Idaho's landscape design curriculum.
I've used it- it was a great entire curriculum that is NOT just PowerPoint based!! I also have some supplements if you're interested in additional worksheets, etc.
http://www.uidaho.edu/cals/ae4hyd/secondaryagcurriculum/ag330-landscapedesign
Do you still have this curriculum or additional activities? I tried the link but it is inactive now- thanks!