Bizzy in Boston

[Almisa]

Couldn’t believe my eyes for sale at a nursery here in zone 5b while visiting. My sister bought it for her expansive garden but I told her it will likely need to come inside before the end of fall because 30 degree days are common then. Thoughts?

[PalmatierMeg]

Bismarckia can survive lows down to mid-20sF but will suffer foliar damage. If your sister plants hers in zone 5b she better prepare to protect it with supplemental heat. If she leaves it potted she should move it inside when lows fall below 30F. Tell her that Bizzies hate pots and grow deep roots. Any pot she puts it in should be very deep to accommodate those roots. Finally, she should understand Bizzies are notoriously root sensitive. She should not break, cut or rough up those roots or she risks killing it. When I planted my Bizzies way back when I carefully cut their pots into pieces, then eased them off the rootball while holding my breath. If they'd been in ceramic pots I would have broken the pot before I'd risk the palm.

I see she is in Boston. I've never been to Boston in winter but my son visited once in Feb. and almost froze to death - "Mom, I've never been so cold." He was used to No VA winters. No palm can survive winter outside in MA without serious protection and supplemental heat.

[Almisa]

Meg,

Perfect information about the roots and potting. Thank you so much. She is taking it to a bright sunny office and was contemplating exactly this. Done! it will be an interesting experiment. 

[Meangreen94z]

Keeping it in a container will slow it down but they become monsters relatively quick. In a container mid 20’s is probably correct, if that. In ground a few survived mid teens in Houston in 2021. We wrapped Christmas lights around the base and then a tarp of the one in my parents yard in Pearland , Texas. It has come back from 14°F in February 2021 and 16-17°F in December 2022. The two coldest winters in over 30 years.