shopping.
The Ipsos MORI survey polled the responses of 956 people over the age of 15 in England and Wales.
The research was commissioned by the National Trust to coincide with the publication of its new report, Space to Grow: why people need gardens.
Fiona Reynolds, director general of the National Trust, said she was "passionate" about the idea everyone should have access to gardens and green spaces.
"In today's fast-paced world, finding space and time to unwind and relax is becoming ever more crucial," she said.
"Nowhere does this better than the quiet corner of a garden or a park that gives us the chance to breathe in our natural surroundings and refresh our weary spirit," she added.
Gardening as a pastime was also considered to be good for a person's health.
According to the Space to Grow report, 30 minutes of weeding burns the same amount of calories as a half hour walk, and gardening may even benefit those who suffer from mental illness.
"Never has access to a garden been more important for our spiritual and physical wellbeing than it is in today's rapidly changing landscape," said gardener and TV presenter Alan Titchmarsh.
NATIONAL TRUST FACTS
Employment: 450 professional gardeners
Volunteers: 1500 caring for gardens
Cost: £11m per year to maintain gardens
Visitors: more than 12 million per year to over 200 gardens
Revenue: £300m direct revenue, also more for economy each year
"The message is clear: if you want to feel better, get out into a garden," he said.
Out of those who believed spending time in gardens was important to their quality of life, 48% felt it was the most enjoyable activity above watching TV (33%) and shopping (14%), said the survey.
Another Ipsos MORI survey of 1,086 people, all above the age of 15 in England and Wales, found 80% believed children should be taught about gardening and growing plants at school.
The Trust works with the Gateway Gardens Trust which helps disadvantaged groups including inner-city children who get to plant, grow and harvest vegetables at National Trust gardens.
According to the Gateway Gardens Trust's chairman Bettina Harden, one refugee child had been so amazed by the beauty of the walled gardens at Dinefwr in Wales he "asked us whether he was in paradise".
Each year 12 million people visit the 200 gardens owned and cared for by the National Trust.