GIL NELSON · 2009-11-16 · GIL NELSON 30 the American Gardener M ENTION HOLLIESto most gardeners...

5
GIL NELSON 30 the American Gardener M ENTION HOLLIES to most gardeners and they immedi- ately conjure images of shiny, spiny, dark green leaves, a conical form, and bright red fruits glistening in the De- cember sun. There is little doubt that the winter beauty of evergreen hollies strikes a chord with many plant lovers. But evergreens are not the only hollies worthy of our attention. Deciduous hol- lies, too, can make dramatic statements in our gardens and landscapes. Unlike some deciduous plants, whose charm diminish- es with their falling leaves, deciduous hol- lies come into their own in fall and winter, their branches festooned with showy fruits that, botanically speaking, are termed drupes. As with their evergreen cousins, their brightly colored jewelry hangs on well into winter, providing birds and squirrels with a nutritious food source. There are 11 species of deciduous hol- lies native to the United States and southeastern Canada. Some, such as winterberry (Ilex verticillata), have a very broad range. Others, such as Suwa- nee River holly (I. curtissii), are confined to a very localized habitat. All are dioe- cious, meaning that some plants are male and others female. To ensure opti- mal fruit production, gardeners need to plant both male and female selections. (For a brief description of the holly fam- ily and its origins, see the web special linked to the online version of this arti- cle at www.ahs.org.) WINTERBERRY The most popular and widely grown na- tive holly is winterberry (I. verticillata, USDA Hardiness Zones 3–9, AHS Heat Zones 9–1). A wetland species in nature, winterberry is found predominantly along streams and at the edges of bogs, pocosins, floodplains, and swampy woods from Canada to northernmost Florida and west to Louisiana. It is much more common in the northeast than the Deep South and is one of the hardier deciduous hollies. Nev- ertheless, it readily adapts to garden soils and at least some hardy selections perform deciduous native Hollies BY GIL NELSON Even after shedding their leaves, these hollies shine in the fall and winter garden. This is the first of a two-part series by Gil Nelson; evergreen native hollies will be featured in the November/December issue.

Transcript of GIL NELSON · 2009-11-16 · GIL NELSON 30 the American Gardener M ENTION HOLLIESto most gardeners...

Page 1: GIL NELSON · 2009-11-16 · GIL NELSON 30 the American Gardener M ENTION HOLLIESto most gardeners and they immedi-ately conjure images of shiny, spiny, dark green leaves, a conical

GIL

NE

LS

ON

30 the American Gardener

MENTION HOLLIES to mostgardeners and they immedi-ately conjure images of shiny,

spiny, dark green leaves, a conical form,and bright red fruits glistening in the De-cember sun. There is little doubt that thewinter beauty of evergreen hollies strikesa chord with many plant lovers.

But evergreens are not the only holliesworthy of our attention. Deciduous hol-lies, too, can make dramatic statements inour gardens and landscapes. Unlike somedeciduous plants, whose charm diminish-es with their falling leaves, deciduous hol-lies come into their own in fall and winter,their branches festooned with showy fruitsthat, botanically speaking, are termed

drupes. As with their evergreen cousins,their brightly colored jewelry hangs onwell into winter, providing birds andsquirrels with a nutritious food source.

There are 11 species of deciduous hol-lies native to the United States andsoutheastern Canada. Some, such aswinterberry (Ilex verticillata), have avery broad range. Others, such as Suwa-nee River holly (I. curtissii), are confinedto a very localized habitat. All are dioe-cious, meaning that some plants aremale and others female. To ensure opti-mal fruit production, gardeners need toplant both male and female selections.(For a brief description of the holly fam-ily and its origins, see the web special

linked to the online version of this arti-cle at www.ahs.org.)

WINTERBERRYThe most popular and widely grown na-tive holly is winterberry (I. verticillata,USDA Hardiness Zones 3–9, AHS HeatZones 9–1). A wetland species in nature,winterberry is found predominantly alongstreams and at the edges of bogs, pocosins,floodplains, and swampy woods fromCanada to northernmost Florida and westto Louisiana. It is much more common inthe northeast than the Deep South and isone of the hardier deciduous hollies. Nev-ertheless, it readily adapts to garden soilsand at least some hardy selections perform

deciduous nativeHollies

BY GIL NELSON

Even after shedding their leaves, these hollies

shine in the fall and winter garden.

