Millions of phone thrown away could be trees. The seed germinates as soon it comes into contact with water. This takes a while because the biodegradable protection capsule needs to degenerate a bit and allow the water to enter. Just plant your mobile phone upright, covered with soil, no more than 2 cm deep. Keep it well-watered for four weeks until it sprouts. Then care for it as you would with any plant. Link.