He brushes past the lush greenery behind Dove Cottage at Grasmere on to the terrace where Wordsworth paced up and down as he worked.
"The spot commands a view over the roof of our house, of the lake, the church, helm crag and two-thirds of the vale" quotes Mr Kirkby from a letter that Wordsworth wrote to Samuel Coleridge.
Mr Kirkby's intimate knowledge of verses, letters and journals has enabled him to recreate the quarter-acre garden as the Wordsworth family knew it during the eight years they lived in the Lakeland cottage at the beginning of the 19th century.
It has taken 25 years but, says Mr Kirkby, his work on Words worth's "domestic slip of hill" is as close to being finished as it ever will be.
"Wordsworth would recognise this garden if he were to walk into it now. There will always be something to do, something to add, but I feel I have finally captured the spirit of Wordsworth's garden."
When Mr Kirkby first arrived to work as a guide at the cottage, which is owned by the Wordsworth Trust, it was almost stripped of anything the family had known. "It was well kept of course but manicured rather than natural and had thousands of daffodils, the hybrid kind with big heads which would never have been here in Wordsworth's time. We do have some daffodils, just a few wild ones, which are found locally," says Mr Kirkby.
"Wordsworth had very definite views as a gardener. They are not everybody's idea - too wild for some tastes - but I'm glad to say more people are coming round to his way of thinking.
"He felt nature could not be improved upon. Things had their place, and exotic plants and trees did not belong within an English cottage garden.
"Wordsworth and his sister Dorothy collected indigenous plants and shrubs from the fells and lakeside. Some might be considered weeds by others. I don't think that's something we would encourage today. We have grown the various plants ourselves from seed or cuttings, sometimes travelling as far as Norfolk to find them."
Dorothy's journals are an almost perfect record of what she collected and planted. She went to a blind man in the village for a plant called London Pride , took up orchisis from the lakeside, and gathered wild thyme and columbine from the hill above the house.
She was fascinated by white foxglove and made a special trip rowing across the lake to Loughrigg Fell where she gathered seeds to plant.
Much of the Wordsworths' lives centred around the garden and much of Wordsworth's poetry reflects its importance, says Mr Kirkby.
The poem devoted to his garden is Wordsworth's A Farewell commemorating his departure to meet Mary Hutchinson, whom he married in October 1802. Immediately on their return they "went by candelight into the garden and were astonished at the growth of Brooms, Portugal Laurels".
The garden was a place where Wordsworth loved to observe and then write about nature as in his poems The Green Linnet and To A Butterfly. He also wrote To The Small Celandine, which his sister said was his favourite flower.
Mr Kirkby adds: "Wordsworth felt strongly that houses should harmonise with the surrounding landscape, and he covered the harshness of the whitewash of Dove Cottage by growing roses, honeysuckle and training runner beans up the walls.
"I've grown runner beans on the cottage walls and it looks wonderful. Sometimes I can't wait for the roses to die back to make way for the beans."
When the Wordsworth left Dove Cottage it was occupied by Thomas de Quincy who destroyed the moss huts in which the poet spent many hours, as well as the trees and plants - an incident which led to a breakdown in the relationship between the two families.
It was soon time for Mr Kirkby to return to his own garden at a cottage across the way, and he offers a last snippet of information "It's a little known fact but Wordsworth had a name for the watering can. He called it Kubla, after the title of Coleridge's Kubla Khan."Reuse content