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Wednesday, February 20, 2013

Winter Interest in the Landscape




Winter brings a dramatic change to areas with primarily deciduous forest ecosystems such as here in Maryland and similar areas in temperate zones.  December, January and February are considered the winter months here.  Usually, the dramatic colors of fall foliage displayed by many deciduous plants are all gone by December 1, as well as most flowers.  However, there are still a number of plants with various forms of winter interest that we can grow in mild temperate zones like ours. 

To me, the phrase 'Where have all the flowers gone?' used by Pete Seger in his popular folk tune of the same name, can be thought of as a metaphor for winter.  Many musical artists have made their own versions of Pete's song that he wrote to the tune of a Russian folk song "Koloda Duda."  Peter, Paul and Mary have possibly the most popular version; however, I like this version by Marlene Dietrich also.




Narcissus are coming up through the dried remains of Leadwort or Plumbago (Ceratostigma plumbaginoides) which has beautiful blue flowers in late summer and in the fall both before and sometimes as its leaves turn red in the fall.  The Plumbago in this picture is a good example of the phrase 'Where have all the flowers gone?'  However, its dried seed pods remain, adding a subtle interest with its unusual texture in the landscape when contrasted with the white backdrop of a shallow winter snow.  Plumbago and Narcissus are a good example of a successful companion planting.


Evergreen plants whether narrow-leaved evergreens or broad-leaved evergreens are some of the more obvious plants for winter interest.  They come in many different sizes with different growth rates and habits.  One of the larger evergreen plants that performs well on our campus is the Deodar Cedar (Cedrus deodara).  However, it is so large that it is best used on acreages or in public parks where that there is plenty of room for it to spread.  We are at the northern limit of the Deodar Cedar's cold hardiness range, so it would be a good idea to select a cold hardy cultivar such as 'Shalimar' if you are considering planting Deodar Cedar in the College Park, area.  This fall, we planted a related plant, Cedar of Lebanon (Cedrus libani subsp. stenocoma), on the east side of the Architecture building.  It is supposed to be a more narrow and more cold hardy form of Cedar of Lebanon which is more cold hardy than the Deodar Cedar shown here.





The above pictures are all of Deodar Cedar (Cedrus deodara).  They were taken in front of Ellicott Residence Hall.


The Dwarf Japanese Rock Garden Juniper (Juniperus procumbens 'Nana') is also a narrow-leaved evergreen like the above Atlas Cedar; however, it is very short in stature and spreads horizontally.  To me, it provides an attractive neutral texture in both the summer and in the winter, even when lightly covered with snow.  It can contrast quite nicely with the tan colors of ornamental grasses during the winter.

These Dwarf Japanese Rock Garden Junipers (Juniperus procumbens 'Nana') are covered with a light layer of snow.  There are some of these located in the Van Munching Hall Courtyard.


The number of broadleaf evergreens that can be grown generally decreases as one transitions into a continental climate in the interior of a continent or the closer that you get to the earth's polar regions.  'Alta' Columnar Southern Magnolia (Magnolia grandiflora 'Alta') is a good selection for those people that want their plants to look almost exactly the same year round.  'Alta' does get large attractive white fragrant flowers during the summer that contrast quite nicely with its dark green foliage.  The large leaves contrast quite nicely with finer textured plants. Southern Magnolias are broad-leaved evergreens.

'Alta' Columnar Southern Magnolia (Magnolia grandiflora 'Alta');  Picture taken on March 5, 2012


'Dwarf Burford' Chinese Holly (Ilex cornuta 'Dwarf Burford') is a broad-leaved evergreen that has a smaller stature than its parent.  It can easily get eight feet tall or more in a good site without pruning as it is a very long lived plant; however, it seems to tolerate pruning quite well and you may be able to maintain it around four feet in height for a number of years if you start pruning it religously when it is young.  In areas where that it is cold hardy, 'Dwarf Burford' seems to be one of the easiest to grow hollies as it appears to be tolerant of quite a number of different soil and site conditions.  'Dwarf Burford' seems to be more heat and drought tolerant once established than many other kinds of hollies.  The curator of one of the United States largest holly collections once told me that he thought that 'Dwarf Burford' was the most cold hardy of the Chinese Hollies.  'Dwarf Burford' is not near as prickly as many of the other Chinese Hollies so it is much easier to prune and friendlier to be around.  It seems to be much more resistant to problems than another popular cultivar of Chinese Holly named 'Rotunda.'  In our area, 'Rotunda' often has large gaping holes in it and twisted floppy branches giving it an unruly unkempt look, perhaps from being so slow growing and brittle compared to the much faster growing and sturdier 'Dwarf Burford.'  

