Bonsai tree: Giant redwood – Sequoiadendron giganteum

Friday, October 21, 2011

Bonsai tree: Giant redwood – Sequoiadendron giganteum

Source: Bonsai Tonight
Giant redwood – Sequoiadendron giganteum

I don’t know why it struck me so, but one of the first things I noticed about the giants in Sequoia National Park is the ground immediately around their feet. Typically, very little grew close by, and the ground was blanketed by fallen foliage. The golden-brown setting made the base of the giants stand out. It also made me wonder about the roots. Although sequoia have very shallow roots, most lived just under the surface, denying a glance at potentially impressive nebari.

The base of the trunk

Sequoia trunk in Grant Grove

No nebari

Duff at base of sequoia trunk

Many of the trees had burls or deadwood at the base, possibly signs of previous injury. The bulges below belong to the General Grant Tree.

Bulges near the roots

Trunk bulges – and a jin

On only one occasion did I notice a lot of moss growing on the bark. Said to grow up to 3′ thick, the bark is usually a cinnamon color. The tree below, however, supported a great collection of mosses.

Mossy trunk

Mossy trunk

Far more common was bark like that on the tree below.

Sequoia bark

I keep seeing an Easter Island face here

Up close, the bark is relatively smooth. Some trees have deep furrows, others are smooth all the way around.

Sequoia bark

Bark texture

Sequoia bark

With hand for scale

Tapping the bark made a hollow sound – the last thing I expected from such powerful trees, but sensible enough considering the thickness of the bark. Up above, the lowest branches were sometimes found 100-200′ from the ground. The apices weren’t exactly what we look for in bonsai, but there’s no denying the age and character they displayed.

General Grant tree apex

General Grant Tree apex

Large branch

Large branch on the Grant Tree

And all of this, from such tiny beginnings.

Sequoia cone

Sequoia cone less than 2″ long

Apparently, cones mature after 18 months but stay green and closed for up to 20 years (says the Wikipedia). Each cone contains 30-50 scales with several seeds per scale. This means a typical 2″ cone can contain over 200 seeds. Large trees can carry, say, 11,000 cones and disperse 300,000-400,000 seeds annually. Not a lot of these sprout. Scarification happens by beetle, squirrel and fire. Young saplings do best after fire when there is little competition for light.

Young sequoia

Baby sequoia

The foliage is scaly, not unlike other members of the Cupressaceae family.

Sequoia foliage

Sequoia foliage

Sequoia foliage

Foliage close-up

Young sequoia often grow close together. Sometimes they grow up that way.

Young sequoias

Thicket of young sequoia

Sequoias in close proximity

Teenage sequoia growing in close proximity

Sequoia’s massive size can help in fires that are hot enough to vaporize everything else. Thick bark and foliage high above the ground can help giant specimens survive fairly hot blazes. Throughout the Sequoia National Park, we saw evidence of recent and ongoing fires. The heat from these fires can dry and open the cones on the trees above which can then release seeds onto fertile, cleared, earth.

Fire damage

Ongoing fire damage

A large fire cleared the hillside below a few years ago which resulted in many young sequoia. This year’s fires have toasted a number of these saplings.

Young sequoias damaged by fire

More fire damage

A surprising number of the trees had similar scars, and said scars almost always appeared on the uphill side of the trunk. Any ideas why? (I don’t know the answer.)

Fire damaged sequoias

Scars from fires long past

Looking back toward a sequoia grove from the hillside with the burned saplings, I got a good look at a fairly mature tree. More than anything, the silhouette, and to a degree the color of the foliage, reminded me of eucalyptus, ubiquitous Australian trees found throughout the Bay Area. The tallest eucalyptus often grow taller than sequoia, matching the sequoia’s cousin the coast redwood, Sequoia sempervirens. I’m a fan of each of these tall varieties.

Mature sequoia

Sequoia and deep blue sky

I highly recommend a visit to the park. There are plenty of big trees to see and most are half a day’s drive from San Francisco.


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