Prince Charles Just Made a Rare Comment About Grandson Prince George

Prince Charles is giving his 5-year-old grandson Prince George a gift that keeps on giving.

The royal spoke candidly about a special present he planted for his first grandson just after his birth in July 2013 in the upcoming documentary, Prince, Son and Heir: Charles at 70.

Speaking from his arboretum at his Scottish home of Birkhall, Charles gestures to dozens of trees that were planted when the royal was born five years ago, and says: “This is George’s wood.”

“As I get older, all I really long for is to plant trees,” Charles, who has a lifelong commitment to conservation and the environment, continues. “I hope it will be quite amusing for George, as they grow up, and he grows up.”

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Charles’ wife, Camilla, Duchess of Cornwall, also appears in the documentary, adding: “You can’t believe how much it’s grown. It was tiny when it was all planted. The next thing you know, you’re being dwarfed by it.”

Charles’ son Prince Harry recently praised his dad for bringing attention to environmental issues.

While in Sydney last weekend, Harry gave a speech at the Australian Geographic Society Awards, and referred to speeches given by his father almost 50 years ago that still ring true.

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“My father and others have been speaking about the environment for decades – not basing it on fallacy or new-age hypothesis, but rooted in science and facts, and the sobering awareness of our environmental vulnerability,” said Harry. “And while those speeches would sometimes fall on deaf ears, he and others were unrelenting in their commitment to preserve the most valuable resource we have – our planet.”

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Prince Charles is about to become a grandfather for the fourth time as Harry and Meghan Markle are expecting their first child in the spring. Charles is already a proud grandfather to George, Princess Charlotte and Prince Louis.

Charles released a humorous statement after the birth of Louis in April.

“We are both so pleased at the news,” he said. “It is a great joy to have another grandchild, the only trouble is I don’t know how I am going to keep up with them.”

Prince, Son and Heir: Charles at 70, will air on November 1 on BBC One in honor of Charles’ upcoming landmark 70th birthday.

This article originally appeared on People. For more stories like this, visit people.com.