Sequoia sempervirens, USA's widest & tallest species / ID / care

[M.D. Vaden]

Decided tp post in Arborist 101 since the post interjects some tree ID and tree care comments. As of 2015, coast redwood was found to be both widest and tallest tree species in the USA. References are very few, but the measuring was reliable and basically etched in stone factually. Here's a page that includes the diameter discovery. https://mdvaden.com/photoblog/2017/08/04/coast-redwood-the-new-giant-sequoia/

The diameter champ hasn't been published in photos. But the 27' to 28' dbh coast redwood below gives an idea what trunk girth is like surpassing 29 ft. dbh. I'm going to add a couple more replies below about foliage identification of coast redwood because the foliage of older ones can resemble that of Sequoiadendron.

I've heard lots of mantra about redwoods needing "FOG" and lots of rain to survive. But that's not fully true. The species can grow great size and height in coastal regions, but in a near record driest growing season recently, the tallest redwood in the world grew 4 years worth of height gain in a single driest growing season. And there was minimal fog. They do not need fog to grow good .. and I'm relating to big garden and landscape areas. We live in Medford. The coast redwoods here don't thrive in heat, but they can grow reasonable well. We've seen temps down to 15 degrees F and up to 115 degrees F the past few years. And most of the redwoods in reasonable soil conditions maintained color and continued to grow. We don't get summer fog. So I knew from experience that coast redwood grew good in places like Portland, Oregon. But was surprised to see they could take the conditions in Medford.

It may be worth adding that Sequoiadendron can grow good in southern Oregon near here too. A couple years ago, we found a new world's tallest planted (non-indigenous) Sequoiadendron east of Medford, and it's now 214 feet tall. And best we can tell, that's in 90 to 100 years.

 

[M.D. Vaden]

Next, foliage. If a suspected redwood has flat ranked needles and small cones, it's most likely a coast redwood. Assuming it's not the deciduous dawn redwood that also turns color in autumn.

From a distance, some coast redwood can develop a somewhat spire form like Sequoiadendon. Not many, but it's possible. There's a huge example near Hiouch, CA, in a residential front yard. It literally takes pulling over and parking, to walk over and look at the foliage and needles.

With so many redwoods in cities now, there will be more bigger ones than ever before. With older age and greater height, coast redwood can form a couple looks of foliage. This may be helpful just so someone realizes there isn't a 4th species of redwood or that it's not some particular cultivar.

 

[M.D. Vaden]

Some people say that Sequoidendron don't taper, but coast redwood trunks do taper. But both species can develop both ways. Some readers here probably know that from their years around trees. Here's a coast redwood that not only lacks taper, but may even have reverse taper. Two people for scale near the base.