The gardening window displays will be on show for the rest of April.
The GuerrillaGardening.org group is also holding a Royal Weeding Day on April 29th.
Founder Richard Reynolds wants people wearing crowns weeding. See
And for the International Sunflower Guerrilla Gardening Day on 1 May, 1,000 have signed up. See http://www.facebook.com/event.php?eid=149256381795868