The different figures you are seeing are probably mostly due to different evaluation time periods. The reasoning never has been completely clear to me, but the stated size for most nursery stock is based on certain time periods (for instance, size in 10 years) and not on the ultimate size of the plant. It would make more sense, if the time periods were quoted with the sizes, but this is not the usual practice. Conifers keep growing until they die, so count on your juniper getting much larger than 3' in diameter if it lives long.

It's fairly narrow. Monrovia Nursery seems to sell a lot/propagate these as I commonly see them in nurseries as brought in Monrovia stock.

Here's a link. I wouldn't expect it to become much wider than 4-5 feet at the base as a very old specimen.

Dax

Here is a link that might be useful: Monrovia: Spartan Juniper

more pix at link

what is your application ....

relying on only what the bigboxstore carries in bulk .. does not usually get you the best plant ... it only gets you the easiest to propagate for profit plant ....

it looks like it has a tendency toward multiple leaders ... which may or may not be a problem in your zone.. it is.. up here in snow country ...

ken

Here is a link that might be useful: link

I plan to plant them between my driveway and a brink wall. At it's narrowest point, the planting strip is about 3 feet wide, but I'm okay if the trees overlap some of the driveway as long as they don't encroach too much. I live in the city, so our lots are stacked very close, with a new two story house less than ten feet away. Some quick cover would be nice...

I did have crepe myrtles along the driveway, but they were just too messy. I thought about emerald green arborvitae, but they take along time to get tall. I also considered skyrocket juniper, but I wasn't wild about their color. Another option would be a tea olive hedge, but I do have a few of those already. I still could go that route though, since they seem happy in my yard.

Any other ideas, or would Spartan be the way to go?

Thanks gang!

The "15' tall, 3'-5' wide" Monrovia depiction you can count on being smaller than the eventual size on a good site in a suitable climate. Your 3' wide strip will be too small for such a tree. You will some day find yourself having to shear the sides, unless you have the left the site before that time comes.

"Introduced in 1961-62 by Monrovia nursery of California. Common. Fast, dense, compact narrow pyramid; to 20' tall. Foliage rich green. Berries blue, small, easily squished, single-seeded. Clearly J. scopulorum (or J. virginiana) despite being sold as J. chinensis"

-- Jacobson, North American Landscape Trees (1996, Ten Speed, Berkeley)

At 20' tall if it was only 1/4 as wide as high it would still be 5' across.