The apple trees are in the Pawvillon.
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 ^^
you can shake them off trees in blizzard mountain
They are in Blizzard Mountain in front of the Wintery Shoppe on a few trees.
The Petpet Plaza is found by easily looking in your map on Petpet park.
Just shake the the tree the person wants and you will get a black apple.
You can use your Neopets account for PetPet park.
Petpet Park was created in 2008-10.
They're in PetPet Plaza. They look like lanterns in the trees near the mall.Try to get the purple ones.Not the greens , reds, or any other colour.
You can find it infront of Bink's and Bonk's Lair on the Christamas trees
Go to Pawvilawn. Go to the appleberry trees. Search them. You'll find them.
At the Petpet Emporium.
You don't.