Top Ten Trees and Shrubs with Great Fall Color

 

Sugar maple (Acer saccharum) in full fall color
Sugar maple (Acer saccharum) in full fall color

As promised in my Sept. 9 post of “The Science Behind Fall Color”, I would address trees and shrubs with outstanding fall color. It was hard limiting it to only ten trees and ten shrubs, since I found 5 common shrub species of maples alone, so I cheated a bit and grouped the maples, oaks, etc. into one group so that my list was not entirely all maples.

'Robin Hill' apple serviceberry (Amelanchier x grandiflora 'Robin Hill')
‘Robin Hill’ apple serviceberry (Amelanchier x grandiflora ‘Robin Hill’)

I have seen the below plants with reliable fall color in northern, southern and eastern landscapes. These plants “light” up the landscape in autumn. For outstanding, long lasting autumn color, plant the below trees and shrubs with herbaceous plants which bloom in fall such as asters, mums, sedums, monkshood, toad lilies, and Japanese anemones. Do not forget ornamental grasses with their showy seed heads extending the season of color and texture.

Sweet birch, cherry birch (Betula lenta)
Sweet birch, cherry birch (Betula lenta)

We used to recommend ash for fall color, but not any more due to emerald ash borer. Japanese barberry and burningbush are tops for fall color, but both species are highly invasive and not recommended. There are more plants with great fall color than the ones below. I would love to hear your favorites!

 

Top 10 Trees for Fall Color

1) Black gum, sour gum, tupelo (Nyssa sylvatica), orange-red, scarlet to purple, outstanding

Black gum, sour gum, tupelo (Nyssa sylvatica)
Black gum, sour gum, tupelo (Nyssa sylvatica)

2) Maples, especially:

Sugar maple (Acer saccharum), bright yellow to orange-red

Red maple (A. rubrum), yellow, orange-red to bright red

Freeman maple (A. × freemanii), yellow, orange-red, red to reddish-purple

Paperbark maple (A. griseum), dark red to bronze

Japanese maple (A. palmatum), orange, red to purplish-red

Korean maple (A. pseudosieboldianum), deep orange to reddish-purple

Three-flower maple (A. triflorum), orange

Full moon maple (A. japonicum), yellow-orange to scarlet-red

Moosewood, striped-bark maple (A. pensylvanicum), bright yellow

3) Ginkgo (Ginkgo biloba), bright golden-yellow

4) Thornless honeylocust (Gleditsia triacanthos f. inermis), bright golden-yellow

5) Quaking aspen, trembling aspen (Populus tremuloides), bright yellow

6) Oaks, especially:

White oak (Quercus alba), dark red to wine

Red oak (Q. rubra), red to russet

Scarlet oak (Q. coccinea), red to scarlet

Black oak (Q. velutina), dark red

Scarlet oak (Quercus coccinea)
Scarlet oak (Quercus coccinea)

7) Apple serviceberry (Amelanchier × grandiflora), yellowish-orange to red

8) Buckeyes, especially:

Yellow buckeye (Aesculus flava), golden-yellow to orange

‘Autumn Splendor’ buckeye (A. × arnoldiana ‘Autumn Splendor’), deep, burgundy-red

‘Homestead’ buckeye (A. × marylandica ‘Homestead’), orange-red

9) Birch, especially:

Yellow birch (Betula alleghaniensis), bright yellow

Sweet birch, cherry birch (B. lenta), bright yellow

Paper birch, canoe birch (B. papyrifera), yellow

10) Yellowwood (Cladrastis kentukea), bright yellow to gold

 

Top 10 Shrubs for Fall Color

1) Large and dwarf fothergilla (Fothergilla major and F. gardenia), yellow-orange to red, outstanding

Large fothergilla (Fothergilla major)
Large fothergilla (Fothergilla major)

2) Common and vernal witchhazels (Hamamelis virginiana and H. vernalis), bright yellow to golden-yellow

Vernal witchhazel (Hamamelis vernalis)
Vernal witchhazel (Hamamelis vernalis)

3) Virginia sweetspire (Itea virginica), dark reddish-purple

4) Black and red chokeberries (Aronia melanocarpa and A. arbutifolia), red-orange, wine-red to purple

Black chokeberry (Aronia melanocarpa)
Black chokeberry (Aronia melanocarpa)

5) Sumacs, especially:

Shining sumac, winged sumac (Rhus copallinum), bright red to scarlet

Prairie Flame® shining sumac (Rhus copallinum 'Morton')
Prairie Flame® shining sumac (Rhus copallinum ‘Morton’)

