Working as garden designers or landscaper plants are the main element of focus after the design, and the more the merrier so you can have a more diversify library in your Lumion Pro.
There are a few websites with 3D plants you can purchase and use them in Lumion, they are not going to be animated do. But they work fine for rendering images, the option I use the most os the 3D Warehouse from SketchUp. Just be careful to download 3d good quality and low polygon models. The low polygon is important for the workflow speed, the heavier your model becomes working in it in Lumion is going to become slower.
Check out the images below the 3 plants you see are from the 3D Warehouse the others are from the Lumion PRO 9 library.
In this video, I show you how to get a good plant material and for free!
Check out our 3D warehouse plants, furniture and complements collections at https://3dwarehouse.sketchup.com/by/gardendesigntools?nav=collections
Check out my online courses at http://www.gardendesigntools.thinkific.com.
Go to our blog to check tips and apps suggestions https://gardendesigntools.wordpress.com/.