This is the first of a two-part series by Gil Nelson; evergreen native hollies will be featured in the November/December issue.

Page 2: GIL NELSON · 2009-11-16 · GIL NELSON 30 the American Gardener M ENTION HOLLIESto most gardeners and they immedi-ately conjure images of shiny, spiny, dark green leaves, a conical

equally well in more or less dry, sunny sites.I planted the cultivar Winter Red®—aNew England favorite—in my drought-stressed, sun-drenched garden in Georgia,where it has fruited prolifically and dou-bled in size in only two years.

As its name suggests, winterberry’s mainattraction is its ascending branches bearingbright red fruits that begin to color in earlyfall, turn bright red by mid-December, andlast much of the winter. The deep greenleaves are about four inches long and twoinches wide with an attractive quilted ap-pearance and sharply toothed margins. Infall, these sometimes take on a burgundy-red cast before dropping. It grows six to 10feet tall with a similar diameter.

Although species plants of winterberrycan be difficult to find, numerous cultivarsare available. Winter Red® is one of thebest and most widely used. A large, round-ed shrub that may take nearly 30 years toreach its maximum size, Winter Red® pro-

duces abundant three-eighth-inch-diame-ter, intensely red fruits that persist well intoFebruary. ‘Southern Gentleman’ blooms atthe same time as Winter Red® and is itsbest male pollinator.

Other excellent winterberry selectionsinclude the red-fruited ‘Red Sprite’, ‘Sun-set’, and ‘Bright Horizon’—all of whichhave larger fruit than Winter Red®. ‘RedSprite’ is more compact than Winter Red®,

with a mature height and width of aboutfour feet. It also blooms slightly earlier,making the early-flowering ‘Jim Dandy’ agood pollinator. ‘Red Sprite’ is consideredbest for USDA Zone 8 and northward, butit performs well for me in my functionallyZone 9 garden. There’s also the yellow-fruited ‘Winter Gold’, which was selectedfrom a single plant of Winter Red® that —through a “sport,” or mutation—pro-duced some branches with yellow fruits.

Winterberry also has been crossedwith the Japanese species I. serrata to pro-duce several large, robust hybrids, in-cluding Ilex ‘Sparkleberry’ (Zones 5–9,9–5). At Callaway Gardens near PineMountain, Georgia—which has one ofthe best holly collections in the coun-try—it is used to stunning effect. “We’vehad great success with ‘Sparkleberry’,”says Hank Bruno, director of horticultureat Callaway, “which fruits heavily with‘Apollo’ as the pollinator. It dominates thewinter landscape and needs some prun-ing to keep it in bounds.” A hybrid bredspecifically as a consort for ‘Sparkleberry’,

‘Apollo’ grows to 12 feet tall andwide if left unpruned.

POSSUMHAWNative to moist habitats fromthe mid-Atlantic west throughIndiana to Kansas and south toTexas and the Gulf Coast, pos-sumhaw holly (I. decidua, Zones5–9, 9–1) is another prolificallyfruiting species that is widelygrown. Like some other decidu-ous hollies, the leaves of pos-sumhaw are sometimes closelyset at the end of short, stubbyshoots, which make them appearopposite or whorled. Pos-sumhaw produces flowers andfruits as a suckering shrub, but itwill develop into a small tree ifleft to its own devices. In the

wild, mature plants may reach 30 feet tallwith an attractive leaning or arching form.It grows best in moist, organic-rich soil infull sun but will tolerate part shade.

‘Warren’s Red’, an abundantly fruit-ing female selection with an uprighthabit, has become the favorite cultivar insouthern gardens. Its leaves are slightlywider and darker green than those of thespecies and turn yellowish before falling.T

OP

: B

ILL

JO

HN

SO

N.

BO

TT

OM

: S

US

AN

A.

