Start by creating a new document 2x2 pixels




Zoom in and choose the pencil tool and fill the bottom 2 pixels in.



Then go to Edit > Define Pattern and save as Grid



Now creat a new document with the settings 468x60



Fill the box with green and hit Edit > Fill or Shift+F5, Choose the use as "Pattern"
and where it says "Custom Pattern", find the one you made earlier.



Now chose the Brush tool, and at the top chose the brush that is the leaves. and have it size 68 and fill the box with black leaves.



Go to Filter > Render > Fibers and have the Variance 18.0m and the Strength 1.0. hit OK. You should get something like this




Heres my finished product.






Hope that was easy!