What people find useful can change with societal trends as well as improved genetics

Shade trees are such a presence in everyone’s daily lives in so many ways, that many different factors can influence changing trends in terms of what’s grown and what’s sold.

At home, the pandemic pushed people towards making their backyard spaces better. Rose Potter, tree and shrub buyer at Farmington Gardens (Beaverton, Oregon), has seen homeowners invest in new privacy and shade tree options. The same is true for people working with smaller residential lot sizes.

As weather patterns continue to intensify, people are also looking for trees to help the environment. “[There’s] recognition that a changing climate will require us to develop climate-resilient trees that can perform over a wide range of climates and growing conditions,” said Nancy Buley, director of communications at wholesale grower J. Frank Schmidt & Son Co. in Boring, Oregon.

Urban forests are influenced by urban planners looking to increase diversity of species. That in turn influences what developers do as they look to quickly plant trees in a newly finished property. But before trees can go in a backyard, strip mall or corporate campus, there’s the practical process of getting them to market. That also influences shade tree trends.

Farms continue to encounter labor shortages, and nurseries aren’t exempt. Growers like Brentano’s Tree Farm LLC in St. Paul, Oregon, have cut SKUs and limited the varieties they grow to suit the number of workers they have, according to owner Pete Brentano.

Media attention on new varieties can change the inventory levels of the products the end user demands.

Even with all those factors, and the possible wide variety of trees that could meet them, there is a certain consensus about which shade tree genera are trending. We talked to several industry experts about what they are seeing.

We will cover flowering shade trees in this article. We’ll then cover other shade trees without prominent flowers in a second installment, to run in a future Digger issue.

Flowering trees

Potter asked a sales rep what homeowners want most in a tree, and the answer she got was: Something that stays small and evergreen, but also flowers. If only!

Since you can’t get all those attributes in one tree, homeowners with small lots are planting just a few, compact flowering trees, according to Amy Whitworth, owner of Plan-It Earth, a landscape design firm in Portland, Oregon.

Whitworth said they prefer options with the most multi-season interest. That leads customers directly to Cornus and Magnolia.

Cornus

Dogwoods of small stature — even smaller than Cornus florida f. rubra (Pink Flowering Dogwood) — are trending wildly in garden centers, according to Potter.

“There is a lot to love about a dogwood,” Whitworth said. “It looks beautiful, and it’s an old-fashioned tree that is a classic. They are beloved, a feature of people’s childhood.”

The display of the newer disease-resistant varieties introduced by Rutgers cross Cornus kousa with native dogwood. They support the nostalgia and modern need for improved vigor.

“I don’t want to do all maples — I’m afraid they’re going to die — and I feel that about dogwood, except for the disease-resistant ones,” Whitworth said.

Constellation^® dogwood (Cornus × ‘Rutcan’; 15–25’ tall by 12–18’ wide) is a small but vigorous variety. Highly disease-resistant, it is studded with large white bracts in late spring to early summer.

Constellation^®, Celestial^® and Stellar Pink^® are top sellers among the Stellar^® series of Rutgers hybrids of C. kousa × C. florida. In 2004, Rutgers launched the Jersey Star^® series, hybrids of C. kousa with C. nuttallii that include Starlight^® (C. kousa × nuttallii ‘KN-43’ PP 16293) and Venus^® (Cornus × ‘KN30 8’ PP 16309), 15–20 feet tall and wide; Zone 5–9.

Dogwoods are rarely placed in streetside applications, but Venus may work in certain places, according to Brentano. It’s selling well to the independent garden centers, and it is also being requested for streets and parking lots.

“It has a huge flower, big as a dinner plate, which is so striking when it flowers, and it has a strong trunk with a good growth rate,” he said. “We can’t get enough of them.”

The petite Scarlet Fire^® Dogwood (Cornus kousa ‘Rutpink’; Zones 5–8), an introduction of Rutgers University, starts with a quick growth spurt of 3 feet in the first year. It slows to top out at 8 feet over 10 years. The vibrant dark pink bracts paired with drought and heat tolerance make it a sought-after plant.

Magnolia

Eric Prescott, manager at nursery retailer Farmington Gardens in Beaverton and Hillsboro, Oregon, said the Little Girl series of magnolias can be a fitting substitute for Norway maple, without getting to that size.

Customers at garden centers have been specifically asking for one of the eight different options by name: Magnolia ‘Jane’ (M. liliiflora ‘Reflorescens’ × M. stellata ‘Waterlily’, 15’ tall by up to 12’ wide; Zones 4–8). The blooms of these adaptable, very slow-growing plants show 7–10 days later than other deciduous magnolias, making ‘Jane’ less apt to be stung by late frosts.