RO

TH

31September / October 2009

‘Sparkleberry’ holly, opposite, livens up thewinter landscape with its brilliant red fruits.Winter Red®, above, is a popular winterberrycultivar with large red fruits that persist intolate winter. ‘Winter Gold’, right, wasdeveloped from a Winter Red® plant thatproduced yellow fruits on a few branches.

Page 3: GIL NELSON · 2009-11-16 · GIL NELSON 30 the American Gardener M ENTION HOLLIESto most gardeners and they immedi-ately conjure images of shiny, spiny, dark green leaves, a conical

LE

FT

: M

ICH

AE

L S

. T

HO

MP

SO

N.

RIG

HT

: G

IL N

EL

SO

N

32 the American Gardener

The leaves often persist into late fall andearly winter—to the delight of some gar-deners and the dismay of others. RayHead, president of the Holly Society ofAmerica, is decidedly in the latter camp.“I prefer ‘Sentry’ and ‘Pocahontas’ over‘Warren’s Red’ because they don’t suck-er as much and they tend to defoliateearlier for a good display of visible fruit,”says Head. Pollinator species for this andother I. decidua cultivars include ‘RedEscort’, as well as the evergreen Ameri-can holly (I. opaca).

As Head suggests, several other red-fruited female selections of I. decidua—in-cluding ‘Council Fire’, ‘Sentry’, ‘RedCascade’, and ‘Pocahontas’—are also wor-thy cultivars. ‘Council Fire’ and ‘Pocahon-tas’ are dainty trees that mature to about 15feet tall and usually have a single trunk,erect stature, and a rounded crown similarin form to some hawthorns (Crataegusspp.). Both of these selections are northernforms that perform best north of USDAZone 9. ‘Red Cascade’ is noted for its largefruit and ‘Sentry’ for its narrow, more orless columnar crown. ‘Sentry’ typicallyloses its leaves early in the season, retainsits fruit throughout the winter, and canrival winterberry in fruit display.

Yellow-fruited forms include ‘ByersGolden’, introduced by Byer’s Nursery of

Huntsville, Alabama, and ‘Finch’s Gold-en’, also discovered in Alabama andnamed for environmental writer and nat-uralist Bill Finch. The advantage of yel-low-fruited selections is that they tend tohang longer on the hollies, perhaps be-cause they are not as visible to birds.

BEST OF THE RESTOf the other nine native deciduous hol-lies, only six are available in the trade.For the most part, these species are con-fined to public gardens and those of avidholly enthusiasts. “We propagate severalspecies of deciduous hollies from seedand cutting, but only on a small scale, be-cause we are not aware of a profitablemarket,” says Charles Webb of Superior

Trees, a wholesale nursery near Madison,Florida, that has specialized in growingnative plants for many years. Based onmy own experience, many of these hol-lies have excellent garden potential andshould be more widely used. SuperiorTrees’ retail partner, Mail Order Natives,and Woodlanders (see “Sources,” farright), offer some of the more difficult-to-find forms.

Suwannee River holly (I. curtissii,Zones 7–10, 10–7), native only in a smallarea of northern Florida, tends to grownaturally in thin, nearly neutral soils overlimestone. Some experts believe it to be avariety of I. decidua; others feel it consti-tutes a distinct species. It is distinguishedfrom typical possumhaw by having short-

HOLLY SOCIETY OF AMERICAHolly fanciers will find lots to learn from the Holly Society of America (HSA). Found-ed in 1947, HSA serves as the official registration authority for holly cultivars and aresource for both native and non-native hollies. Among the HSA’s activities is an an-nual meeting, held in the fall to ensure plenty of fruit-laden plants can be seen on thefield trips, plant displays, and garden tours. An annual plant auction includes hard-to-find hollies donated by HSA members. The 61st annual meeting will be held October29 to November 1, 2009, at Vineyard Haven on Martha’s Vineyard, Massachusetts.The society’s website (www.hollysocam.org) includes helpful listings of arboreta thathave holly collections and retail nurseries that specialize in hollies. —G.N.

