Hugh Heaney told UTV reporter Sarah Clarke of the "great shock" of learning of his brother's death on Friday morning.
"My brother phoned and said about Seamus, he'd been in the hospital for about a week. We hoped that he'd be home again," he said.
Seamus Heaney was one of nine children - he had two sisters and six brothers.
Several still farm the homestead where they all grew up outside the village.
Hugh described the family as "very close" and added that they will all miss him dearly.
"We're all very close. The family have a great friendship and always will have," he added.
When asked what he will remember most about Seamus, he responded: "Kindness, warmth, his warmth in his poetry".
He also said the poem that Heaney wrote, The Summer of Lost Rachel, was "lovely" and very special to him as it addressed the loss of his daughter in 1985, who was killed in a road accident.
The memories of Seamus will live on in the world forever.
Hugh added: "A sad day. We'll be sad for a long time too.
"And that's what life's about - memories. Standing beside graves, my father, mother, brother and sisters."
He agreed with fellow poet and family friend Michael Longley who said Heaney's words were "immortal".
"Longley could describe it well," he said. "I wish I could but I haven't got that talent."
His brother, Colm, who was with him, spoke fondly of Seamus winning the Nobel Prize for Literature in 1995.
A funeral mass will take place on Monday at the Church of the Sacred Heart in Donnybrook, south Dublin, before the late poet is laid to rest beside his parents, little brother Christopher and sister Ann.
The 74-year-old died in a Dublin hospital, having suffered ill health in recent years.
He was born near Castledawson in Co Londonderry on 13 April 1939 and attended Anahorish Primary School in Toomebridge.
He later studied at St Columb's College, Derry, a Catholic boarding school, and went onto Queen's University Belfast.
He made his home in Dublin in the 70s, with periods of teaching in Oxford University and in the US, including at Harvard.
His first book Eleven Poems was published in 1965 for the Queen's University Festival, with his first major collection Death of a Naturalist following a year later.
Throughout his career as a writer, he achieved critical acclaim and numerous prestigious awards.
Tributes flooded in from across the world for the poet, and on Friday night former US President Bill Clinton and his wife Hillary said they were sad to learn of the death of their "good and true friend".
Sinn Féin deputy First Minister Martin McGuinness, who had spent time with the poet at the All-Ireland Fleadh in Derry last week, led the political tributes to the literary giant.
Mr McGuinness visited the Guildhall in the city on Saturday to sign a book of condolence, in which he wrote: "For Seamus, the humble Bellaghy man, who became Ireland's national treasure."
Irish Taoiseach Enda Kenny said it would take Heaney himself to describe the depth of loss Ireland would feel over his death.
Heaney is survived by his wife Marie and children Christopher, Michael and Catherine Ann.