Shearing the new growth, making sure not to cut off the berries, around the last week in June and a second light shearing in late fall right after the first heavy frosts often helps to reveal the red fruit or ornamental berries better on 'Dwarf Burford' Holly.  Heavy pruning for size control can be done in the early spring just before the buds break and the leaves start growing; however, you will probably lose most of your berries for that year when you do this.  


The above two pictures are of a sheared 'Dwarf Burford' Chinese Holly (Ilex cornuta 'Dwarf Burford') hedge located behind Ellicott Residence Hall.


In case you do not think that 'Dwarf Burford' is a dwarf selection, check out the size of its grandparent, the Chinese Holly (Ilex cornuta).  This plant is located on the east side of the Chemistry Building.  Picture taken on February 25, 2013.  The low evergreen shrubs underneath are Common Cherrylaurel (Prunus laurocerasus).


Nandina or Heavenly Bamboo (Nandina domestica) is usually evergreen in our area.  Not only can it have an attractive winter fruit display, it can also have an attractive reddish winter color on some cultivars.  One of the smaller cultivars of Nandina named 'Firepower' usually has a bright reddish winter color.

Please check your state or local invasive species list before planting Nandina as it is considered an invasive plant in many areas.  We defer to the recent Maryland Department of Natural Resources recommendation to avoid planting on state lands within Maryland and are no longer installing Nandina in new plantings on campus.




The above three pictures are of a Nandina or Heavenly Bamboo (Nandina domestica) hedge in a courtyard planting at the Clarice Smith Center for the Performing Arts.  It is probably the species or an unknown cultivar.  Given the variability, there is a good chance it is the species.


The two pictures above are of 'Firepower' Nandina or Heavenly Bamboo (Nandina domestica 'Firepower').  The red winter foliage of the 'Firepower' Nandina contrasts nicely with the dark green leaves of the tightly sheared 'Dwarf Burford' Holly behind them on the left.
 


Many rhododendrons and some azaleas are evergreen or semi-evergreen in habit rather than deciduous.  The leaves on some will look almost the same in the winter as in the summer.  However, on some plants, the leaves will turn reddish, purplish or bronze in the winter.  Many of the very winter hardy 'P.J.M.' hybrid rhododendrons have leaves that turn a different color during the winter.


The two above photos show the reddish foliage on 'Johanna' Azalea (Rhododendron 'Johanna') located in the H. Edward Reiley Rhododendron and Azalea Garden at the Arboretum Outreach Center.
 


The two photos above show the green winter foliage of 'Eikan' Azalea (Rhododendron 'Eikan').  'Eikan' comes from the Satsuki hybrid group of azaleas.  These pictures were taken in the H. Edward Reiley Rhododendron and Azalea Garden at the Arboretum Outreach Center.  A mass of the 'Eikan' Azaleas or similar azaleas with green winter foliage could contrast quite nicely with a mass of the 'Johanna' azaleas or similar azaleas with red winter foliage when planted next to each other.  This color contrast will last far longer than the brilliant but fleeting colors of the flowers. 
 


'Color Guard' Yucca or Adam's Needle (Yucca filamentosa 'Color Guard') is still looking good on February 25, 2013 in this photo taken north of the Chemistry Building.  'Color Guard' is doing quite well in this hot location surrounded by the reflective heat of concrete.



Japanese Star Jasmine (Trachelosperum asiaticum) turns a purplish red color in the winter similar to Purpleleaf Wintercreeper Euonymus (Euonymus fortunei var. coloratus).  This planting is located on the north side of the Student Union near the loading docks in a shaded location under trees.  We are on the northern edge of its cold hardiness range.   In areas to the south and southeast of College Park or in protected locations, it might make a good substitute for Purpleleaf Wintercreeper Euonymus as I have never seen this groundcover bloom or set fruit like the Purpleleaf Wintercreeper Euonymus which is considered invasive in many areas.  Picture taken on February 25, 2013.



One might think that deciduous plants hold little winter interest because of their nature of losing their leaves in the winter.  Losing leaves in the winter can actually be an asset to some plants as far as winter interest is concerned as there are no longer any leaves to hide the ornamental fruit or seed pods, ornamental bark or twigs or sculpture like growth habit of some plants.
River Birch (Betula nigra) and Paperbark Maple (Acer griseum) are examples of trees with attractive peeling bark in the winter time.  The River Birch cultivar 'Heritage' has far superior ornamental bark compared to seedlings.  One must remember that River Birches become large shade trees and are only small ornamental trees when first planted.  They grow far larger than people realize as they often only think of them when that they are small and at their showiest. 

The Paperbark Maple (Acer griseum) is a much smaller tree than the River Birch and more suitable for smaller yards.  The Paperbark Maple appears to like cool summers and care should be used when siting it so that it is not placed in a hot location with reflected heat. 



The above three pictures are of River Birch (Betula nigra).  They are probably the cultivar 'Heritage.'  The first picture was taken at the Arboretum Outreach Center on January 26, 2012.  The second two pictures were taken near Mowatt Circle on Campus Drive on December 20, 2009.  




