The problem of the correct naming of 'Shimpaku' juniper has been solved, for the moment at least. I and Iris Cohen, who is the most knowledgeable taxonomist on the IBC, often consult on correct plant names. According to Iris there was recently a meeting of the official poobahs and many of the Juniperus x media cultivars were renamed AGAIN as Juniperus chinensis. So, the current current name is Juniperus chinensis 'Shimpaku'. The "Juniperus chinensis" part of the name should be italicized.
'Shimpaku' is often confused with Juniperus sargentii, but to the best of my knowledge, these are two distinct species, although there is a good chance they are mixed up in the nursery trade. I have several J.c. 'Glauca' and it is superficially similar to 'Shimpaku', but it is a bit more blue and the growth habit is slightly different.
Brent
EvergreenGardenworks.com
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