Staghorn sumac (R. typhina), orange to scarlet

Smooth sumac (R. glabra), orange to scarlet-purple

Fragrant sumac (R. aromatica), orange, red to purple

6) Oakleaf hydrangea (Hydrangea quercifolia), reddish-orange to wine

7) ‘Tor’ birchleaf spirea (Spiraea betulifolia ‘Tor’), orange to reddish-purple

8) Viburnums, especially:

Withe-rod viburnum (Viburnum cassinoides), orange-red, crimson to purple

Blackhaw viburnum (V. prunifolium), reddish-purple

Arrowwood viburnum (V. dentatum), depends on cultivar, yellow, red to purple

American cranberrybush viburnum (V. opulus var. americanum, formerly V. trilobum), yellow to reddish-purple

Doublefile viburnum (V. plicatum f. tomentosum), wine-red

‘Wavecrest’ Siebold viburnum (V. sieboldii ‘Wavecrest’), red to burgundy

9) Cranberry cotoneaster (Cotoneaster apiculatus), deep reddish-purple

Cranberry cotoneaster (Cotoneaster apiculatus)
Cranberry cotoneaster (Cotoneaster apiculatus)

10) Virginia rose (Rosa virginiana), deep reddish-purple

 

 

Laura Jull, Ph.D.

a.k.a.: The “Lorax”

Fall is for Planting…Ornamental Grasses! But so is Spring…

I’ve written previously of my adoration for ornamental grasses.  A few of you folks in the mid-Atlantic might have heard my “Grasses for the Masses!”  presentation complete with lots of arm-waving. As with most of my talks, there’s usually some sort of interpretive dance involved.

Most of our warm-season ornamental grasses are in full gloriousness at the moment.  Because it’s autumn! ‘Tis the season to purchase, plant, and enjoy ornamental grasses!

Pennisetum 'Karley Rose' - available at a garden center near you!
Pennisetum ‘Karley Rose’ – available at a garden center near you!

Well, not really.  If you’d have purchased and planted them in April or May, you’d only have to do the “enjoy” part now.  And your local grower/garden center would LOVE you for it. But most gardeners overlook containers full of  6″ tall Fescue – which is what a LOT of our best grasses resemble in the spring.  It’s always been challenging to sell “green” in the spring – consumers want to see and buy plants in flower – so nurseries and greenhouses that supply garden centers do their darnedest to provide said blossoms.

Gorgeous grasses at Babikow Greenhouses near Baltimore, MD.
Gorgeous grasses at Babikow Greenhouses near Baltimore, MD.

So we pass over pots full of green grassy things in favor of enticing blooms. Nurseries have picked up on this – many include grasses in their summer/early fall production schedule, making full, fluffy pots for the autumn gardener.  This works o.k. for shorter, compact things like fountain grass, little bluestem, etc.   But by September, majestic switchgrass, big bluestem, and the like rarely look that fabulous in a one or two gallon pot – the proportions aren’t right; a bit of wind and rain and the situation is ripe for floppage (closely related to splayage). So you’ll probably pass them over. Again.  Or maybe…take a second look? Just cut them back and plant away – you’ll enjoy them NEXT fall.

Where double flowers come from (sometimes)

Doubling of flowers — the development of extra petals — is a common mutation, and often beloved by gardeners. Sometimes double forms of flowers become so popular that gardeners hardly recognize the single flowered, wild-type. Wild roses, for example, have just 5 (or, in once case, 4) petals and look totally different than the extra petal flaunting varieties familiar from gardens.

Rose rubrifolia, like other roses before human breeders got their hands on them, has only 5 petals
Rose glauca, like other roses before human breeders got their hands on them, has only 5 petals

Doubling usually happens when gene expression gets mixed up and bits of cells that were destined to develop into anthers develop into extra petals instead. Sometimes a single mutation makes a dramatic change all in a go, but more often, the path to a double flowered cultivar starts with something like this:

Iris x norrisii with three ugly little petaloids full of potential
Iris x norrisii with three ugly little petaloids full of potential

Here we have a flower of Iris xnorrisii (formerly known as x Pardancanda norrisii) with the usual six petals, and three “petaloids” — anthers that are stuck in an ugly transition between anther and petal. This is a seedling in my garden this year, and I’m going to grow out lots of seeds from it — hopefully some of them will get past the petaloid stage to full on extra petals and hey presto, a double flowered variety will be born!

Joseph Tychonievich

Robbers in the garden

Salvia azurea (maybe my favorite salvia in the world — sky blue flowers in late summer/fall, hardy to zone 5) is blooming in the garden, and the bees are all over the flowers. But while some are poking their heads into the flowers to drink nectar and transferring pollen as they do so, others are up to something more sinister.

This carpenter bee looks like it is pollinating. It isn't.
This carpenter bee looks like it is pollinating. It isn’t.

The evidence of what they are up to is clear if you look closely at the side of the flowers after they leave.