The above four pictures are of a Paperbark Maple (Acer griseum) located between Ellicott Residence Hall and Stadium Drive.  The top two pictures were taken on November 15, 2012 and the bottom two pictures were taken on January 26, 2013.
 

Bur Oak (Quercus macrocarpa) is a magnificent tree with one of the most extensive ranges of any North American native tree.  While very different, both the summer appearance and the winter appearance of this tree are outstanding!  There is quite a bit of variation in this tree species over its range.  This is one of the few trees that can not only survive, but also look quite attractive when planted in the right location in the extreme climate of Western Kansas.  Old mature trees grown in full sun often develope a beautiful widespread horizontal branching habit with massive limbs.  However, this is a disadvantage for older mature trees during extreme ice storms as these picturesque horizontal branches are brittle and collect a lot of ice.  Open groves of mature Bur Oaks dot the hillsides in pastureland West of Omaha, Nebraska.  Cattle resting underneath of these Bur Oaks for protective shade in the mid-day summer heat completes one of the more beautiful and memorable images of any tree species that I have seen.

Some Bur Oaks have fairly simple leaves with wavy leaf margins, while others have extremely deeply cut lobes creating intricate leaf shapes that make great stamps for art projects involving colored paints or ink.  Some have light green back sides to the leaves and others have a much more silvery back side to the leaves.  Some are very resistant to disfiguring and in a few cases lethal insect galls while others are extremely susceptible to them.  Some are very resistant to powdery mildew while others are very susceptible to powdery mildew.  Some are very slow growing as they can grow and survive in very inhospitable environments and I have seen the central leader of a young tree grow 44 inches in one year under favorable conditions. 

The fringed cups of Bur Oak acorns can reach up to 3.5 inches in diameter on certain trees in Southeast Kansas that I suspect might be natural tetraploids.  I have seen a sterile tree before; however, I am not aware of any nurseries that are propagating sterile clones.  The large and often plentiful acorns on Bur Oaks are a wildlife bonanza; however, this plus the large potential size limit the urban use of this tough and adaptable tree.  Suspect that this may be a pollution tolerant tree as I have seen it look great where some of its roots reached into soil contaminated with gasoline and motor oil.  Years ago, a prominent mail order nursery promoted Bur Oaks as being tolerant of gas damage. 

Some Bur Oaks have prominent corky wings and thick bark on the young twigs that helps protect them from fire as young trees trying to grow in the prairie regions of our country.  Not all Bur Oaks have these prominent corky wings on their twigs.  I was thrilled to discover that a new planting on campus of three Bur Oaks to replace the former Chapel Oak has trees with prominent corky wings and a picturesque growth habit already at a relatively young age.


 
The above three photographs are of Bur Oaks (Quercus macrocarpa) recently planted on campus to replace a massive White Oak that died known as the Chapel Oak.  The middle tree in the top picture shows a growth habit often seen in the young Bur Oak trees of Southeastern Kansas.  Picture taken on February 5, 2013.






The Chinese or Lacebark Elm (Ulmus parvifolia) has an attractive winter appearance.  The branches and trunk have an interesting exfoliating bark.  These Lacebark elms are located between Taliaferro Hall and the Shoemaker Building. 





Allegheny Serviceberry (Amelanchier laevis) is a small tree that attracts attention with its multiple and sometimes somewhat twisted stems emerging from the ground.

Allegheny Serviceberry (Amelanchier laevis) located behind the Ellicott Residence Hall.





The pictures below are of a magnificent old specimen of Weeping European Beech (Fagus sylvatica 'Pendula') in Wooster, Ohio.  You will need one heck of a big yard to make room for a giant specimen such as this one.  If you have a small yard, you may want to choose a much smaller tree such as a Weeping Mulberry. 







All seven of the above pictures are of a magnificent old Weeping European Beech (Fagus sylvatica 'Pendula') on the campus of the Ohio Agricultural Research and Development Center in Wooster, Ohio.  The OARDC campus is next door to Secrest Arboretum.  The building seen through the weeping branches in the bottom picture is the Administration Building.  Pictures were taken on January 18, 2013





The Weeping Mulberry (Morus alba 'Chapparal') is a tough plant that will tolerant life even in the extreme climate of the plains states such as Kansas and Nebraska.  Judicious thinning out pruning can enhance the appearance of these small trees with a contorted and weeping branch habit.

Weeping Mulberry (Morus alba 'Chaparral') at the Secrest Arboretum in Wooster, Ohio on January 19, 2013.
Harry Lauder's Walkingstick (Corylus avellana 'Contorta') is twisted!  The summer leaves hide much of the twisted character of this speciman shrub; hower, fall leaf drop reveals a very contorted branching habit.  In honor of this twisted plant, here is a link to 'Twisted' by Santana.  This is a plant that does not thrive in harsh continental climates and is lucky to survive three to five years in Lincoln, NE.


