Wednesday, October 21, 2015
When trees get dressed with the colors of fall, it’s time to go shopping.
“If you’re specifically interested in fall color, it will soon be the time to start looking,” said Neil Bell, a horticulturist with Oregon State University’s Extension Service. “There are already some trees starting to display color.”
First, though, Bell recommends doing some research. Walk around neighborhoods, parks and public gardens to get ideas. If you can’t identify the trees you like, snap good photos, pick up several leaves or ask the owner for a cutting. Take them to the nursery or to your local OSU Extension office for identification. You can also cut out pictures from magazines and flip through garden books to find possibilities.
But wait, you’re not done. After filtering down your favorites, be absolutely sure about size, soil and sun requirements, Bell said. You don’t want to be stuck with a 60-foot tree where a 30-foot tree should have gone.
“The biggest problem people have,” he said, “is that a tree gets too large, and then they are forced to prune just to reduce the size of the tree, which can often look horrible. I see it all the time.”
Topping – or cutting off the tips of trees – is especially undesirable. It introduces the possibility of disease and gives pests more access. Topping also encourages weaker growth and alters the shape.
“It disfigures the tree,” Bell said. “That’s my main objection.”
Before buying, also find out if the tree needs sun or some shade and if it requires irrigation in summer. Most do, according to Bell. And most want sun, although vine maple, katsura, paperbark maple and ‘Eddie’s White Wonder’ dogwood don’t mind some shade.
Fall is an ideal time for planting, Bell added. Soil is warmer than in spring, so roots get a good head start. The weather is cool so trees are under less stress. Rains will start soon and reduce the need for watering.
“All in all, fall is the perfect time to select and plant a tree,” he said. “Wait for the leaves to start changing color and go for it.”
Here are Neil Bell’s recommendations for trees with excellent fall color:
Red maple (Acer rubrum): A common tree, but for good reason. Not much beats the vibrant scarlet color this maple displays in autumn. Make sure you’ve got room for it though; red maples grow quickly and eventually reach 60 feet tall and 25 to 35 feet wide. At that size, it makes a great shade tree.
Big-leaf maple (Acer macrophyllum): An impressive tree all around, big-leaf maple stirs up attention when its 12-inch leaves transform into a rich yellow, sometimes tinged with orange. A large tree up to 50 feet at maturity, this West Coast native is not appropriate as a street tree or in small gardens. However, if you can find it, ‘Seattle Sentinel’ is a much smaller, narrower alternative, 15 feet tall and 5 feet wide.
Vine maple (Acer circinatum): Native to the Northwest, vine maple really comes into its own in fall when the foliage lights up in lively shades of red and orange. A useful small tree up to 15 feet that often grows with multiple trunks. Good for the east side of the Cascades. Not suitable for full sun.
Paperbark maple (Acer griseum): Unmistakable cinnamon-colored peeling bark and glowing orange-red fall color make this slow-growing, small tree (25 feet eventually) a much-loved specimen in any size garden. Prefers a partially shady exposure.
‘Raywood’ ash (Fraxinus oxycarpa): Big and bold, this tree grows 60 to 70 feet tall and almost as wide, which is a consideration when deciding where and if to plant it. But if you’ve got the space, you’ll be happy with its striking claret-colored fall foliage and the equally appealing texture of the lance-shaped leaves.
Katsura (Cercidiphyllum japonicum): The unmistakable heart-shaped leaves emerge purple in the spring and seem to turn buttery yellow overnight in autumn. Falling leaves smell wonderfully like burnt sugar. The form is tall – up to 60 feet – and rounded, just how you think a tree should be.
Sourwood (Oxydendrum arboreum): A little-known, but deserving tree that has the unusual feature of sending out long streamers of fragrant, white flowers in fall just as the foliage turns to heady shades of red, orange and purple. At 25 to 30 feet tall, sourwood fits nicely into a small garden.
‘Eddie’s White Wonder’ dogwood (Cornus kousa): A spectacular cultivar of Korean dogwood that is blanketed in large, white star-shaped flowers in spring and strawberry red color in fall. Its 20-foot stature makes it ideal for small spaces. Other kousa dogwoods are outstanding as well, most turning a deep crimson-purple in autumn.
Persian ironwood (Parrotia persica): Another smaller tree (25 feet tall and 30 feet wide), ironwood is bathed in every color of the sunset in fall and has the bonus of gray and beige exfoliating bark. An easy tree to grow that handles parking strip situations nicely.
‘Wild Fire’ black gum (Nyssa sylvatica): While the straight species of black gum can be a bit weedy, newer cultivars such as ‘Wild Fire’ don’t go to seed. Glossy green leaves emerge a deep red in spring and end the season with a spectacular show of orange, yellow, scarlet and purple. Has a nice pyramidal shape and grows up to 20 feet.