Question #1: When can Boston ferns be put outside? How cold a temperature can they tolerate?
Answer: Boston ferns are a tropical or indoor plant and are not tolerant of any frosts or freezes and thus should not be placed outside until all danger of frosts or freezes are past. If you wanted to wait until after May 1 you should be relatively safe depending on which part of the state you live in.
********************************************************************************************************************************* Question #2: Are "fishtail ferns" perennials in Oklahoma?
Answer: No, fishtail fern (Nephrolepis biserrata cv. 'Furcans') is considered tropical and would not survive our winters here in Oklahoma. It is often used as a fern for indoor use.
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