The little hole at the base of the flower is clear sign of an illegal break in.
The little hole at the base of the flower is clear sign of an illegal break in.

See the little hole in the base of the flower? That is where the carpenter bee bit a hole in the flower to get access to the nectar instead of going in the front of the flower as one would expect.

This phenomenon is called nectar robbing because it is an evolutionary betrayal of sorts. Flowers have evolved nectar to lure bees and other pollinators into the flower, so the bees will pollinate while getting their sugar fix. When the bees nectar rob, they’re getting the payment without doing the actual pollinating.

So why bite a hole in the side of the flower instead of just going in the front? Well, many flowers have evolved flower forms that make the nectar hard to reach by anything but their preferred pollinator, the species that most effectively moves pollen from plant to plant. In the case of this salvia, the nectar is down at the base of the flower, and only accessible to bees with long tongues, like whatever species normally pollinates it in its native range in the US plains. In other words, it is out of reach of the carpenter bees to save it for another bee, probably a bumble bee. Which works great to avoid wasting nectar on sub-optimal pollinators… unless, of course, those bees become robbers.

So next time you see bees on your flowers, take a look… they might just be robbers, not pollinators.

Perennial Funday: Eriogonum allenii ‘Little Rascal’

I’m going to keep posting about perennials that deserve more attention until somebody makes me stop. The fact that my subject is, once again, yellow… is merely coincidental

Definitely was a crowd favorite during the Perennial Plant Association annual Symposium’s grower tour (mentioned in my previous post).  These photos were taken at Emory Knoll Farms north of Baltimore; I believe that they were trialing and/or including it in their plant selection for green roof use.

Eriogonom allenii 'Little Rascal' at Emory Knoll Farms
Eriogonom allenii ‘Little Rascal’ at Emory Knoll Farms

Thanks to Mary Vaananen, Jelitto’s North American operations manager (and goddess of perennial plant knowledge), who just happened to be standing next to it, full of 411, when I squealed “WHAT the (blankety blank) is THAT?!” My compadre Paul Westervelt added more info, as he’s also a plant geek deluxe (and manager of the annuals and perennials section of Saunder Brothers Nursery). D’oh. Plus you rock gardening fanatics probably know this cutie as well (I may have first seen this in one of Joseph T.’s talks, now that I think about it).

Eriogonum allenii, shale barren buckwheat, is native to counties that comprise the Virginia Highlands plus those on the West Virginia side of the line in the same region. Within these counties, the scattered populations reside in the botanical wonderlands called the shale barrens.

This floriferous selection ‘Little Rascal’ is indeed from Jelitto, so you too can obtain seeds of this rarity (along with detailed germination/growing instructions). Jelitto lists hardiness to USDA zone 5. As with most species from the barrens, it requires plenty of sun and excellent drainage.

Flowers you can hear!
Flowers you can hear!

Stocky and slightly shrubby in habit, the coarse grey-green green foliage was, when I saw it at the end of July, completely smothered in deep gold flowers. Simply gorgeous.  It was abuzz with bees of all sorts, including insanely happy honey bees that could barely attain lift-off.  I have a plot of regular-old-buckwheat (same family, Polygonaceae), but our spoiled-rotten bees always seem underwhelmed.  Wait till they get a load of this!

 

Cool Plants for Late Summer

I thought today’s post would feature two awesome plants that are relatively new or unheard of in the industry. Both of these plants have performed well in my own garden and survived our two hardest winters recorded since the 1970’s. Many plants suffered severe winterburn or even death due to extremely low temperatures, but not these two plants. They may be harder to find in the nursery/garden center, but are well worth it and have huge ornamental impact all growing season.

Variegated fiveleaf aralia (Eleutherococcus sieboldianus 'Variegatus')
Variegated fiveleaf aralia (Eleutherococcus sieboldianus ‘Variegatus’)

The first is variegated fiveleaf aralia, Eleutherococcus sieboldianus ‘Variegatus’ (formerly Acanthopanax sieboldianus ‘Variegatus’). I know, a really horrible, long scientific name for such a great plant. Now before I go on about this particular cultivar, I need to let everyone know that this is the cultivar you want, NOT the species that has all green leaves. The straight species is weedy, grows too large for most landscapes and is not colorful. The variegated cultivar is a real showstopper! It is low maintenance, grows slowly and rarely needs pruning. This medium-sized shrub grows about 5-6’ tall and wide in the northern U.S. growing larger in the south. The natural form is upright, rounded with long, arching branches. Suckering at the base of the shrub is slow, hence the plant does not become a nuisance in the garden. Variegated fiveleaf aralia is adaptable to most soils and pH, tolerates sandy and poor, dry, clay-based soils, will stay variegated in shade and will not scorch in full sun. It is quite drought tolerant with no pest problems. Deer and rabbits seem to leave it alone.

