They are a sign that spring has finally sprung – and following unusually warm weather earlier this year, the nation’s rhododendrons are set to impress more than ever.

Organisers of the 2019 Scottish Rhododendron Festival have said this year’s event will be vibrant and full of colour from day one as many of these striking plants are already in bloom thanks to above average temperatures.

The festival, which takes place from April 1 to May 31, comprises more than 50 events north of the Border as gardens, estates and woodlands open to showcase their displays.

Returning for its fifth year, the annual event is organised by Discover Scottish Gardens and supported by VisitScotland.

It aims to encourage local audiences and tourists to enjoy the wonders of Scottish gardens during the rhododendron flowering period and highlight the diversity of collections that can be found here.

Rhododendrons are a large family of around 1,000 species from small mountain shrubs to magnificent tree-like specimens. This year, many species have been flowering earlier than usual due to higherthan-average temperatures in most parts of the country.

In February, the Met Office reported an average temperature of 6°C in the UK, which is 2.4°C above the 1981-2010 long-term average.

A southerly incursion from north Africa brought record-breaking temperatures and dry sunny weather throughout most parts of the country in the latter half of the month.

David Knott, curator at the Royal Botanic Garden Edinburgh, a world centre for rhododendron studies, said: “The warmer temperatures we have been experiencing provide optimum conditions for these exotic shrubs, originally from the east, to thrive.”

He added: “The unusual weather and early flowering also highlight the impact of climate change on plants and flowering behaviour.”

Four new venues will participate in this year’s festival including Abbotsford, Cawdor Castle, Cowden Japanese Garden and National Trust for Scotland’s Culzean Castle, with each hosting activities and Rhodo walks for all the family.

The festival was originally founded by the Glorious Gardens of Argyll and Bute. Some of the most stunning rhododendron displays can be seen in the west of Scotland at gardens including Achamore, Glenarn and Benmore Botanic Garden.

Elsewhere, Inverewe, Gordon Castle and Attadale Gardens in the north provide beautiful displays, as do the Royal Botanic Garden Edinburgh, Branklyn and Glendoick Gardens in central Scotland, and Dawyck, Glenwhan and Logan in the south.

Malcolm Roughead, VisitScotland chief executive, said: “It’s fantastic to see the Rhododendron Festival return for its fifth year.”