Tree blocks (2D) for autocad, please

[Pat Begonia]

Can anyone tell me where can I find blocks (2D) for autocad to insert trees, shrubs and other ornamental plants in my garden design? I prefer pines and other conifers,
...my cottage is near the mountains and I would like to create an alpine-like landscape, with silver firs anda little lake in the center of the garden.
But now I need the blocks for my garden design!
Thanks in advance
Pat Begonia