The above three pictures are of a Harry  Lauder's Walkingstick (Corylus avellana 'Contorta') located between Dorchester Residence Hall and Campus Drive.  Picture taken on March 21, 2011.

Many trees and shrubs have ornamental fruits that both create winter interest and feed wildlife .  Many plants in the Rosaceae family such as Hawthorns and Pyracantha have ornamental fruit.

'Winter King' Green Hawthorn (Crataegus viridis 'Winter King') has persistent fruit that are still attractive in this photo taken on February 5, 2013 between the Stadium Drive Parking Garage and the Riggs Alumni Center.



'Winter Red' Winterberry Holly (Ilex verticillata) is a deciduous holly that loses its leaves in winter.  This helps display its showy red fruit at its best rather than having evergreen foliage hiding many of the fruit.  It is a female holly clone that needs a male clone that blooms at the same time such as 'Southern Gentleman' in order for their to be successful pollination and heavy fruit set.  Not all male clones bloom at the correct time to pollinate 'Winter Red' as it needs a late bloomer such as 'Southern Gentleman' to pollinate it.

I recommend buying deciduous hollies in the fall as some clones sold as 'Winter Red' are not the true 'Winter Red' clone.  These imposters often have little to no fruit display in the fall and winter, even when the correct pollinator is present.  When buying, only select plants that are heavily fruited as even the 18" suckers of the true 'Winter Red' can have fruit if that the correct male pollinator is present nearby when that they are blooming.

Demand your money back from a nursery if it has not sold you a true high quality clone of 'Winter Red.'  A wholesale nursery in Maryland that sells branches of Winterberry Hollies such as 'Winter Red' for holiday decorations will not buy liners of 'Winter Red' because of the high probability of getting a mislabeled or inferior clone.  Instead, it propagates its own 'Winter Red' so that it is sure to get the true high quality clone that fruits heavily.


The above two pictures are of 'Winter Red' Winterberry Holly (Ilex verticillata 'Winter Red').  In the lower picture notice the small sucker in the lower right corner of the picture that has fruit on it.
 

A few trees and shrubs have brightly or attractively colored twigs in the winter.  If you have ever driven through the seemingly endless and monotonous suburbs of the northwest Chicago metro area during the winter, the landscape there can seem quite dreary there in the winter.  However, occasionally the bright yellow color of a large Niobe Weeping Willow (Salix alba 'Tristis') with its spectacular weeping habit catches ones attention and uplifts ones spirits.  This bright yellow twig color is seen both on mature and young plants.

The bright yellow twig color of the Niobe Weeping Willow (Salix alba 'Tristis') is evident even in very young trees like the one pictured, long before they have matured and have developed their long pendulous branching habit that they are famous for.

Redosier or Redtwig Dogwoods (Cornus sericea) and the closely related and similar in appearance Bloodtwig Dogwoods (Cornus sanguinea) are rather nondescript shrubs when in bloom and when in leaf; however, about the time that they lose their leaves and cold weather arrives is when you start noticing their colorful winter twigs.  As early spring arrives, the twigs start losing their bright colors and return to a much more drab appearance.  Redtwig Dogwoods are often maintained as cut back shrubs to stimulate fast growing vigorous new shoots that will color up well during the winter.  Older, slower growing stems do not color up as well as new shoots from the previous summer.  If these older stems are left there, they hide the bright colors of the new shoots mixed in among them. 

'Bailey's' Redtwig Dogwood (Cornus sericea 'Baileyi') is an older cultivar; however, I think it is still one of the better large vigorous cultivars for bright red winter color.  To me, the winter appearance and performance is far superior to some of the other older cultivars such as 'Cardinal,' 'Isanti' and 'Kelseyi.'  There is a yellow twigged version of the Redtwig Dogwood;' however, it has not impressed me as being nearly as attractive of a plant as 'Bailey's.' 


 
 
The above three pictures are of 'Bailey's' Redtwig Dogwood (Cornus sericea 'Baileyi') in the Peace Garden.

There are some newer cultivars of the closely related and almost identical Bloodtwig Dogwood (Cornus sanguinea) that are giving 'Bailey's good competition.  'Winter Flame' certainly caught my attention when I first saw it at the Delaware Center for Horticulture ten years ago.  It was the first Dogwood with multiple bright colors on its stems that I was aware of.  The colors exhibited on the twigs of 'Winter Flame' are very similar to the colors in the flame from a wood fire.  The lower part of the twigs are yellowish and as you near the outer tip, the color changes to yellow-orange, then orange and finally reddish orange.  'Winter Flame,' 'Midwinter Fire' and 'Winter Beauty' are nearly identical looking and/or possibly are the same plant.  I get the names confused and sometimes say 'Midwinter Flame' which appears to be a nonexistent plant.  There are a couple of other Cornus species that can get red twigs; however, persistent pest problems such as canker make them a poor choice for the landscape.
  
