From farmland to wonderland: Ballymena garden reaches BBC NI final

Ballymena man Colin Agnew reaches the Final of BBC NI’s Greatest Gardens

A Ballymena gardener whose suburban home has been transformed into a hidden botanical wonderland has secured the fourth and last place in the upcoming final of BBC Northern Ireland’s Greatest Gardens, after impressing judges with a design described as full of “mystery and intrigue”.

Colin Agnew, head gardener at Belfast’s Botanic Gardens, captured the attention of viewers and judges alike for his imaginative design, mature trees, secret spaces and striking sunken fern room in the meticulously crafted home garden.

Securing a place in the final marks a proud moment for Ballymena, with Colin’s garden — built over 35 years from what was once farmland — earning praise from celebrated gardening experts Diarmuid Gavin and Carol Klein, alongside guest judge Katie Piper, who said the space gave off “Secret Garden vibes”.

A 35-year vision brought to life

Speaking on the programme, Colin revealed the scale of the long-term vision behind the garden.

“I moved here 35 years ago and basically created the garden from scratch. So, it was a blank canvas - it was farmland, so very good ground for growing plants and particularly trees.

“I’ve planted so many trees - I can’t help myself, I just keep planting trees!

“The first two trees that I planted were Silver Cedar (Cedrus atlantica) and also a Field Maple (Acer campestre). Those two trees were a gift from a friend and one of those is now strong enough to actually support a garden swing, which speaks volumes about the strength of a good friendship.”

What began as open ground has evolved into a richly layered landscape filled with winding pathways, hidden corners and carefully designed sightlines.

“I wanted to create a kind of a wonderland I suppose, somewhere with lots of nooks and crannies, and little hidden places throughout the garden that gives that kind of magical space,” Colin said.

That sense of discovery became one of the defining features of the episode.

Katie Piper said:

“There were twists and turns, and what was behind each hedge or around each corner, or even below in sunken depths was so unexpected.”

Judges captivated by hidden spaces and mature planting

The programme followed the judges as they moved from Colin’s front garden through to the dramatic rear landscape, where mature trees, layered planting and hidden features unfolded section by section.

The front garden immediately drew attention for its bold use of colour.

Katie said:

“Instantly I was drawn to these little pockets of yellow that beautifully leads to that gorgeous display of positivity.”

Carol Klein added:

“He’s got yellow begonias by the front door, and the yellow front door - so did he paint the door to go with the begonias or did he was it the other way around?”

Beyond it, the rear garden opened into what Diarmuid described as a carefully orchestrated sequence of spaces.

“In general it’s a garden of grasses and bulbs, and it builds anticipation of what’s beyond,” he said.

That anticipation led to one of the garden’s most memorable focal points — the now-famous swing suspended from Colin’s field maple.

Katie said:

“Diarmuid this is giving Secret Garden vibes!”

Diarmuid replied:

“I know, you’ve found your happy place. It is amazing because Colin planted all the trees here.”

Reflecting on the maturity of the planting, Diarmuid highlighted Colin’s horticultural understanding.

“But what’s really interesting about this garden, he’s displaying an understanding of what should grow where, because in the shade of the bigger trees you have these oriental maples which absolutely love that situation.”

A sunken fern room born from lockdown

Among the standout features of the Ballymena garden is ‘The Fernery’, a dramatic sunken room that became a centrepiece of Colin’s design.

Originally conceived as a lockdown project, the space required the removal of 40 tonnes of soil.

Retaining walls were built using stone from Clinty Quarry, creating a cool, sheltered room below ground level designed specifically for moisture-loving ferns.

Colin said:

“I created a sunken room in my garden using natural stone which I’ve christened ‘The Fernery’ as ferns are one of my big passions and thrive under the tree canopy.”

Even on warm days, the below-ground room remains cool and damp — ideal growing conditions for ferns and tree ferns, which Colin says are among his most treasured plants.

“I try to grow as many things as I can myself, for instance the tree ferns - they were all raised from spores which I grew and I think there’s 13 tree ferns in the garden.

