GARDENING The project down in Cornwall, just outside St Austell, which has sustainability at the very core of its existence, ironically, found last year that a dip in visitor numbers made the venture unsustainable — not without big cuts, anyway.
The appalling weather, competition from the Olympics and the recession were blamed for visitor numbers dropping below the million mark in 2012 for the first time since it opened in March 2001.
When you have a venture employing 450 people, and rely on having £31 million to spend each year maintaining it, you are dealing with big decisions — especially when you want to do good things in educating visitors and run the whole panoply of programmes the charity does.
I visited a couple of years after it opened and, like most who have seen it, was in awe at what was created as a result of the vision of Tim Smith, who was knighted for driving it through — against all odds.
As a family, we did our little bit for Eden last week, paying to see how it has grown into its Cornish claypit in the near decade since we were last there. We bought our tickets at a time when there are all sorts of two-for-one deals to attract people there.
It, and the Lost Gardens of Heligan nearby, are the twin tourist hubs around which regeneration of a whole region has revolved, and in both, the plants are the stars — in stellar abundance.
Eden is not just about the tropical and Mediterranean "biomes", and the sheer scale of the biggest structures of their kind in the world, it’s about the message contained within them, and outside, on the terraces which punctuate the old claypit on the way down.
There, the importance of plants to our very existence and of pollinators, the insects, is underlined in dramatic fashion.
The swathe of annual meadow and the message conveyed, that intensive agriculture has left only tiny, isolated, pockets of traditional meadow, seems to have struck a chord down West, where roundabouts and verges, are a blaze of meadow colour at this time of year.
The two biomes, though, are of impressive stature, and dominate the whole experience by their sheer scale.
The Mediterranean dome is 443ft long, 213ft wide and no less than 115ft high. It features plant species not just from the Med region but from South Africa and California too.
It houses familiar warm temperate and arid plants such as olives and grape vines and various sculptures.
But it is dwarfed by the tropical house which covers 3.9 acres of ground, nearly double that of its neighbour, and is 180ft tall. That is impressive.
To take advantage of that this year it is possible for those strong of heart to scale the steps in the hot, humid, environment to a new aerial walkway, a vantage point that underlines the scale of the endeavour.
On a steaming day, I took the pleasure of "flying" over it all. There is a now a zip-wire, which is worth a tenner of anyone’s money, and you can look down on an enterprise — quite correctly described as an eighth wonder — flashing by.
One thing I did not know before the second visit was that the panels which make up the domes are so amazingly wafer thin, the plastic gaining its strength from being inflated.
As well as being revolutionary they are big, too, ranging in size up to nearly 30ft across. They encase what is described as "the largest rainforest in captivity anywhere in the world".
Contained within them is a message that simple, practical, steps can be taken both by governments and by consumers to look after our world.
That message is underlined by illustrations of charred rainforest contrasting with the beauty of the pristine jungle world, the crops which can be harmonious to the jungle world, contrasted to those that are not.
It highlights the fact that three football pitches of jungle are lost every second to de-forestation.
That’s disturbing enough, but more chilling is that if the entire world consumed at the rate of the United States we would need five planets to sustain that.
Sculptures outside include a giant bee and a robot made from old electrical appliances and illustrates the waste of resource and the sheer volume of stuff that we use.
Another thing I didn’t know was that the huge quantities of water needed to create the humid conditions of the Tropical Biome, and to serve the toilets, are all rainwater that would otherwise collect at the bottom of the old kaolin quarry.
The only mains water used is for hand washing and in the kitchens.
The complex also uses electricity from one of the many wind turbines in Cornwall, that were among the first in Europe, and the charity has permission for a geothermal energy project to provide it, and 5,000 nearby homes, with electricity.
It must be at least 15 years ago that I remember the then leader of the IW Council, Morris Barton, proposing that the Island should be at the vanguard of a similar Green scheme to that of Eden.