First off, you have to complete your Pokedex and get the Poke Radar. Once you've got that, go to route 218 and use the radar. Ditto will only appear on grass spots that shake and give off a yellow signal that looks like this:\l/ good luck!
Unfortunately, a Ditto appearing in Pokemon Platinum is not dependent on time of day. The only area they appear in is the Trophy Garden behind the Pokemon Mansion on Route 212, and they are part of many Pokemon species that are not native to Sinnoh that can be caught there. In order to catch a Ditto, you must talk to Mr. Backlot at the Mansion, and if he mentions that he discovered Ditto in his backyard, there will be Ditto availabe to catch in the Trophy Garden. NOTE: The Ditto, along with the other 'special' Pokemon that appear in the Trophy Garden, do not appear until you have obtained the National Pokedex.
You can migrate or catch one from a swarm or trade.
you can find ditto in the trophy garden or trade from the GTS
to find a ditto go to the route beside canalave and use the pokeradar. to find one shiny look for a different color grass spot.
to breed a Pokemon, you must catch a ditto in a patch of grass to the right of canaclave. then walk 50 steps and use your pokeradar( you need to get your national pokedex first) and keep on looking for ditto. it should be easy to catch at lvl 29... then you put the ditto and the desired Pokemon in the day care and wait for a while. then on your pokething you should see an egg. hope that helps! Doesn't work on legendaries!
There are 12 starter babies in the Pokemon World To Get Bulbasaur Catch Ivysaur and a Ditto To Get Charmander Catch Charmeleon and a Ditto To Get Squirtle Catch Wartortle and a Ditto To Get Chikorita Catch Bayleef and a Ditto To Get Cyndaquil Catch Quilava and a Ditto To Get Totodile Catch Croconaw and a Ditto To Get Treecko Catch Grovyle and a Ditto To Get Torchic Catch Combusken and a Ditto To Get Mudkip Catch Marshtomp and a Ditto To Get Turtwig Catch Grotle and a Ditto To Get Chimchar Catch Monferno and a Ditto To Get Piplup Catch Prinplup and a Ditto
You can catch Ditto at route 218. Ditto around there are usually lv 30. :)
no ditto is there
you can catch a Ditto if you talk to Backlot every day for a long time. He will say that he saw a ditto there. Then, you can catch a ditto in the trophy garden.
you cant catch ditto in the safari zone...you catch him in the Pokemon mansion in cinnabar
You can catch Ditto in the wild at The Great Chasm.
You must get ditto from emerald, firered or leafgreen because you can't catch it.
You can't catch Ditto in Ruby. You have to trade it from Emerald, Fire Red, or Leaf Green.
You can't catch a ditto in Pokemon Sapphire, but you can trade it from Pokemon Emerald/FireRed/LeafGreen.
in the pokemon mansion lvl 30 ditto
you can catch it in giant chasem
Impossible