And as grounds manager at the only university to have won a Green Flag award for its campus, and nominated for an RHS Associate of Honour, Cooke is proud of his achievements.
"The grammar school I attended said I couldn't study horticulture and wanted me to do marine biology. Fortunately, a friendly parks manager in my home town of Felixstowe pointed me in the right direction," laughs Cooke, who now lives in Nottingham.
"People from schools try to send young lads to me and the attitude is they're not much good at anything, so let's try horticulture and that is the wrong attitude."
Cooke's career is a case in point; not only has he steered the University of Nottingham towards a Green Flag every year since 2003, he is the author of five books on various aspects of horticulture including bamboos and grasses, tender perennials and growing cannas.
An interest in exotics led Cooke to develop and manage the national Canna collection for many years, until it was hit by a virus after a move from his nursery in the West Country to Nottingham.
The university's walled garden, once part of 18th-century Highfields House, is a favourite of Cooke's and he has worked hard to develop it as a quiet oasis in the middle of the bustling campus. The garden has been replanted in a late-Victorian style using exotic plants such as hardy bamboo and banana Musa basjoo Award of Garden Merit. "It is my own design and is one of my favourite parts of the university grounds because it has a touch of history, as well as the plants I love," adds Cooke.
Set in a beautiful landscape park that has formal displays, wildflower meadows, a lake and hundreds of trees, the University of Nottingham is dedicated to high levels of maintenance and horticultural excellence, he says.
A desire to involve the community in the 200ha of green space was a priority for Cooke. He encouraged the university to set up its own friends' group for the parkland, as well as organising activities such as bat and bird walks, and entries to Green Flag and local and national In Bloom contests.
"Initially, I did get a few complaints because some of the staff thought it would be more work, but now they love the challenge and the fact that people like what they are doing," says Cooke.
"It's good for staff morale to know they are valued and people do notice."
He adds: "Universities are sometimes criticised as being elitist. Local people did say to us they didn't know they could come on campus, so now we organise lots of events and concerts. This way we can give something back to the community, even though it is not a public park."
"I have been disappointed no other universities have taken it up because there are so many benefits."
Cooke is notorious as a workaholic, among the 42 staff he works with. And despite his planned retirement at the end of the month, he is showing no signs of slowing down.
Following a lecture and study tour of the US in 2000, Cooke fell in love with the landscapes of California and now intends to spend six months a year there.
He will join partner Philip Daly, who works as a nurse in Palm Springs, and plans to study desert landscapes in more detail, as well as writing his next book, examining planting design.
"There is a big move in California to create sustainable landscapes, so although irrigation has been widely used in the past, there are a lot more plants native to California," says Cooke.
"Sustainable planting is likely to become more popular in the UK as well and Nottingham has developed a distinct style we call 'Nottingham Contemporary', which includes more grasses and herbaceous plants. It is environmentally sound and sustainable and is the way forward."
Cooke may be waving goodbye to that unique Nottingham style, but it looks like retirement is just the start of the next stage of his horticultural career.
1968-72: Achieved Dip Hort, Adv Dip Hort and Master of Horticulture at
1972-74: Landscape manager at Barralets of Ealing
1974-80: Lecturer at Norwood Hall College of Horticulture
1980-91: Superintendent of grounds at the University of Reading
1991-93: Gardens manager at National Trust at Ascott, Bedfordshire
1993-94: Owner/manager of Brockings Exotics
1994-2008: Grounds manager at the University of Nottingham