From 28 May until 5 June, gardens at Anglesey, Conwy, Gwynedd, Powys and Wrexham will throw open their gates to thousands of visitors during the first ever Festival of Gardens North Wales.
A packed programme of events will be staged at various gardens as the festival unfolds.
With more than 20 million gardeners in Britain, the drive to bring the growing garden army to the region is being mounted by North Wales Tourism, who believe the festival has huge potential.
The horticultural market is worth £5bn annually – more than UK people spend on chocolate.
The festival will be officially opened at a ticket-only event, with limited numbers, at the Plas Cadnant Hidden Gardens in Anglesey by celebrity gardener and broadcaster Roy Lancaster.
North Wales Tourism managing director Jim Jones said: "North Wales has some of the most stunning gardens in the UK and this event is all about bringing them together and showing them off to as many people as possible."
More than 100 unique events are planned over the nine days of the festival. The event coincides with late-spring flowering displays, which will include rhododendrons, azaleas, magnolias, tulips and flowering cherriea.
Mr Jones added: "North Wales has some of the most stunning gardens in the whole of the UK, run by a diverse range of organisations including the National Trust and a variety of private owners, with whom we have been collaborating closely to organise this very special event.
"Our aim with the festival, which will be the largest and a most ambitious of its kind ever seen in the region, is to bring them all together under the banner of North Wales.
"The festival has been extensively marketed and we expect to attract thousands of visitors not just from around the gardens but also from a much wider area, including other parts of Wales as well as the North West and Midlands of England."
Co-ordinating the festival is North Wales based gardens expert Tony Russell, who put the Westonbirt Arboretum in Gloucestershire on the international tourism map.
He said: "I do lots of work encouraging people to visit gardens across the UK and find that although lots of people are familiar with those in places like Cornwall or Kent, they don't know too much about the ones in North Wales.
"They know about the region's other attractions such as castles, steam railways, mountains and coastlines but not our gardens, which are some of the finest in the UK.
"With the festival our aim is to wave the flag for North Wales's fantastic gardens.
"The thing about the gardens we are featuring is that they are all set in such a great landscape and because of the conditions we enjoy they contain varieties plants that can't be found in lots of other areas of the UK.
"We're blessed with the three things that make the difference – plenty of moisture due to the closeness of the coast, mild winters and acid soil.
"That means plants such as agapanthus, magnolias and camellias, which usually grow up in more exotic parts of the world like South Africa, flourish in North Wales.
"Gardens are also big business now, with 30 million day visits being made to gardens across the UK every year. And of the 30 million overseas visitors coming to Britain annually 11 million visit a garden."
Anthony Tavernor, owner of Plas Cadnant in Menai Bridge, Angeley, is delighted to be taking part in the festival.
His famous walled garden took a severe battering from floods which hit the area last December, washing away a 200-year-old wall and rare plants.
But Tavernor, who has been restoring the gardens for 20 years, said repair work was currently well in hand.
"Things are going full steam ahead and there are lots of things going on to get the gardens restored," he explained.
"We're giving our full support to the festival and are delighted to have the launch here on May 28.
"The aim is to establish North Wales are a place to visit a range of beautiful gardens and to show people that we have some of the best in the UK because of our good growing conditions."
Plas Brondanw at Penrhyndeudraeth
Crug Farm Plants near Caernarfon
Plas yn Rhiw in Pwllheli
Plan Tan y Blwch in Blaenau Ffestiniog
Caerau Uchaf Gardens in Bala
Portmeirion in Penrhyndeudraeth
Aber Arto Hall in Llanbedr
Penrhyn Castle in Llandegai
Nanharon in Pwllheli (via its website only).
Plas Newydd in Llanfairpwll
Plas Cadnant in Menai Bridge.
Bodnant at Tal y Cafn
Gwydir Castle at Llanrwst
The Welsh Mountain Zoo's gardens in Colwyn Bay
The Conwy Valley Maze at Dolgarog
Gregynog at Newtown
The Centre for Alternative Technology at Machynlleth
The Dingle Garden near Welshpool
National Trust Erddig.