In January 2013, a planting of four 'Winter Flame' behind the police station at Secrest Arboretum in Wooster, Ohio stood out like a flare, clearly visible from the rose garden about 1/4 mile away.  Secrest Arboretum is a must see for a hardy plant geek like me!  Would love to be walking among the trees in the large crabapple evaluation plot when it is in full bloom.  I have never seen so many different crabapples in one place.  Secrest's large rose garden is very well laid out and contains one of the largest collections of species and hardy shrub roses that I remember seeing.  Some of these roses have beautiful red winter bark or even attractive exfoliating bark.   Others have broad wing like thorns lining the twigs and a few still had moderately attractive rose hips.  









The above seven pictures are of 'Winter Flame' Bloodtwig Dogwood (Cornus sanguinea 'Winter Flame').  These photographs were taken on January 18, 2013 behind the police station at Secrest Arboretum in Wooster, Ohio.


The above three photographs are of 'Winter Flame' Dogwood (Cornus sanguinea 'Winter Flame') taken at the University of Delaware Botanic Gardens on July 27, 2012.  UDBG cuts back this plant to the ground every other year which helps to keep the color of the twigs more brilliant in the winter.  Given the size of this plant, it appears this photo was taken in the second summer after cutting back.

Apparently, I am not the only one to get confused as to the identity of dogwoods with 'red twigs.'  This last spring, we specified Cornus sanguinea 'Midwinter Fire' on a landscape bid.  The plants came with three different labels: Cornus sanguinea 'Midwinter Fire,' Cornus sanguinea 'Farrow' (Arctic Fire) and Cornus sanguinea 'Cato' (Arctic Sun).  The plants appeared healthy and attractive and were very uniform in appearance, so even though I did not know what they were, I decided to go ahead and accept them.  After doing a phone call trace back to the wholesaler, we found out that the plants had been purchased as Cornus sanguinea Farrow' (Arctic Fire) by the wholesaler.  However, the plants that were planted did not have twigs that were a uniform bright red as described for 'Arctic Fire.'  We decided that the plants most closely fit the description of Cornus sanguinea 'Cato' (Arctic Sun). 




The above four photos are of Arctic Sun Bloodtwig Dogwood (Cornus sanguinea 'Cato') taken on August 1, 2012 near the north wing of Van Munching Hall.




 
The above four photos are of Arctic Sun Bloodtwig Dogwood (Cornus sanguinea 'Cato') taken on October 24, 2012 near the north wing of Van Munching Hall.


 
The above three pictures are of Artic Sun Bloodtwig Dogwood (Cornus sanguinea 'Cato' [Arctic Sun]).  These pictures were taken on February 5 & 6, 2013 northwest of the north wing of Van Munching Hall. 





Oakleaf Hydrangea (Hydrangea quercifolia) can have attractive exfoliating bark on its stems and branches.


There are many cultivars and hybrids of witchhazel available that provide bloom from late fall through late winter on warm days.  Some of these are wonderfully fragrant.  Unfortunately, many of those with the best fragrances have smaller and less showy flowers.  Neither of the two witchhazel cultivars with large showy flowers  shown in the pictures below are fragrant.



 
'Pallida' Witchhazel (Hamamelis mollis 'Pallida) puts on a late winter floral display in the Peace and Friendship Garden.  The above three pictures of 'Pallida' were taken on February 5, 2013.






The above four pictures are of  'Ruby Glow' Witchhazel (Hamamelis x intermedia 'Ruby Glow').  This plant is located on the East side of Marie Mount Hall.  These pictures were taken on February 5, 2013.

The above picture is of Vernal Witchhazel (Hamamelis vernalis).  The flowers are about 1/4 the size of the two hybrids shown above this and are barely noticeable from just a few feet away as they read as a neutral tan color from a distance.  However, the fragrance of these Vernal Witchhazels is exquisite.  There are a number of these Vernal Witchhazel planted in the Van Munching Hall courtyard.  This picture was taken on February 25, 2013.




Some plants have dried flowers or seed pods that can provide winter interest.  Two hydrangea species are notable for retaining their dried sepals and seed pods.  The Smooth Hydrangea (Hydrangea arborescens) and the Panicle Hydrangea (Hydrangea paniculata) do this.  Both of these lose their leaves; however, the stems are sturdy enough to support the spent and dried inflorescence, even when cold wet snow piles high on top.  'Haas' Halo' Smooth Hydrangea is supposed to be a more uniform, vigorous and showy improvement on the 'White Dome' Smooth Hydrangea that we have in our collection.  Hope to be able to plant 'Haas' Halo' soon to see if it meets up to expectations.