For an evergreen magnolia for small backyards, customers ask for ‘Little Gem’ (M. grandiflora ‘Little Gem’; 15–20’ tall by 7–10’ wide Zones 6–10). It’s a slow-grower, reaching less than a foot of new growth per year and has good drought tolerance. It’s upright, multi-stemmed and produces fragrant, long-lasting 4-inch flowers after two years from mid-spring to summer. Cone-like fruiting clusters of red seeds also develop, which are attractive to wildlife.

For the columnar trend in trees, Whitworth points to the new release Alta^™ Southern Magnolia (M. grandiflora ‘TMGH’; 20’ tall by 9’ wide; Zones 6–10). It is another slow-growing evergreen variety, perfect for the combination of fitting urban plots (as it takes 10 years to mature) that boasts good fragrance and low-water needs.

For Mark Krautmann, owner at wholesale grower Heritage Seedlings and Liners in Salem, Oregon, the new evergreen Coppertallica Magnolia (Magnolia michelia foveolata × laevifolia ‘RLH-MFL-1’ Coppertallica™; 8–10’ high; Zones 6-10) fits the trend of smaller, multi-stemmed magnolias. He singles it out as distinct.

“It’s completely clad in shimmering copper fuzz beneath the leaf that lends contrast in the extreme to the shiny deep green upper leaf surface, and it has abundant, creamy white fragrant blooms,” he said. “It won’t grow in climates colder than Zone 6, but it’s a blooming spectacle, and is much smaller in stature than most magnolias. Finally, the evergreen foliage works perfectly for cut branches, either on their own, or to accent a unique floral display.”

Styrax

Keeping with the theme of small flowering plants, Japanese snowbell (Styrax japonicus; 20–30’ tall and wide; Zones 5-8), has really caught on with homeowners, according to Whitworth. She claims it is on the “Top 10” list for dwarf or flowering trees of just about every plant/garden blogger and columnist out there. It has a slightly fragrant blossom, good fall color, and is a slow grower.

Additionally, Nightfall^™ Snowbell (S. japonicus’ JFS 6SJ’ PAF.; Zones 5–10), a JFS introduction, has the snowbell flowers that contrast with dark purple leaves, a weeping structure and a compact 8-foot-tall by 6-foot-tall wide footprint.

Lagerstroemia

Figuratively and literally, Lagerstroemia check off so many boxes: fall color, blooming, come in small sizes.

“Crape myrtles are super hot,” Whitworth said. “They love the hot sun and tolerate drought once established. They used to not bloom for us [in the Pacific Northwest], but now they are in July, August and September. People are noticing them.”

The bonus for designers like Whitworth is they can be placed close to a patio. There are no bad traits of uplifting concrete or pavers, no invasive roots or debris dropped in the living space — and they are fast growing.

Potter has seen customers at the garden center come in to request a color over a specific variety. They ask for single-stem or larger specimens, which are harder to get.

Meeting the trend for dark foliage, Carl Whitcomb developed Double Dynamite^® (L. indica ‘Whit X’ PP27085, Zone 7–10). It has vibrant flowers in a cherry-red color, stays small (8–10 feet by 8–12 feet,), and never seeds so it blooms all season. It also has an exfoliating bark and is mildew resistant.

“It’s an incredible burgundy when it first leafs out,” said Nicholas Staddon, plantsman and company spokesman with Everde Growers, a large wholesale grower based in Orange, California, with nurseries in multiple states. “I had 100 days straight days of blooming in my trial plants; 100 straight days of blooming is unheard of.”

Cercis

As a wholesale grower selling to rewholesalers and landscape architects, Everde often experiences a big moment when they bring on a big tree. According to Staddon, Cercis canadensis is having that big moment — especially because of the new group with “massive improvements,” bred by Dennis Werner at North Carolina State.

“We’ve grown Flame Thrower^® in full sun, during days of 100 degrees, and there is no burning,” Staddon said. “These are improved varieties.”

Flame Thrower^® (C. canadensis’ NC2016-2’ PP31260; 15–20’ tall by 15’ wide) won first place for Plant of the Year at the 2021 Royal Horticultural Society’s (RHS) Chelsea Flower Show for its small stature and big four-season interest.

Landscape architects and retail garden centers like them because they’re not a large tree, but also because they have great branching structure and a great flower, according to Brentano.

“They have all the bells and whistles of an attractive year-round tree,” Staddon said.

Flame Thrower brightens the landscape and is relatively low maintenance, and drought- and heat-tolerant. It is considered pest-free, with attractive texture and color.

“They’re going to bring out the other tones in the landscape.” Staddon said. “Everything is winning about them.”

“It’s not going to be a street tree really quick,” Brentano said. “It won’t fill those large numbers. But, if we’re talking about doing a housing development, redbud fits with today’s backyard.”

