sky pencil holly in denver?

Asked November 20, 2020, 11:58 AM EST

How do Sky Pencil Hollys do in Denver?

Arapahoe County Colorado

1 Response

Hello,
Sky Pencil is a cultivar of the Japanese Holly (Ilex crenata) species. Unfortunately, they're very different from Colorado's native species of holly, Mahonia repens.
According to Missouri Botanical Garden's website - https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=v890 - this type of holly does best in "light, moist, acidic soils with good drainage." The clay soils in many of Denver's suburbs are the opposite of that.
Also, "May not be reliably winter hardy throughout USDA Zone 5 where it should be grown in a protected location with a winter mulch." You might be able to grow one in a protected, shaded location in an older, established Denver neighborhood. I would not try one in the suburbs that are further out or at a higher elevation, where wind exposure and lower temps are an issue.
I hope this helps with your decision.