 
The above two pictures are of 'White Dome' Smooth Hydrangea (Hydrangea arborescens 'White Dome').  These plants are located in front of Tawes Hall on Tawes Plaza.  Both of these pictures were taken on February 25, 2013.

'Tardiva' Hydrangea (Hydrangea paniculata 'Tardiva') located on the West side of the Architecture Building.  Picture taken on February 25, 2013.

Roses are one of the oldest ornamental plants to be cultivated by man.  There is a lot of variation in the genus Rosa that roses are placed in.  Most people think of hybrid tea roses when the name rose comes up.  Hybrid tea roses produce the large, fully double, longstemmed flowers that are used in florist arrangements.  By concentrating on selecting traits for producing the most beautiful flowers with continual bloom, some other very important traits were left out when breeding tea roses.  Some of the traits that got discarded in the trash bin were a nice habit, handsome disease resistant foliage, cold hardiness etc.  Keeping a collection of hybrid tea roses healthy and attractive is a very high maintence task usually involving pesticides.

Many people abandoned the use of roses in the garden and landscape when they realized there were better looking plants available than hybrid tea roses that took a fraction of the work.  Bill Radler changed things all around again when he bred the Knock Out series of roses and other hardy shrub roses.  Knock Out and other roses developed by Bill Radler are great landscape roses that we use a lot of on campus in high visibility areas because of their near continual bloom, good disease resistance and excellent cold hardiness.  The fact that Knock Out rose is a great rose is no big secret as it is the most planted rose in the United States for good reason.

There are a few less well known roses than recent hardy shrub rose introductions that are much harder to get ahold of that have good seasonal beauty and better winter interest than the Knock Out roses.  These are good plants to use in less important areas as some may not be very disease resistant and only have a one time short blooming period.  Smaller plants including perennials can be placed in front of the larger roses to become the focus of attention after the roses have lost their blooms.  Hardy Hibiscus and Joe-Pye-Weed are taller perennials that are slow to develop in the spring when the roses are blooming, so they do not hide the rose when they are in their prime.  Later in the summer when the roses are not looking so good, these plants can help screen the roses if planted in front of them.  They both can be chopped back to the ground after frost to reveal the winter interest of the below roses.

The below pictures of roses were taken on January 18, 2013 at the Garden of Roses of Legend and Romance at the Secrest Arboretum & Gardens in Wooster, Ohio.  I will show pictures of only my three top roses.  Other roses that caught my attention for winter interest that are not shown are: Rosa des Peintres (Centifolia Rose), Sweet Briar Rose (Rosa eglanteria), Crimson Shower Rambler, Therese Bugnet Rose and Burr Rose (Rosa Roxburghii).  Burr rose has a wonderful peeling or exfoliating bark that is generally light gray on older stems. 








The above four pictures are of Pasture or Carolina Rose (Rosa carolina). These pictures were taken at the Secrest Arboretum on January 18, 2013.  Summer pictures of the Pasture Rose.











The above seven pictures are of the Chinese Winged Thorn Rose (Rosa sericea subsp. Omeiensis f. pteracantha).  The winged thorns are red in summer.  These pictures were taken on January 18, 2013 at the Secrest Arboretum.  Summer pictures of the Chinese Winged Thorn Rose.




The above seven photos are of The Semi Rose (Rosa laxa Retzius).  These pictures were taken on January 18, 2013 at the Secrest Arboretum.  The Semi Rose has both attractive fruit and attractive pinkish red to red stems and twigs.  The summer appearance of The Semi Rose.




Some grasses can proved winter interest such as Broom-sedge (Andropogon virginicus) which stands upright throughout the winter.  In our area, Broom-sedge is a native grass and its use is preferred over the larger, spectacular and often invasive non-native Maiden Grass (Miscanthesis sinensis).  If you desire a larger native grass, 'Northwind' Switch Grass (Panicum virgatum 'Northwind) stands up well to hurricane force winds much better than most other cultivars of Switch Grass.  Keep in mind that grasses that dry out completely in the winter are extremely flammable and should not be planted in areas where that they will cause damage if that they accidentally catch fire.  Cutting back the dried foliage to the ground greatly reduces the flammability; however, you lose the wonderful winter interest.





The above three pictures are of Broom-sedge (Andropogon virginicus).  The top two pictures were taken between US 1 Highway and the A.V. Williams Building on November 15, 2012.
 




Winter appearance of the species or an unknown small green leaved cultivar of Switch Grass (Panicum virgatum).  This particular planting usually falls over very early in winter; however, still looks attractive as a much lower planting as it is planted in front of some larger shrubs.  This planting is located near Mowatt Circle and Campus Drive.  The above two pictures were taken on January 11, 2013.