Variegated fiveleaf aralia (Eleutherococcus sieboldianus 'Variegatus')
Variegated fiveleaf aralia (Eleutherococcus sieboldianus ‘Variegatus’)

The foliage is quite clean with 5-7, bright, cream to yellow variegated leaflets with an emerald green center. There is no fall color to talk about, however, the brightly colored leaves mix well with other yellow, white or purple flowering/foliaged plants. The stems do have 1-2 curved prickles on them at a node, but they are short. Unlike its straight species, ‘Variegatus’ rarely flowers or fruits so the plant does not become invasive.

This plant is native to Japan and was highly promoted as an outstanding urban tolerant plant by my former graduate advisor, the late Dr. J.C. Raulston of North Carolina State University. He tested and evaluated thousands of landscape plants for adaptability to the southeastern U.S. and a few of those plants are actually hardy up in zone 4b.

Another great plant that I am more and more impressed with each day is a relatively new release from Iseli Nursery, Boring, Oregon. It is NORTH WIND® maple (Acer ‘IsINW’). This smaller, 15-20’ tall, ornamental maple is part of Iseli’s Jack Frost® series of hardy, ornamental maples. Through testing across the country, this maple has proven hardy to zone 4a without any dieback, unlike Japanese maple (Acer palmatum). One of the parents of this great hybrid is the Korean maple (Acer pseudosieboldianum), which is also zone 4 hardy.

NORTH WIND® maple (Acer 'IsINW')
NORTH WIND® maple (Acer ‘IsINW’)

The beauty of NORTH WIND® maple is that it combines the cold hardiness of Korean maple with the outstanding leaf qualities and deeper leaf lobes of the Japanese maple, one of the suspected parents, but with one exception. NORTH WIND® maple new leaves are bright orange! The color of these leaves lasts longer in the growing season in cooler climates. I have a young tree in my yard and the leaves are still orange, even this late into August. The older leaves gradually fade to green in midsummer. The orange-red fall color is superb and makes a real eyestopper in the autumn landscape. For best color, plant the tree in full sun to partial shade.

Closeup of leaves of NORTH WIND® maple (Acer 'IsINW')
Closeup of leaves of NORTH WIND® maple (Acer ‘IsINW’)

NORTH WIND® maple is pH adaptable and grows best in a moist, well-drained soil. I do not know yet how heat or drought tolerant this species is, but if anyone is growing this plant in southern climates, please let me know how it is doing.

Laura Jull, Ph.D. aka The Lorax

 

Perennial Funday: Rudbeckia grandiflora ‘Sundance’

Just back from the always-inspirational Perennial Plant Association Symposium, this year held in Baltimore.   The theme celebrated the massive influence of German plantsmen and designers on both the mid-Atlantic and the perennial business as a whole. Whether a grower, garden center owner, or landscape designer, the names historically associated with Mid-Atlantic horticulture – Kurt Bluemel, Oehme, van Sweden & Associates, etc. – resonated with all attendees.

The history of the “perennials movement” was recounted – where the Germans (and more than a few Dutch) admired, utilized, and selected cultivars of our fabulous summer and fall-blooming native perennials – long before we North Americans ceased relegating them to ditch weeds.   And then they taught us how to use them in “New American Garden” style – sweeping herbaceous plantings (fewer species but larger quantities of each), mixed with ornamental grasses and non-native but pollinator-friendly beauties such as Salvia nemorosa and Perovskia atriplicifolia.

'Sundance' massed with Rudbeckia triloba 'Prairie Glow' in the Bluemel garden.
Rudbeckia grandiflora ‘Sundance’ massed with Rudbeckia triloba ‘Prairie Glow’ in the Bluemel garden.

But this was my first encounter with Rudbeckia grandiflora ‘Sundance’. This seed strain was introduced by Jelitto® Staudensamen seven or eight years ago. It has a pretty broad native range… Midwest to South-Central United States. USDA cold hardiness zone ratings listed as 5-8 and 4-9 from various sources. Always full sun. Didn’t see a speck of powdery mildew.

The flower habit is a bit like Ratibida pinnata – the slightly drooping petals give the sensation of movement (even with zero breeze, 90% humidity, and 96° F). The clear yellow color works with just about anything. Around 4’ tall, the sturdy stems showed little sign of flopping. I’m sure the cones will persist, adding texture as the fall progresses.

'Sundance' in action at Emory Knoll Farms.
‘Sundance’ in action at Emory Knoll Farms.

‘Sundance’ will never impress in a nursery container in May. It’s one of those you-must-see-it-in-the-garden plants. OR or you can take my word for it. And that word is “Yowza!” (Followed by “gimme gimme gimme.”)