Category: Winter Horticulture Highlight

Siebold Hemlock, Tsuga sieboldii

January 29, 2019

No white nor red was ever seen

So am’rous as this lovely green

-Andrew Morrell

As leitmotif to last time’s “who does your garden grow,” we turn next to Siebold Hemlock, Tsuga sieboldii. The genus Tsuga is small with just nine to eleven species, depending on taxonomic analysis, compared with the much larger genus Pinus, or pines. All hemlocks are medium-sized to large, evergreen trees, native to North America and Asia. Previously we have reviewed Canadian hemlock, by far the most prevalent species growing at Mount Auburn.

Siebold Hemlock, Tsuga sieboldii, also referred to as Southern Japanese hemlock may reach heights of 100-feet in the wild, but more often half that tall in landscape use. They have single, flattened, needle-like leaves, each about ½-inch-long, with smooth edges and a tiny notch on the tip. The undersides have two white stomatal bands. The seed cones when ripe are pale brown, one-inch-long.


Pinus koraiensis – Korean Pine

January 3, 2018

One must have a mind of winter
To regard the frost and boughs
Of the pine-trees crusted with snow…

-Wallace Stevens

Let’s begin this new year with something positive from Korea and Russia, as well as mention of Siberian Tigers. Pines, Pinus are the largest and most diverse genus of conifers, with at least 125 species world-wide. With two-dozen diverse species of Pinus growing within Mount Auburn, herein we profile the Korean Pine, Pinus koraiensis, one of the handsomest cold-hardy pines. As the common name implies this is native to Korea, but also to parts of northeastern China, Pacific Russia, Kamchatka and on the high mountains of the Japanese island of Honshu.


Ilex opaca – American holly

November 24, 2011

Love is like the wild rose-briar,
Love is like the wild rose-briar,
Friendship like the holly-tree-
The holly is dark when the rose-briar blooms
But which will bloom most constantly?
The wild-rose briar is sweet in spring,
Its summer blossoms scent the air;
Yet wait till winter comes again
And who will call the wild-briar fair?
Then scorn the silly rose-wreath now
And deck thee with holly’s sheen,
That when December blights thy brow
He still may leave thy garland green.

-Emily Bronte

Many holiday season decorations, especially wreaths, include the leaves and fruit of Ilex opaca, American holly. Ilex opaca, native to the eastern United States, may reach 40 to 50 feet tall in its southern range, but in Massachusetts it is more often a smaller tree, 20 to 30 feet tall, with stiff evergreen leaves. The leaves, 1 ½ to 3 ½-inches long, have several sharp spine-like points along the margin. The leaves remain on branches for two to three years before being replaced by newer leaves. The name opaca means opaque or shaded, and refers to the duller sheen of the leaves and fruit compared to the English holly,Ilex aquifolium.