Earth Hour 2011

To ensure the spike was completely environmentally-friendly, the agency partnered with printer STI Lilyfield to invent an organic printer's ink containing natural plant fertilizer derived from Durvillaea potatorum and extract of Ascophyllum nodosum (harvested sustainably), to promote healthy plant growth and improve resistance to insect and fungal attack. Printed on 100% FSC-certified paper, this ink fertilized the pot plants as the spike biodegraded naturally in the plant's soil.
2009
Earth Hour 2009 was from 8:30 p.m. to 9:30 p.m. local time, March 28, 2009. 88 countries and 4,159 cities participated in Earth Hour 2009, ten times more cities than Earth Hour 2008 had (2008 saw 400 cities participate). One billion votes was the stated aim for Earth Hour 2009, in the context of the pivotal 2009 United Nations Climate Change Conference.