Duchess Kate dons floral Prada frock to visit Princess Diana's memorial garden on the eve of her 20th death anniversary

Marah Alindogan

Duchess Kate, alongside Prince Harry and Prince William, paid tribute to her mother-in-law Princess Diana with a visit to her memorial garden at Kensington Palace on the eve of her 20th death anniversary.

The trio took a rainy stroll through the White Garden on Wednesday afternoon, and the Duchess of Cambridge stunned in a floral frock appropriate for the event paying tribute to Diana.

The mother to Princess Charlotte and Prince George donned a long-sleeved Prada dress that hit just above her knee with an eye-catching teal and orange floral pattern. She completed the sophisticated look with a pair of pointy nude pumps and no other accessories.

Duchess Kate styled her shorter hair, a look that she debuted earlier in the summer, in her signature blowout style. As for her makeup, the princess kept it simple with a smokey eye and a small sweep of blush on her cheeks.

Harry, William and Kate were photographed walking and talking in the garden, which has been planted with Princess Diana's favorite flowers. A team of six gardeners and a number of volunteers spent 18 weeks planting white roses, white Diana tulips, white hyacinth, forget-me-nots and other favorites of Diana in the garden back in April. Back in July, flowers with a different bloom -- including classic English white roses and Cosmos daisies -- were planted.

A Kensington Palace spokeswoman said the royals' garden visit on Wednesday would "allow the princes to pay tribute to the life and work of their mother the day before the 20th anniversary of her death."

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Tomorrow, August 31, marks the 20th death anniversary of Princess Diana following a tragic car crash in Paris. In the months leading up this somber day, her sons, Harry and William, have spoken openly about her death.

In an HBO documentary that debuted in July, Harry and William got candid about their late mother's parenting style, calling Diana one of the "naughtiest parents."

"She was very informal and really enjoyed the laughter and the fun," 35-year-old William added. "She understood that there was a real life outside of Palace walls."

"She was our mum. She still is our mum. And of course, as a son I would say this, she was the best mum in the world," Harry said. "She smothered us with love, that's for sure."

For more on Princess Di's 20th death anniversary, watch the video above.