San Jose Juniper

Can anyone tell me anything about the origin of this cultivar? How can you tell it from Shimpaku?
Iris

bonsaisr wrote:Can anyone tell me anything about the origin of this cultivar? How can you tell it from Shimpaku?
Iris

The Boon County Arboretum says:  "Cultivar selected in San Jose, CA. 1935."  I assume it originated as a creeping sport, and was propagated by cuttings.  

The arboretum also says: "FEMALE plant. Creeping form, spreads irregularly; foliage sage green. Species is toughest of evergreen landscape plants grown in all parts of the U.S.; no limit to their landscape value as screens, hedges, windbreaks, ground covers, foundation plants."

That reads as if all SJ junipers are female.  

Floridata makes the interesting comment:  

"Either Juniperus chinensis is an extremely variable species or there are actually more than one biological species (and a few hybrids as well) included under the name. Several recent authors tend toward the second opinion, and many of the shrubby cultivars with foliage that smells sour-acrid (including 'Pfitzeriana') are now listed as selections of J. X media, a hybrid between Chinese juniper and savin juniper (J. sabina), which is a shrub - not a tree - in the wild. Also, Sargent juniper (formerly J. chinensis var. sargentii), and its many cultivars, are now considered by most authorities to be a species (J. sargentii) distinct from Chinese juniper."

So it could actually be something other than J. chinensis.  ALL references I saw noted that it was extremely susceptible to Juniper blight -- apparently more than other 'cultivars.'

I suspect this wasn't very useful, but it was fun scanning my list of plant databases.

My San Jose is a lighter green as compared to shimpaku and prefers to have needle instead of scale foliage. The foliage is more coarse, imo. If you ever have the two side by side, it will be easy to tell them apart.

If you cut too much off or stress them in any way they will produce a bunch of needle "juvenile" growth. 2 years on and it's just pushing about 20% scale foliage. Go slow and reduce gradually.

Contrary to Jim's 'creeping' description it doesn't seem to be particularly prostrate, forms strong trunks.
I treat mine as a needle juniper rather than scale, foliage tends to remain immature.
Bark seems more flaky than Shimpaku.

Not MY description. ALL the references noted the creeping form. You might double check the identity of your tree.

JimLewis wrote: "Cultivar selected in San Jose, CA. 1935."  I assume it originated as a creeping sport, and was propagated by cuttings.  
The arboretum also says: "FEMALE plant. Creeping form, spreads irregularly; foliage sage green. Species is toughest of evergreen landscape plants grown in all parts of the U.S.; no limit to their landscape value as screens, hedges, windbreaks, ground covers, foundation plants."
That reads as if all SJ junipers are female.  

Read your first line again. The definition of a cultivar is a population all of whom are genetically identical, like identical twins. Among dioecious plants (male & female flowers on separate plants), vegetatively propagated cultivars are always the same sex.

JimLewis wrote: Floridata makes the interesting comment:  
"[b]Either Juniperus chinensis is an extremely variable species or there are actually more than one biological species (and a few hybrids as well) included under the name. Several recent authors tend toward the second opinion, and many of the shrubby cultivars with foliage that smells sour-acrid (including 'Pfitzeriana') are now listed as selections of J. X media, a hybrid between Chinese juniper and savin juniper (J. sabina), which is a shrub - not a tree - in the wild. Also, Sargent juniper (formerly J. chinensis var. sargentii), and its many cultivars, are now considered by most authorities to be a species (J. sargentii) distinct from Chinese juniper."

This information is incorrect. The Pfitzer junipers are now classified under J. xpfitzeriana (chinensis x sabina). Sargent's juniper is still classified as a variety of J. chinensis, but there is some question whether all Shimpaku junipers are J. chinensis v. sargentii. Bill V. insists that all Shimpakus propagated in the US are, but an RHS botanist told me they found some Shimpakus in UK that were J. chinensis var. chinensis.

JimLewis wrote: So it could actually be something other than J. chinensis.  ALL references I saw noted that it was extremely susceptible to Juniper blight -- apparently more than other cultivars.

I don't think there is any doubt that 'San Jose' is a cultivar of J. chinensis.