In the Pawvillion. In the pawvillion you'll see three trees with pink apples hanging on them, you have to shake those trees for black apples (but the trees often drop regular apples, so you have to shake them a lot!)
Go to Pawvilawn. Go to the appleberry trees. Search them. You'll find them.
Go to the pawvillion, you will find purple - ish trees with normal apples in them. Keep shaking them and you will eventually get a black apple ^^
petpet plaza No they aren't liar!
Squippet Hollow is in the northeast part of Petpet Park you can find the Crafting Tree there.
In Park Pointe Square.
in bogbottom
The pawvillion
You can find him in Mystimar Glen.
Pumkin patch on your right. Wilted plant with black stuff on it. ~Nani
Grenn's Farm
He is at Laughing Spring
In the Pool of Illusion