The Prince of Wales wrote to ministers about the benefits of complementary medicine, the need for affordable rural homes and the threat to heritage buildings, previously secret letters have revealed.
Six letters written by Charles have been published by the Government and show how the heir to the throne raised issues close to his heart with the heads of departments.
The correspondence is the second batch of letters that Guardian newspaper journalist Rob Evans fought a long-running battle to gain access to, following a freedom of information request.
Clarence House made another robust defence of Charles's right to write to ministers and said in a statement the correspondence showed "the range of the Prince of Wales' concerns and interests for this country and the wider world".
In total 17 letters, written by ministers, the Prince and his private secretaries between September 2007 and June 2009, were released and they even revealed tackling the weed ragwort was an issue that concerned Charles.
Correspondence between the Prince and the then health secretary Alan Johnson from 2007 reinforced the Prince's long-held view on the benefits of complementary medicine.
In a letter from September 2007, the Prince wrote: "I cannot bear people suffering unnecessarily when a complementary approach could make a real difference."
He went on to say: "In addition, I am sure that more can be done to take advantage of complementary medicine, not as an alternative or competitor to conventional medicine, but as part of an integrated approach with the same doctor being able to provide or suggest conventional and/or complementary remedies and treatments as he and the patient see fit.''
In a statement, Clarence House said the Prince "believes in safe and effective, evidence-based complementary medicine integrated with, not as an alternative to, conventional medicine''.
The letters also reveal some correspondence between Charles and Mr Johnson about ragwort, a weed widely despised in pockets of the countryside due to its poisonous qualities, particularly to cattle and horses.
Although the Prince's original letter was not disclosed, Mr Johnson's reply hints at a previous mention of the subject when he writes, in a letter from January 2008: "The issue of ragwort and the control of its spread in the UK would be a subject covered by Defra and so I have passed this letter on to colleagues there who will respond more fully.''
The first batch of Charles's letters were released last month and revealed that the heir to the throne tackled the then prime minister Tony Blair over the lack of resources for the armed forces fighting in Iraq.
Mr Evans from the Guardian also requested access to a second group of letters and their journey through the legal process was suspended, while the first group made its way through the courts.
The Government has now put them in the public domain in light of the decision of Supreme Court justices, made earlier this year, to quash an order which blocked the publication of the first batch of correspondence.
In one letter, released today almost exactly six years after it was originally sent to then culture secretary Ben Bradshaw, Charles asks the Labour MP to get in touch and "discuss various heritage matters".
In the letter, from June 2009, Charles briefly detailed his concerns about "major historic sites, many of which are lying derelict''.
He also hit out at "unscrupulous owners" for abandoning certain unnamed sites.
The letters are not Charles's famed "black spider memos'' - so-called because of his use of black ink, underlining and exclamation marks - but typed correspondence.
The Prince writes the initial greeting in his own hand and signs the letters.
The issue of affordable rural housing was raised by Charles when he wrote in August 2007 to Yvette Cooper, then housing and planning minister in Gordon Brown's administration.
He refers to an earlier meeting he had with Ms Cooper when they discussed affordable rural housing.
Charles then goes on to say: ''I have seen from my visits around the country the real problems finding an affordable home causes for those on low incomes in the countryside - many of whom are carrying out essential jobs, such as farm workers, teachers, shopkeepers and health workers and on whom the future viability of rural life depends.''
The issue of affordable rural housing was also raised in a letter to then housing minister Caroline Flint in May 2008.
The Clarence House statement added: "The letters published by the Government show the Prince of Wales expressing concern about issues that he has raised in public like affordable rural housing, the quality of hospital food, the preservation and regeneration of historic buildings, an integrated approach to healthcare, climate change, and others.
"In all these cases, the Prince of Wales is raising issues of public concern, and trying to find practical ways to address the issues."