Professor Geoff Dixon, chairman of the Plants to the Rescue conference, organised by the Society of Chemical Industry in London last week, said: "Horticulture has moved in the 21st century towards what it provides to humans in terms of food, health and well-being.
"Working with plants makes you feel better. That has begun to be recognised by media and psychologists. It is now important that horticulturists raise their hands and say if you wish to apply this you need us because we are the people who know how to grow plants and do the business.
"Economists ask what we get back for our investment in nature. Evidence heard at this conference provides ammunition that justifies that expenditure."
HTA scientific adviser Dr Ross Cameron of the University of Reading, who was speaking at the conference, said: "The environment and green space drive social health."
He cited research from Swedish scientist Kristina Sundquist, who found a 72 per cent increased risk of psychosis and 16 per cent increased risk of depression in a study of four million Swedish people who lived without access to green space.
Cameron said 20 per cent of children never visit the countryside, adding that green space does not need to be parks - it could even be indoor plants. He added: "Plants make employees more productive."
Plants for People representative Jonathon Read said with people spending 80 per cent of their time inside, houseplants "are more important than outdoor plants", adding: "We can change health, welfare and business with plants."
He said research from NASA scientist Bill Wolverton showed plants eat poison and emit oxygen, reduce headaches by 45 per cent (Roger Fjeld/Tove Ulrich) and regulate heat and noise (Peter Costa).
Read said houseplants become a benchmark in new-builds, adding that Andrew Smith's 2008 research at the University of Liverpool showed plants halved CO2 levels and led to a 50 per cent sickness reduction in offices.
Read dismissed plastic plants as "plant-shaped ornaments".
Natural health adviser to Natural England Dr William Bird said the NHS forest (see p4) and formal recognition of plants' health benefits demonstrated opportunities to unlock NHS budgets.
He said the NHS' £110bn budget would be focused on key issues such as childhood obesity and that green space had "a huge role to play in that".
He added: "The natural environment will be centre stage in the Government's new 'get active' plan. These are all indications of how important green space will be in future thinking."
Subscribe to Horticulture Week for more news, more in-depth features and more technical and market info.