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Friday - April 05, 2013

From: Blythewood, SC
Region: Southeast
Topic: Non-Natives, Planting, Shrubs, Trees
Title: Space between trees from Blythewood SC
Answered by: Barbara Medford

QUESTION:

I'm planting 4 green giants in a back corner of my yard. I also have a kumquat tree to plant. I have somewhat limited space. What is the minimum spacing between the four green giants and the green giants and the kumquat. It is mostly sunny area with sandy soil. Also want to plant zho Zhou loropetelums in this plan and want to make sure they are far enough from both kumquat and green giants. I know all of these get larger and want them to help with privacy. Thanks.

ANSWER:

The Lady Bird Johnson Wildflower Center, home of Mr. Smarty Plants, is committed to the growth, propagation and protection of plants native not only to North America but to the area in which te grow naturally. Every single plant you asked us about is non-native to North America and therefore out of our area of expertise. We will try to find information from other sources to help you, but cannot guarantee that any of the plants you have chosen will do well in Fairland and Richland Counties, South Carolina.

First, Thuja 'Green Giant." Reading that link will tell you that it is a hybrid, Thuja standishii x plicata. Thuja plicata (Western arborvitae) is native to North America. When you follow that plant link, you will learn that its size range is 72 to 100 ft. tall and it has a slow to medium growth rate, is susceptible to bagworm and heart rot, and is pH adaptable.

Thuja standishii (Japanese arborvitae) is native to Japan. Japanese arborvitae is a small to medium evergreen conifer that is native to subalpine forests on the Japanese islands of Honshu and Shikoku. In cultivation, it typically grows to 20-30' tall with a broad-pyramidal crown, slender trunk, fibrous reddish-brown bark and aromatic (lemony) scale-like leaves in flattened sprays. Leaves are bright green above and glaucous beneath. In their native environment, these arborvitaes may grow to as much as 100' tall.

From the article on Thuja 'Green Giant from the U.S. National Arboretum we learned this about its growth pattern: "Height and width:To 60 feet tall with a 12–20 foot spread atmaturity; 30 feet at 30 years. Growth rate: Rapid. Habit:Tightly pyramidal to conical evergreen tree; uniform appearance."

So, we are trying to figure out what is the growth pattern for a combination of one native and one non-native Thuja to forecast how they should be spaced. Actually, while Thuja plicata (Western arborvitae) is native to North America, it is NOT native to South Carolina, according to this USDA Plant Profile Map. This leaves us with a lot of unknowns in the future of your trees.

From About.com Landscaping 10 Bad Things We Do To Our Trees, please note especially Bad Thing No. 8 Tree Roots Need More Respect. These are apparently potentially HUGE trees, and you are planting them all in a corner in your back yard. Try this University of Florida Spacing Between Trees and see if that helps you.

Next, from Purdue Univesity, an article about size and management of Kumquat. This plant was in cultivation centuries before the recorded settlements in North America and is believe to be native to China.

Oh, yes, we nearly forgot about the lorapetalum. Follow that link to this article from Clemson University, where we found this information:

"Loropetalum chinense is an evergreen shrub that generally grows to a height of 10 to 15 feet with a similar to somewhat smaller width. However, it is capable of greater height as evidenced by the 100-year-old specimens in Aiken that are 35 feet tall. It has a loose, slightly open habit and a roughly rounded to vase-shaped form with a medium-fine texture."

"Chinense," of course, means originating in China.