Thanks bullet1968. Yes, i modeled them. I tried sprite trees but couldn't get the look I wanted. I made these with particles. The trunks are just cubes with extrudes.

Had some free time so I modeled a quick house scene just to test out the tree render times. Trees are efficient I believe. This only took 1 min 36 sec to render. There are 7 trees (although you can't see all the trunks) in the scene and 4 bushes.