Therefore, its known narrative elements are not a part of the Doctor Who universe. It may have been the basis for a similar story in another medium, however — and that story may indeed be a part of the DWU.
The Imps was an unproduced Second Doctor serial written by William Emms. It would have featured imp-like aliens and vegetables which attempted to destroy a space station. It had to be rewritten to accommodate Jamie McCrimmon. Emms became sick and had to rewrite again to feature the loss of Ben Jackson and Polly. He eventually gave up and The Faceless Ones was written as a departure story for Ben and Polly.