Buy the incense from the flower shop in Lapis. Budew should be walking on top of the walls in between the Lapis and Periodot Wards directly behind the flower shop. I could only get him by going to the Peridot side. I don't think weather should be an issue.
So after I found the Itemfinder, I spent a good bit of time spamming the shift key hunting for hidden items. Let me tell you. There are A LOT of hidden items all over the place. It is well worth your investment. I found a ton of heart scales and shards that I feel like I don't have to mine for them again (not like I mined for heart scales anyway). I even managed to find a black sludge along the way (to me that's really convenient).
I've searched most places, but it is a time consuming process. I'd just like to know if any of you found a pretty solid item from using the Itemfinder. I may have well could have missed a pretty cool item.
But seriously.... I can't find this drug obsessed woman to get Chespin.... I'm pretty sure I've talked to everyone in 7th Street...
Edit: Also, I get the feeling that the data chip may have more than one use just like the soul candle.... any thoughts?
The maze took a little time to figure out, but it wasn't difficult. The last guy in the maze was definitely the hardest to get by. I had to soft reset several times just to time it right, but I was running a speedhack so that may have been why.
I found the Oddishweed. Have no idea what its for as of now. But when I was trying to get it a couple times, I kept getting t a script error when "leaving the area". The only way I was able to get out of this error was to use teleport.
For grass, try Lilligant or Venusaur. And now that Chespin is obtainable as of episode 11, a Chesnaught may be useful as well.
For electric, you could try Luxray like what tempest said, or maybe even Rotom.