Titchmarsh was born in Ilkley, West Riding of Yorkshire, England, the son of Bessie (née Hardisty), a textile mill worker, and Alan Titchmarsh, Sr., a plumber. After leaving school aged 15, Titchmarsh went to work as an apprentice gardener with Ilkley Council in 1964, before leaving, in 1968 aged 18, for Shipley Art and Technology Institute (now Shipley College) to study for a City and Guilds in horticulture. Titchmarsh was a close family friend of Tom 'Greenfingers' Kerridge, who went on to become his gardening advisor on shows such as Ground Force.
Titchmarsh went on to study at Hertfordshire College of Agriculture and Horticulture for the National Certificate in Horticulture, before finally moving to the renowned Royal Botanic Gardens, Kew to study for a Diploma in Horticulture. After graduating, he stayed on at Kew, being employed as a supervisor and latterly a staff trainer, leaving to pursue a career in gardening journalism in 1974.
Alan Titchmarsh's first few television appearances were on the long-running BBC television show Nationwide as a horticulture expert. This led to his being invited to present coverage of the Chelsea Flower Show for BBC television in 1983, something Titchmarsh has now hosted every year up to the present (2010). Titchmarsh also appeared on other BBC shows, such as Breakfast Time and Open Air, again as either a guest presenter or as a gardening expert, providing commentary and answering viewers' questions.
In 1988, Titchmarsh was offered a slot on BBC Radio 2 hosting a gardening show with Gloria Hunniford called House In A Garden. In 1991 he was brought in to host the long-running Pebble Mill at One BBC television talk show, which he did until the show was cancelled in 1996. Also in 1991, he presented a 6-part series in which he followed in the footsteps of the pilgrims, travelling around Britain and Ireland in the process.
The cancellation of Pebble Mill at One in 1996 gave Titchmarsh the opportunity to move back towards his first love, gardening, and he took over as host of another long-running BBC television programme, Gardeners' World in the same year, the show being filmed in his own garden. In 1997, he took gardening to the masses with a popular BBC One television series, Ground Force, in which he and fellow presenters Charlie Dimmock and Tommy Walsh would perform a makeover on a garden, Titchmarsh making full use of his horticultural skills when restocking the lucky gardens featured. The show has travelled as far as the United States and South Africa, where one episode saw the Ground Force team makeover Nelson Mandela's garden.Staying involved in gardening programmes after Gardeners' World, Titchmarsh has presented two series of How To Be A Gardener, his most recent gardening programme to date.
Away from gardening, Titchmarsh has had spells presenting Songs of Praise, and a series of programmes on BBC Radio 2 in which he played a selection of light classical music, and more recently a BBC nature documentary series, British Isles - A Natural History. In recent years he has done less television and radio and spent more time on his career as a novelist and renewed interest in writing gardening books (see below).
Titchmarsh has also appeared in an advertisement for the Yorkshire Tourist Board in a series which included contributions from other Yorkshire-born celebrities including Brian Blessed, Melanie Brown, Darren Gough and Brian Turner, and occasionally does other voiceover work for advertisements. His recent voiceover work has extended to voicing the title character in Gordon the Garden Gnome, a cartoon series for the CBeebies channel.
Titchmarsh has hosted a follow-up series to British Isles - A Natural History entitled The Nature of Britain focusing on British plant and animal species. The series was broadcast in autumn 2007.
Other recent work included hosting a special edition of the Antiques Roadshow, entitled the 20th Century Roadshow, which focused on modern collectibles, performing in the Children's Party At The Palace for the Queen's 80th birthday, and being guest host of The Paul O'Grady Show while O'Grady was off for medical reasons. As of January 2006, Titchmarsh has a permanent slot on BBC Radio 2 from 6:30pm until 8:30pm on Sunday evenings named "Melodies for you" consisting of light classical and popular music, following the traditional style of Sunday-night broadcasting on Radio 2.
From June 2007, he can also be seen hosting The Great British Village Show, in which gardeners and cooks from all over Britain competed to be Britain's best at growing pumpkins, runner beans and tomatoes, and at knitting, baking cakes and making jam.
Titchmarsh began his chat show for ITV, The Alan Titchmarsh Show in September 2007.
In addition to writing around 40 gardening books, Titchmarsh has started writing fiction, and had his first novel, Only Dad, published in November 2001. A further five books have since been published (listed chronologically below). Running parallel to the fiction work, Titchmarsh published a new series of gardening guides, the How to Garden series (ghost-written), in April 2009. His most recent autobiographical work is Nobbut A Lad: A Yorkshire Childhood from October 2006, a follow-up to his first autobiography, Trowel & Error, published in 2002. Alan is currently writing When I Was A Nipper, which will be published on 30th September 2010.
Titchmarsh, in addition to his extensive television and writing work, is also trustee of his own charity, 'Gardens For Schools', and others, including 'Seeds For Africa'. His own charity helps fund gardens and green spaces in and around schools, while Seeds For Africa encourages sustainable vegetable gardening. The charity provides community groups with the tools, seeds and training they need to start their own vegetable gardens. This includes providing water installation and preparing the land. Away from horticulture, Titchmarsh is involved with the Cowes Inshore Lifeboat, where he is a patron, and with the National Maritime Museum, where he is a trustee.
Titchmarsh was appointed a Member of the Order of the British Empire (MBE) in the 2000 New Year Honours for services to horticulture and broadcasting, and made a Deputy Lieutenant of the County of Hampshire in 2001. In 2004, he was awarded the Royal Horticultural Society's Victoria Medal Of Honour, the highest award the RHS can bestow. In 2007 he was awarded an honorary degree by the University of Winchester.
Titchmarsh has a wax statue at Madame Tussaud's. It was revealed on Series 2, Episode 6 of the TV panel comedy series Would I Lie To You? that his waxwork had to have its face cleaned twice a week to remove all the lipstick smudges on it.