“So they’re precious to me actually and I treat them like babies; they get wrapped up every winter with a fleece. I don’t take any chances.”

Katie Piper said the feature perfectly captured Colin’s creativity.

“This shows literally the depth of his imagination.”

Borrowing the countryside beyond the fence

One of the final reveals in the garden came at the far boundary, where the design cleverly draws the eye beyond the fence line to the surrounding countryside.

Standing at the end of the garden, Katie exclaimed:

“Oh wow! Isn’t this something? Goodness me, it’s stunning.”

Carol added:

“Forget about the garden, you just feel like you’re in the countryside, don’t you?”

Diarmuid described it as a “borrowed landscape”, praising the way Colin had integrated the rural setting into the overall design.

That connection to the wider landscape is something Colin said was intentional from the outset.

“I do like formality in a garden but I also like it to be a little bit naturalistic as well.

“And I love to make the link with the countryside, so it’s not just about my garden, it’s what’s beyond that as well.”

A lifelong love of plants

Speaking to Love Ballymena, Colin reflected on how his passion for gardening began in childhood.

“My interest in plants was nurtured from a young age. My dad grew cut chrysanthemums and tomatoes in an old ramshackle glasshouse built from old window frames and doors and I still remember entering there with its distinct earthy smell.

“My mum was a keen houseplant enthusiast and used every square inch of space.

“I’ve always enjoyed being outdoors at one with nature and I’ve never lost my ‘sense of wonder’ with the natural world (as Van Morrison would say!)”

He also described the thrill of appearing on the programme.

“My most memorable moment of the Greatest Gardens BBC show experience was seeing the wonderful Carol Klein of BBC Gardeners World fame walking up my drive and meeting her for the first time in person.

“It was a thrill to be selected for the programme.”

Praise from the judges secures final place

When the judges met to decide who would progress to the final, Colin’s garden drew strong praise.

Diarmuid said:

“He had grand imagination didn’t he? I thought it was delightful, I thought HE was delightful. I thought his knowledge of plants was very good.”

Carol added:

“My impression of the garden was very much one of a person expressing themselves through using plants, and the naturalistic feel of lots of parts of it was just wonderful, I thought.”

Katie highlighted the emotional journey of the space, praising the unexpected turns and hidden rooms.

Colin’s place in next week’s final is a fitting recognition of a vision more than three decades in the making — a garden grown from bare farmland into a deeply personal sanctuary of trees, hidden pathways and quiet wonder.

For the Ballymena gardener, whose passion for plants was first nurtured in childhood and has since shaped both his career and home life, reaching the final is more than a television milestone; it is a tribute to years of imagination, patience and dedication now being celebrated across Northern Ireland.

As viewers tune in next week to see who will be crowned Greatest Garden, Colin carries with him not only the hopes of Ballymena, but the story of what can be created when love for the natural world is allowed to take root and flourish.

When to watch

Greatest Gardens With Diarmuid Gavin And Carol Klein continues Monday 20 April at 8.30pm on BBC One Northern Ireland and BBC iPlayer.

All previous episodes are available to watch now on BBC iPlayer.

The series, produced by Waddell Media for BBC Northern Ireland, sees Diarmuid Gavin and Carol Klein travel across Northern Ireland visiting 15 home gardens of varying size and style, with celebrity guests helping assess design, planting, creativity and environmental awareness.

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At a glance

• Ballymena’s Colin Agnew secured fourth place in the BBC NI Greatest Gardens final

• Colin is head gardener at Belfast’s Botanic Gardens

• His home garden has been developed over 35 years

• The site was originally farmland and a blank canvas

• Key feature includes a sunken fern room called The Fernery

• 40 tonnes of soil were removed to create the space

• Stone from Clinty Quarry was used for retaining walls

• Judges praised the garden’s mystery, levels and planting knowledge

• Katie Piper described it as having “Secret Garden vibes”

• The series continues Monday 20 April at 8.30pm