 

Try using plants that retain their dried foliage and contrast the color and texture differences of their dried foliage.  The dark brown foliage of the 'Wood's Blue' Aster and the light tan foliage of the Fountain Grass contrast nicely.  The dark brown foliage of Mountain Mint would also contrast nicely with the Fountain Grass.

The low dark brown groundcover in the middle of this picture is the dried remains of 'Wood's Blue' New York Aster (Aster novi-belgi 'Wood's Blue').  Behind and to the right of the 'Wood's Blue' is the light tan winter appearance of Fountain Grass (Pennisetum alopecuroides).  The contrast in color and textures of the dead foliage of both of these plants provides winter interest.  Picture taken on November 30, 2012 in front of Tawes Hall.
 
Mountain Mint (Pycnanthemum) seed heads mature and age to a handsome dark grayish brown color in the winter and contrast quite nicely with lighter colored grasses.  Picture taken on January 18, 2013 at the Secrest Arboretum in Wooster, Ohio.


The light tan dried seed pods of 'Dark Knight' Blue Mist Spirea Caryopteris x clandonensis 'Dark Knight') add a graceful screen to soften the base of a clump of Pampas Grass (Cortaderia selloana) in a planting in front of Shoemaker Hall.  This planting was designed by Bobby Tjaden, UMD Landscape Architect Reviewer with the Department of Capital Projects.  This picture was taken on February 5, 2013.
  
This recent planting in front of Shoemaker Hall designed by Bobby Tjaden, UMD Landscape Architect Reviewer with the Department of Capital Projects has a lot of winter interest.  Boxwood (Buxus) are the broad-leaved evergreen shrubs planted as a hedge and lining the walk.  Behind the Boxwood hedge from left to right are 'Dark Knight' Blue Mist Spirea (Caryopteris x clandonensis 'Dark Knight,' Blackeyed Susan (Rudbeckia hirta) and Pampas Grass (Cortaderia selloana).  Pampas Grass has large showy seed heads.  This picture was taken on February 5, 2013

'Blue Fortune' Anise Hyssop or Agastache (Agastache foeniculum 'Blue Fortune') retains its seed pods which stand out quite nicely here in this picture where it was planted in front of 'Karl Foerster' Feather Reed Grass (Calamagrostis x acutiflora 'Karl Foerster').  Bobby Tjaden, UMD Landscape Architect Reviewer with the Department of Capital Projects, designed the garden where that this picture was taken in front of Shoemaker Hall.  The seed heads have a much more relaxed habit here in this picture than they do in late summer when they are blooming as they are usually stiffly erect at that time.  The picture was taken on February 5, 2013.




Italian Arum (Arum italicum 'Pictum') is a herbaceous perennial that is evergreen through the winter in mild climates.  The leaves do roll up for protection on the extremely cold winter days, but unfurl during relatively warmer days.  Interestingly, it goes dormant during the hot summer months and appears to disappear from the landscape during this period except for its seed stalks topped with bright orange red berries.

Italian Arum (Arum italicum 'Pictum') in the Benjamin Building Courtyard Garden on November 12, 2012.



Hellebores have quite a passionate fan club among a number of gardeners.  These flowers with evergreen foliage start blooming during late winter and appear to bloom into early or sometimes mid-spring as the showy sepals that they have instead of showy petals are very durable and often hold on, even as the seed pod is maturing.  Hybridizers have been successful at breeding many variations of the flowers of the Lenten Rose including double flowers.  To me, the Lenten Rose is at its best as a cut flower, brought indoors to enjoy, as its flowers hang downwards so that you cannot see the beautiful face.  They look quite lovely when placed face up in a shallow bowl of water.



The above two pictures are of an unknown Lenten Rose or Hellebore (Helleborus orientalis) hybrid.  These pictures were taken on February 26, 2013.  This plant is located at the southeast corner of The Diner located behind Ellicott Residence Hall.
 

Bearsfoot Hellebore (Helleborus foetidis) sometimes known as Stinking Hellebore.  This picture was taken on February 26, 2013 on the south side of Building 2 in the South Campus Commons.  This plant did not read its cultural description of needing some shade as it is doing fine on the south side of a multi-story residence hall without any shade.  I am certainly not recommending that you plant them in full sun.

 


Redbor Kale can look attractive through the winter in mild winters in our area.  While a number of different ornamental cabbages and kale look attractive in the fall, Redbor is one of the best for surviving mild winters in good shape.  Not sure where the red in the name comes from as looks a little more like a grayish shade of purple to me.



Redbor Kale on February 25, 2013 at the clock tower on Mayer Mall near Van Munching Hall.



Sculpture or yard ornaments can create visual interest in the winter.  One of my favorites is a large flock of the old time classic bright pink plastic flamingos in a front yard.  They show a spirit of fun and humanity that is often lacking in some neighborhoods.  A family of turtle sculptures that I saw recently at the Secrest Arboretum would appear quite at home on our campus as our mascot is a Terrapin, a type of turtle.


