Ralph Hoare from Gloucestershire still enjoys his passion for growing vegetables and cultivating flowers at the ripe age of 104.
The keeper of around 200 rose bushes said he allows for his weak knees by using a hoe for weeding and a grabbing tool for picking up items from the ground.
He also secures the help of his great-grandchildren, aged six and four, who he says are already proficient in deadheading his roses.
Mr Hoare took up gardening in 1914 when he was himself aged six and has now decided to share almost a century of experience with the Twitter generation.
The former bank worker and RAF veteran - who cites gardening as the key to his long life - will answer questions posted with the hashtag #askralph from tomorrow.
Mr Hoare was identified as the UK's oldest active gardener by retailer Furniture Village which led a hunt for an expert to respond to the nation's horticultural questions.
He will reply to queries over the coming months, in between tending to his own garden and planning for his 105th birthday party in July.
Mr Hoare said: "I have just sent off my order for my annuals.
"The seed potatoes are sprouting in the spare bedroom and I am waiting for some dry weather for the onion sets.
"The thought of my garden in bloom gives me the willpower to continue through the winter.
"Gardening keeps me on the move and my mind active."
Born in Plymouth in 1908, Mr Hoare grew up in Devon where he remembers his earliest gardening experience of growing Japanese anemones.
He has kept the garden at his Longlevens home himself since the death of his wife Dorothy in 2007.
"She used to do all the weeding and I did the planting, pruning and digging," he said.
The couple, married in 1940 at St John's Church in Taunton, Somerset, had two children and Mr Hoare is now grandfather to six and great-grandfather to a further six children.
He said: "Now that my knees are not so good, I have to garden standing up and by asking other people to do things for me.
"I use a hoe for weeding and a grabber for picking things up from the ground. I also spend more time just wandering through the paths, admiring and smelling the roses and making mental notes of what has to be done.
"My two eldest great grand-daughters, aged six and four, have become proficient in deadheading the roses, under supervision of course."
Mr Hoare said his favourite rose is Papa Meilland because of its dark red colour and strong scent.
He also has a vegetable garden where he grows potatoes, onions, runner beans and broccoli.
Friends and family will mark his 105th birthday with a party in Mr Hoare's garden.
Members of the public can put questions to Mr Hoare via the official Furniture Village Twitter account (@OfficialFV). His answers to selected questions will be posted throughout the summer.