Step 1: Material List
a) a plastic soda bottle (empty)
b) a piece of cotton string
c) sharp knife
d) hot piece of wire to make a role in the bottle lid
e) some dirt with seeds
f) little patience.

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format.
You also have the ability to customize your PDF download.
I used two 6 liters water bottles, it means arround 4 liters of water in the bottom one and another 4 liters of earth in the other.
To fight algaes (because outdoors the rain will flow through the soil to the bottom part) I added in the bottom a few physa snails (a.k.a. "plage aquarium little snails")
Thanks.
http://www.instructables.com/id/S3XR1AGFVW21T9U/
HAPPY GARDENING!
GAiL
www.pondplantgirl.com