Mourners are invited to Priory Court Hotel in Pevensey, East Sussex after then funeral.
Nielsen ran Nielsen Plants in Hellingly, East Sussex for 47 years and was a pioneer growing pot plants in the UK. He was a well-known face in the industry and prominent in plant producer organisations.
Allensmore Nurseries' Brian Taylor said: "He was a great grower."
Peter Hill of Hill Brothers said: "I knew Bent quite well as a fellow flowering plant grower. He was a very nice chap and a very accomplished grower.
He grew plants ranging from the first regal begonias in the UK, campanula, pot roses, mini Christmas trees, gerbera and poinsettia.
His wife Pat worked on packing and presentation and Hill said their "attention to detail was incredibly good."
"Being a Dane helped him bring in new products from Denmark to this country."
Hill said Nielsen was one of the top growers in Europe in his heyday in the 1980s and was innovative in what he grew and how he grew it.
"Nielsen Plants got as close to becoming a recognised brand as Rochfords was in the years prior. Bent was a very early pioneer of biological control. His Hellingly nursery was like a college for young growers who went into the wider industry."
Hill said Gary Shorland from Double H, Kevin and John Madsen and many more worked at Nielsen's at one time, as did manager Mike Holmes.