blocks are exclusive from pokemon diamond,pearl and platinum,so you can't get it. But you can feed pokemon with beries.
you can't...
Safari Zone in the Meadow (you need the blocks)
Catch Riolu in the Safari Zone after unlocking the blocks.
Grass blocks in pokemon heart gold are were wild pokemon hide you may catch them and train them or you may beat them with your pokemon and earn exp.
in the safie zone put 9 forest blocks 19 rock ones in the swamp
TheiR areas in which you cath pokemon for example sandslash can only be found in the DESERT block
You can find it in the safari zone in blocks and other requirements in parenthesis but only when you have got the national Dex
In the Safari zone, after getting National Dex. In the Flower Bed Area, with 10 forest blocks and 14 Rocky blocks in place. Then you wait 70 or more days.
Riolu is located in the Safari Zone, you must arrange your blocks to obtain him, they are mostly located in the Meadow area.
No where. But you can catch a Vigoroth in the safari zone by placing 10 plain and 19 forest blocks (10 Shrubbery and 19 trees) in the Peak zone
You can catch Lairon in the Safari Zone, but you need to arrange the blocks and he'll most likely be in the Peak area in the Safari Zone.
When you enter the Safari Building (where you pay the 500 Poke to get in) there should be a machine with 6 different colored dots on it. Go to it and you can customize your Safari Zones