The spots can be found here:
* Farmland, to the right of Johnny (spot no. 1)
* Redoubt, lvl 6 dungeon (top left, above tents), last level (spot no. 2)
* Farmland, lvl 5 dungeon (with blue pumpkin at entrance), last level (spot no. 3)
* Crossroads, between the Mummers and the entrance to Hollow Oak (spot no. 4)
* Hollow Oak, first dungeon, last level (spot no. 5)
* Poison Caves, left of the entrance. (spot no. 6)
* Overgrown Path, far south, then west (next to some vines). (spot no. 7) [currently broken: no seed removed when you click this one]
* Summer Fields, lvl 27 dungeon, end of first floor, after 3rd boss battle. (spot no.
* Summer Fields, lvl 27 dungeon, after 1st hive dungeon, to the right of the Queen bee (spot no. 9)
* Summer Fields, lvl 27 dungeon, in Queen bee hive dungeon, last level (spot no. 10)
quest can't be completed as long as seed spot no. 7 is bugged