Kate Middleton, 34, was among the guests at day one of the annual exhibition, held by the Royal Horticultural Society at the Royal Hospital in London.
She was pictured looking lovely in an emerald green coat.
Kate was joined by husband Prince William at the show - marking their first-ever attendance - where they viewed a flower named in honour of their daughter Princess Charlotte, who celebrated her first birthday earlier this month.
The Princess Charlotte chrysanthemum is on display at the Chelsea Flower Show and will be available to buy at selected Waitrose stores, with some of the profits going towards the East Anglia Children's Hospices, of which Kate is patron.
This year's show is also celebrating The Queen's 90th birthday, with photographic exhibits and a floral arch, and has an incredible poppy tribute display by designer Phillip Johnson.