Royal wedding florist Shane Connolly says he is treating the global event "like any other wedding".
The Belfast-born florist said the event will reflect the personalities of Prince William and Kate Middleton.
"It's not a statement of anything other than their individuality. It's completely straightforward, simple, family and good," he said.
He provided flowers for Prince Charles' wedding to Camilla Parker-Bowles and said their approach was similar.
Mr Connolly holds a Royal Warrant awarded by the Prince of Wales, which marks him as the official supplier of flowers for royal events.
Speaking about the wedding on Friday, he said: "The pressure from the world isn't important, it's what they think that's important."
Adding that Miss Middleton was a "dream client", he said: "I just want to do my best for her, and for Prince William, and that's all I want to do."
Some of the flowers for the wedding will come from Windsor Great Park and other royal estates, as well as from other growers.
The flowers and plants include blossoms, azaleas, rhododendron, euphorbias, beech, wisteria and lilac.
There will be six 20ft-high English Field Maple and two Hornbeam trees in the abbey, all growing in planters made by craftsmen at Highgrove, the Prince of Wales's residence in Gloucestershire.
The flowers and plants will remain in the abbey for public viewing until 6 May, when the trees will be taken to Highgrove Gardens for planting.
The couple intend that many of the cut plants and flowers and all the growing plants will be given to charities or re-planted.