I got a scene with the ground has lots of hills and valleys. But the grass just get planted at z=0.
I selected the ground save it as a terrain that didn't work as it didn't save anything.
So how do you tell the grass where to land? or How to I prep the ground for grass to land on it?

As you did ... make that ground object a Terrain then be sure to turn off "Use Bounding Mesh" under the Modify tab for that object.
As well If you're using and old Mesh Medium terrain be sure to turn off "Use Bounding Mesh". That should get you there.



Click here to go to my YouTube Channel filled with iClone Tutes and Silly Stuff

Visit ANIMATED PROJECTIONS Powered by iCLONE

Intel Core i7 3960X @ 3300MHz Overclocked to 4999.7 MHz Sandy Bridge 24.0GB DDR3 @ 833MHz Graphic Display HP ZR30w 
GeForce GTX 980Ti 6GB  Microsoft Windows 7 Professional 64-bit SP1 ASUSTeK COMPUTER INC. P9X79 WS (LGA2011)

I just forgot that it's right click on the prop >Convert to Terrain helping me out brought it all back. Thanks for that.

Here have a free desktop on me:

Cool!


Click here to go to my YouTube Channel filled with iClone Tutes and Silly Stuff

Visit ANIMATED PROJECTIONS Powered by iCLONE

Intel Core i7 3960X @ 3300MHz Overclocked to 4999.7 MHz Sandy Bridge 24.0GB DDR3 @ 833MHz Graphic Display HP ZR30w 
GeForce GTX 980Ti 6GB  Microsoft Windows 7 Professional 64-bit SP1 ASUSTeK COMPUTER INC. P9X79 WS (LGA2011)

That was a premature celebration.
Right click on prop>Convert to Terrain
Unchecked: Use Bounding Mesh
Then I started gardening and as seen here the grass is under the terrain. 
What am I doing wrong?

Ya got me! I have noticed, when planting trees, that it isn't always as accurate as I would like. But not sure about your situation..Hopefully someone much smarted than me will weigh in!    It shouldn't harm anything though...



Click here to go to my YouTube Channel filled with iClone Tutes and Silly Stuff

Visit ANIMATED PROJECTIONS Powered by iCLONE

Intel Core i7 3960X @ 3300MHz Overclocked to 4999.7 MHz Sandy Bridge 24.0GB DDR3 @ 833MHz Graphic Display HP ZR30w 
GeForce GTX 980Ti 6GB  Microsoft Windows 7 Professional 64-bit SP1 ASUSTeK COMPUTER INC. P9X79 WS (LGA2011)

I have had the same issue lately, trees are planted kilometers above ground, no idea why

I have the answer!

The reason a terrain doesn't work is when it is anything other than a plane. I took the road as separate piece of mesh and combined it with the plane as the landscape and made it into one piece/prop. If it's anything other than a plane with lumps or not, it messes with the terrain function.
So I made prop1 landscape and the road as a separate prop, problem solved.