Tree Talk: Redwoods — giants of the canopy

Flying into Seattle from the south, the east, or the north, everything below you is predominantly green. The houses and neighborhood business districts look like a city sprinkled into the wilderness. What you’re seeing is a World Class urban horticultural canopy and it is effective. We had a few uncomfortably hot days this summer, but for the most part, it’s been our typical Northwest coastal summer, the envy of the Northern Hemisphere. We can thank the Pacific Ocean and our position on the globe for much of it, but it’s also our vast urban canopy that shades and cools us.

Firs, Cedars, Big Leaf Maples and a wide assortment of street trees, favored in the eastern United States, make up this eclectic canopy. But around the turn of the 19th Century, a new immigrant showed up. A few intrepid gardeners planted Coast Redwoods (Sequoia sempervirens). They are the tallest of the World’s trees. Old growth specimens, in California and Southern Oregon, exceed 350 feet in height. Named for their straight, sturdy trunks covered in reddish-brown fibrous bark, these statuesque trees grow 3 to 5 feet a year until they reach 70 to 90 feet, then growth slows and they inch up over the centuries. In 30 years, they’ll have a spread of 30 feet, casting long, gentle shadows, creating an environment in which the deciduous trees near them grow wide and luxurious and we stay cooler.

The stems of foliage that look like giant feathers are made up of flat, glossy green, inch-long leaves that are gray-green on the underside. Several cultivated varieties have blue-green foliage. Redwoods are almost pest free and thrive in our rich acid soil and mild, moist climate. Towering and ancient, the great Redwood forests have survived centuries of forest fires and droughts that have plagued California, on and off, for all of recorded history. Ergo, a great choice to supplement our native flora as the Northwest climate warms and grows drier.

These behemoths are not for every garden, but if you have a large lot, a Redwood planted strategically on the south edge or in the southwest corner of your plot, will provide beauty and shade for generations to come. These Redwoods, planted and tended, are also a great gift for a garden club, or even individuals, to donate to public parks.  

Nurseries are starting to carry Redwoods. You’ll find them most often in 5- and 15-gallon cans. If you buy a plant this month, dig a generous hole, at least three times the diameter of the pot it came in. Fill the hole three times with water, allowing it to soak down into the surrounding soil.

Remove the tree from its nursery container, gently loosen the roots that have filled the nursery can as the plant grew. Place the tree in the planting hole so that the top of the soil is even with the surrounding ground level. Fill in the planting hole, adding compost if the soil is not loose and loamy. Water well, again. Continue to water, at least weekly, until seasonal rains start.     

There aren’t many mature Redwoods around, but once you spot one, you’ll never forget it. There is a majestic stand of old Redwoods, likely planted in the 1930s, in the triangle just south of the Seattle Tennis Club where 39th E  juts off and down the hill from McGilvra Boulevard. Winding up and to the northwest on Lake Washington Boulevard E, at the five point intersection, there is a large old Redwood at the center of the first curve. A grand old specimen stands next to the street at the entrance of Madrona Park. All, a glorious sight to behold.

Tucked in and through our existing flora, Redwoods may well be one of our ecological links from today to tomorrow. Make an investment in the urban canopy of our future, find a place to plant a Redwood. You’ll be adding to our richly cosmopolitan, urban horticultural canopy. And you’ll be doing our city, indeed the planet, a favor.