Selections of possumhaw holly can eitherbe multistemmed, such as ‘Warren’s Red’,left, or develop a single trunk, like ‘CouncilFire’, above, usually does.

Page 4: GIL NELSON · 2009-11-16 · GIL NELSON 30 the American Gardener M ENTION HOLLIESto most gardeners and they immedi-ately conjure images of shiny, spiny, dark green leaves, a conical

er, narrower leaves that typically do not ex-ceed two inches long and five-eighth-inchwide. According to Ray Head, SuwanneeRiver holly blooms later than possumhaw,which effectively reduces the likelihood ofinterspecies cross-pollination.

Swamp or sarvis holly (I. amelanchier,Zones 6–9, 10–6) is an upright shrub orvery small tree that occurs mostly instanding water along slow-movingstreams and in pocosins and wet uplanddepressions. In the wild it is now con-fined to scattered populations in thecoastal plains of the Carolinas, Georgia,and the Florida panhandle.

Swamp holly is one of the few decid-uous hollies in the coastal plains that hascolorful fall foliage. The leaves turn paleyellow as the season progresses, formingan attractive contrast to the relativelylarge three-eighth-inch fruits. The fruitcolor of swamp holly is a dull red ratherthan the typical lustrous red of mostspecies. Like many wetland plants,swamp holly adapts readily to the gardenbut will likely require a modicum ofmoisture for maximum health.

Smooth winterberry (I. laevigata,Zones 4–7, 7–4) is a mostly coastal plainsspecies growing naturally in bogs, lowwoodlands, and acidic swamps. Its foliageis similar to common winterberry, but itproduces fewer and more scattered fruitsand its leaves often fade to a beautiful paleyellow in autumn. Mountain winterberry

(I. montana, Zones 5–7, 7–5) is another po-tentially tree-sized holly that can reachnearly 40 feet tall. It grows naturally onlyin the mountains and upper Piedmont ofWest Virginia, Virginia, the Carolinas, andnorthern Georgia, where it is common,but it is more difficult to find in nurseries.

The catberry (I. mucronata, Zones3–6, 5–2), or mountain holly as it issometimes called, is the newest memberof the genus Ilex. Long classified asNemopanthus mucronatus, it and theclosely related long-stalked holly (I. col-lina) are now considered by most taxon-omists to be clearly embedded within the

true hollies. Catberry is a cold-hardy,northern species that occurs naturally inboreal bogs, swamps, and on mountainslopes from Ontario and Newfoundlandsouth to Minnesota, Ohio, Indiana,Maryland, and the mountains of WestVirginia. The dull red, velvety fruits areborne on relatively long, conspicuousstalks. Unlike other deciduous hollies,catberry fruits appear during summerrather than winter. This species is notwidely available, but should definitely besought out by New England gardeners.

A HOLLY WITH POTENTIALAs the popularity of deciduous hollies in-creases, gardeners can expect morespecies and selections to enter the mar-ket. One likely candidate is the sand orCarolina holly (I. ambigua, Zones 7–10,C

OU

RT

ES

Y O

F M

ICH

AE

L G

RO

SS

/ G

EO

RG

IAN

CO

UR

T U

NIV

ER

SIT

Y

33September / October 2009

Smooth winterberry produces large red fruits that are relished by many kinds of birds.

SourcesArborvillage Farm Nursery,Holt, MO. (816) 264-3911.www.arborvillage llc.com.

Fairweather Gardens,Greenwich, NJ. (856) 451-6261.www.fairweather gardens.com.

Forestfarm, Williams, OR. (541)846-7269. www.forestfarm.com.

Girard Nurseries, Geneva, OH. (440) 466-2881. www.girardnurseries.com.

Mail Order Natives, Lee, FL. (850) 973-6830. www.mailordernatives.com.

TNZ Nursery, Louisville, KY. (502) 836-6908. www.tnz.us.

Woodlanders, Aiken, SC. (803) 648-7522. www.woodlanders.net.

ResourcesMost of the following resources areavailable from the Holly Society ofAmerica (www.hollysocam.org).

Florida’s Best Native Landscape Plantsby Gil Nelson. University Press ofFlorida, Gainesville, Florida, 2003.