These turtles serve a dual purpose as sculpture and playground equipment at the Secrest Aboretum in Wooster, Ohio.  Picture taken on January 18, 2013.

This metal spider sculpture adds some jolly good fun to a large landscape bed between Mowatt Circle and the Art/Sociology building.  Picture taken on February 5, 2013.

A metal sculpture like this can break up a blank wall or tall privacy fence and add year round interest.  This was a student art project that was displayed on campus on December 14, 2011.



Lighting and light fixtures can add winter interest during this season of long nights and short days.  This lamp post being swallowed by this large evergreen holly hedge near the Rossborough Inn is the University of Maryland's version of the lamp post in 'The Chronicles of Narnia: The Lion, the Witch and the Wardrobe' where that Lucy first meets Mr. Tumnus, the faun, in a snowy winter scene. There is a large Southern Magnolia in the background. Southern Magnolias are large broad-leaved evergreen trees. 

A big thank you goes to Dr. Laura Summerhill Deeter of the ATI campus of Ohio State University for giving me a tour of the ATI campus, Secrest Arboretum and the Ohio Agricultural Research and Development Center as a number of the pictures that I used in this posting came from that visit!

All of the pictures used in this post were taken by the author, Sam Bahr.



Contact Information for the University of Maryland Arboretum and Botanical Garden

Mailing and Shipping address (This is the location of our partner, UMD Landscape Services, and the office of our Assistant Director, Karen Petroff):
University of Maryland
Wye Oak Building (428)
4201 Landscape Ln.
College Park, MD 20742-7215
phone: 301-405-3320
fax: 301-314-9943
hours: 6 am to 2:30 pm, M-F

Horticulturist's Offices and Meeting Room (No mail delivery or shipping to this location):
University of Maryland
Arboretum Outreach Center (156)
3931 Stadium Dr.
College Park, MD 20742
phone: 301-405-3320
fax: 301-314-9943
hours: 7 am to 3:30 pm, M-F, by appointment or prescheduled times only, as sometimes everyone is out on campus and the building will be locked

When using the UMD Campus Map, you can click on a building name and the street address of that building and other information about that building should come up in a pop up window.

blog administrator, Sam Bahr, 301-405-7926 or 301-405-3320
e-mail: sbahr@umd.edu

updated 1/30/20

Parking

Our gardens are free and open to the public. There are some parking lots (read the signs for that parking lot carefully) that are free to park in after 4 pm and before 7 am and on weekends, except on game days and during other special events. There is public parking in four large parking garages at the rate of $3 per hour with a daily maximum of $15. On weekends in the garages, the rate is $3 per hour with a daily maximum rate of $5 per hour. There is a small amount of additional pay parking along some streets.

Navigation around campus is much easier with this interactive campus map. You can look up parking locations and building locations using this map. Use the search tab to bring up the page to search for campus building names, locations and addresses. If you click on a building name on this interactive campus map, a popup window should appear with the address and other details about the building.

updated 10/6/2015


Butterfly feeding on the nectar of Russian Sage blossoms

General Information about the UMD Arboretum and Botanical Garden

The University of Maryland, the state’s flagship campus, is located in the Baltimore-Washington corridor. The American Association of Public Gardens, by designating the university as an arboretum and botanical garden in 2008, recognized former President C.D. Mote, Jr.’s commitment to becoming a green campus. Maryland is also the first university in the state to be honored as a Tree Campus USA by the Arbor Day Foundation.

The Arboretum and Botanical Garden consists of our entire 1,250 acre College Park, Maryland campus. The Campus collection of over 8,000 trees, garden plantings and nearly 400 acres of undeveloped urban forest is a beautiful reminder of Maryland’s history and a harbinger of Maryland’s future. The university looks at the campus’ green space as a major resource for its educational, research and service missions.

Hornbake Plaza

Hornbake Plaza
Honeylocust fall foliage color

University of Maryland Arboretum Explorer or UMD ABG Explorer (Tree and Shrub Inventory)

You can look up the identity of many trees and shrubs using this interactive campus map: https://maps.umd.edu/abg/. Herbaceous plants and even some small woody plants are not a part of this inventory. It is still a work in progress and we do not consider it a complete or entirely up to date inventory.

Our plant inventory or plant collections database can also be considered a plant database, plant search, plant locator, plant finder, plant collection database, living collections management system, plant records system or plant mapping system for campus plantings.

updated 1/30/20

Image and Link to the Interactive Campus Map Showing the Campus Plant Inventory

Tawes Plaza Gardens

Tawes Plaza Gardens
Kim's Knee High Purple Coneflower, Russian Sage, White Out Rose and Dwarf Pampas Grass are featured in this planting in 2010.