More than 800,000 plants will be sold over the next five days at the Bord Bia Bloom show in the Phoenix Park in Dublin.
25 different gardens will compete in the ninth annual event, with up to 100,000 people expected at the show which opens tomorrow.
The largest garden on show is from Crumlin Children's Hospital.
"It's a tranquil place, lots of semi-mature trees [and] water," said Kieran Dunne from Kildare Growers describes it, "we even have a little wren nesting in our garden since we started to build it three weeks ago."
The festival runs from May 28 – June 1, from 9am to 6pm each day. Details and ticket prices are available at bloominthepark.com