Foliage on curved landscape

Hello!

Im trying to create an atmospheric forest but foliage tool doesn’t let me paint on curved landscape parts, like the hill-side, furhermore can i make the tool to stop rotating to the surface? Because the trees are leaning if they placed on non flat place. could someone help me with these?
Thanks

Look into your foliage’s “Ground Slope Angle”. The default is 45 degrees and if the slope of the landscape is higher than your max angle, you wont be able to paint on it.

https://forums.unrealengine.com/attachment.php?attachmentid=92244&d=1462625909