Hollies: A Gardener’s Guide, BrooklynBotanic Garden, published in coop-eration with the Holly Society ofAmerica, 1993.

Hollies for Gardeners by ChristopherBailes. Timber Press, Portland, Ore-gon, 2006.

Hollies for the Landscape in the South-east by Ken Tilt, David Williams,Willard Witte, and Mary KathrynGaylor. Alabama Cooperative Exten-sion Service, Circular ANR-837.

Hollies: The Genus Ilex by Fred C.Galle. Timber Press, Portland, Ore-gon, 1997.

Page 5: GIL NELSON · 2009-11-16 · GIL NELSON 30 the American Gardener M ENTION HOLLIESto most gardeners and they immedi-ately conjure images of shiny, spiny, dark green leaves, a conical

10–7), which now enjoys onlylimited availability but isbeing investigated by breed-ers. Growing to 20 feet tall,this very attractive shrub orsmall tree occurs naturallyfrom North Carolina to cen-tral Florida and west to east-ern Texas. Because it growspredominantly in sandy up-lands and dry forests, it has ex-cellent potential for xericgardening. The leaves usuallyhave bluntly toothed marginsbut vary widely in size, shape,and color. The shiny red fruitsare about three-eighth-inch indiameter.

The inherent variability inthis species makes it an excel-lent subject for experimenta-tion. “Our planting puts onan attractive display of brightred fruit each year and has de-veloped nicely during a several-yeardrought,” says Charles Webb of Superi-or Trees. “This holly is obviously wellsuited for planting on dry sites undershade of pines.”

The knock against I. ambigua is that itdoes not hold its fruit long enough intowinter to be successful. It begins coloringearlier than some other species, however,and the fruits are very juicy, making theman excellent food source for birds.

HOLLIES IN THE LANDSCAPEWith the exceptions described above,most of the American deciduous hollieswill thrive in a moist but free-drainingsite that has moderately fertile, slightlyacidic, organic rich soil. All will grow bestin full sun or part shade.

They are well suited to gardens in muchof the eastern United States and southeast-ern Canada. West of the Rockies, winter-berry and possumhaw cultivars andhybrids such as ‘Sparkleberry’ are alsoadaptable to gardens from the PacificNorthwest down into the coastal ranges ofnorthern and central California (SunsetZones A2, A3, 1–7).

For optimum pollination, the rule ofthumb is to have at least one male plantfor every 10 females. In Native Trees,Shrubs & Vines (Houghton Mifflin,2002), author William Cullina recom-mends planting males within 50 feet offemales for best results. To ensure that

you are selecting an appropriate malepollinator—and one whose bloom peri-od will overlap that of the female selec-tions you are planting—Cullina suggestschecking with the nursery. Fred Galle’sholly book, listed on page 33, includes ahelpful chart of bloom times for decidu-ous holly selections.

In general, deciduous hollies are mostattractive when they are planted in mass-es to enhance the effect of their fall fo-liage and winter fruits. They are oftenused as screens or hedges, or plantedalong the edge of a woodland to providefood and cover for wildlife. Underplantwith spring-blooming bulbs and shade-loving perennials.

To get maximum pleasure from theirfall and winter display, plant deciduoushollies against a backdrop of evergreens ina site where they are visible from a windowor patio. That way, you can enjoy the beau-ty of the fruits and the show of birds thatwill come to feed on them. �

Gil Nelson is an author, photographer, andbotanist based in Georgia. His next book,The Best Native Plants for Southern Gar-dens, is scheduled for release by UniversityPress of Florida in 2010. T

OP

: S

US

AN

A,

RO

TH

. B

OT

TO

M:

GIL

NE

LS

ON

34 the American Gardener

Although not yet widely available in thetrade, sand or Carolina holly has shownpotential because of its drought tolerance,attractive foliage, and early fruit display.

The fruits of ‘Scarlett O’Hara’ winterberry steal the show in this fall border that includes Joe Pyeweed (Eupatorium sp.), silver willow (Salix alba var. sericea), and elephant ear (Alocasia sp.).