BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden on March 10, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)

BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden
on March 10, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)

BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden on March 10, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)

BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden
on March 10, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)

BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden on March 08, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)

BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden
on March 08, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)

BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden on March 08, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)

BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden
on March 08, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)

BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden on March 10, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)

BREDA, NETHERLANDS - MARCH 10 : King Willem-Alexander of the Netherlands volunteering for NL Doet in the neighborhood garden
on March 10, 2017 in Breda, Netherlands. NL Doet is a National Volunteer day organized by the Oranje Fonds, the King and the Queen are patron and patroness of the foundation. (Photo by Patrick van Katwijk/Getty Images)