never
Mrs- Prune's Boarding House - 1915 was released on: USA: 4 December 1915
in a special plant house with a yard
http://www.unce.unr.edu/publications/files/ho/2004/sp0416.pdf#search="prune palms"
You don't own a house in this game.
You can prune it but the symmetrical shape that makes it attractive will be wrecked. If you do prune only tip prune.