A lot of new varieties are coming out each year. New trending varieties include Midnight Express^™ (C. canadensis ‘RNI-RCC3’ PP34213) and the dark-leafed ‘Merlot’. The weeping varieties, like the maroon-red leafed ‘Ruby Falls’ and green-leafed Lavender Twist^® (C. candadensis ‘Covey’; 5–10 feet tall by 5-10 feet wide), are trending because they are changing how people use redbuds, according to Staddon.

“You’ve got a small manageable plant that that can be used in a container,” he said. “They thrive in many areas of distribution.”

Nyssa

Tupelo trees are rising in prominence and are getting breeding attention.

“We are seeing a new variety of Nyssa coming out fairly often, and it goes with the push toward diversity,” Brentano said.

It’s been a tree that was overlooked in the past because it doesn’t do well bareroot, but that is changing as the production problems have been fixed. “Producers have figured out how to do them smaller in a root bag or pot,” he said.

With those issues out of the way and new cultivars coming on, Nyssa salvatica is a trending tree. “I think it is a worthy tree,” Brentano said. “If I would put something in my yard, I would do Nyssa for a different look.”

“They are good trees for color,” Whitworth said.

They are being released with many forms that make them easier to place in the landscape.

Buley pointed to Afterburner^® (N. s. ‘David Odom’, 35 feet by 20 feet), selected by Keith Warren, retired JFS director of product developments. JFS introduced Afterburner in 2012, and Firestarter^® (N.s. ‘JFS-red’ PP26795), 35 feet by 18 feet) in 2014.

Afterburner is a fast grower. It’s female with a central leader and a uniform habit. It has an upright pyramidal to oval shape and a fire-engine red leaf in fall.

Firestarter has a similar habit to Afterburner, but it is a male, has no fruit, and has a tighter habit. It has shinier foliage in summer and fall color that starts 10 days later.

Two newer cultivars are notable for their Zone 4 hardiness rating,  a zone hardier than most currently in the trade rated at Zone 5. Discovered in Ohio, Tupelo Tower (N.s. ‘WFH1’ PP22976, 30–40 feet by 20 feet) has an upright, narrow growth habit and lustrous dark green foliage. The broadly upright Northern Splendor^™ (N.s. ‘Twin Lakes’, 40–50 feet by 20–30 feet) cultivar originated at Twin Lakes Nursery in Grand Rapids, Michigan.

Other small flowering trees

Most of the trees mentioned so far check the box of another trend: easy care trees. Whitworth describes these as ones that don’t need much pruning or watering and don’t clog up gutters with their debris. This includes the drought tolerant ones.

“When people want really no fuss, no muss, I look toward trees with smaller leaves and fruitless ones, or ones that only drops once, or all together, Japanese maples are good that way,” she said.

“Parrotia persica (Persian ironwood, 20–40 feet high by 15–30 feet wide; Zones 5–8) is huge right now, including the new compact and narrow cultivars,” Whitworth added. They are easy to care for. “You don’t even have to start pruning for many years, if you have to prune it all.”

Plus, Parrotia has fall color and four-season interest. It comes in many sizes, and it’s easy to source. “My first answer is always Parrotia,” Whitworth said. “I love Stewartia, but it is difficult to get, and you need certain conditions to grow them.

Buley points to the cultivars ‘Vanessa’ and ‘Ruby Vase’ that are trending Parrotia cultivars for their more compact stature than the species.

“They’re very popular because of their upright, vase shape and their overall disease resistance and adaptability,” Buley said.

Persian Spire^™ (Parrotia persica ‘JFColumnar’ PP 24951) is an up-and-coming ironwood as well, she added. “[It’s] well-mannered and compact, and a good fit for our UtiliTrees^® designation,” she said. “And it originated right here in Oregon, at JLPN Nursery of Salem.”

A hybrid of two different genera within the tea family, × Gordlinia grandiflora is a superstar, according to Krautmann. It has a distinctive ability to survive under hot, dry summer conditions (including during the 117 F temperatures in Oregon during the summer 2021) and be unfazed.

The variety is remarkably drought tolerant as well, requiring little or no supplemental landscape irrigation. Few trees flower in the late summer or fall in temperate climates, but this exceptionally tough hybrid does.

Unlike its parents Franklinia and Gordonia, it’s easy to grow in a pot or the landscape. It has pure white blooms with bright golden pollen-bearing anthers at their center — just like Franklinia. It’s semi-evergreen with some red-orange leaves over a long period into the early winter in Oregon.

Second installment

In part two of this article on shade tree trends, we’ll discuss other options, including maples, columnar trees, Zelkova, natives and more, as well as looking at the increasing desire for environmental stewardship that influences what people want to plant and grow.

Tracy Ilene Miller is a freelance writer and editor who covers several topics, including gardening. She can be reached
at [email protected]