Sunday, May 30, 2010

Halesia - Silverbell

A genus ( tribe ) of 5 deciduous shrubs and trees native to woodlands of humid summer regions of eastern North America and China. They look elegant in all seasons and have very few problems. These very useful trees are deep rooted enough that they do not obstruct the cultivation of flowers beneath.
The leaves on all are medium green and elliptic, turning to either yellow or remaining green before dropping in the fall. The blooming season is typically about 2 weeks.
The green unripened fruit are edible and can be eaten fresh as a snack.
Silverbells prefer sun to partial shade and a moist, fertile, acidic to neutral, well drained sites with shelter from strong winds. They enjoy mulch on their roots and prefer climates with cool to cold winters and hot summers. Most are hardy far north of their natural ranges. Other than training as a single stem tree, feathering, thining if needed and limbing up when young; pruning is generally not needed.
Silverbells are best trained to a single stem since multistemmed trees can be prone to splitting. Silverbells are rarely bothered by pests or disease.
The Silverbells are easily reproduced from seed, however in the wild the seeds are not an efficient way of reproduction. The seeds are heavy enough that it would take a hurricane to keep the seeds afloat so once a forest is destroyed; this tree would basically have to be planted or it will not reappear in regrowth of that same habitat. That being said; most seedlings are found in close proximity to parent trees. Seeds do germinate best if soaked for 24 hours before sowing. Softwood cuttings in summer are also used to propagate.
The Silverbells are low maintenance, never really being bothered by pests or disease.
It is best planted small and containerized for quick establishment. Ball and Burlap trees should not be used and it should not be transplanted in the fall.

* photo taken on Apr 17 2016 @ U.S. National Arboretum, DC

* photo taken on Apr 24 2016 @ U.S. National Arboretum, DC


Halesia carolina ( Carolina Silverbell )
Native to the eastern U.S. ( from Oklahoma & Arkansas east to Ohio & Kentucky; south to Mississippi east to Florida ). It typically becomes a medium size spreading tree to 40 feet; some records include: fastest growth rate - 4 feet; 6 years - 20 feet; 20 years - 27 x 33 feet; largest recorded is 70 x 66 feet with a trunk diameter of 4 feet. Spme notable large trees grow at Perdue University in West Lafayette, Indiana & in Greenwich, CT. The Carolina Silverbell is reported to live up to 100 years. My personal opinion is that on ideal sites, they may exceed that age. This is the most common of the Silverbells.
The elliptic foliage is large, up to 10 x 5 inches and turns to yellow in autumn.
The Carolina Silverbell is early to leaf out in spring, the thinly hairy foliage is bright green above, lighter below and turns to yellow in the fall.
In mid spring abundant white bell shaped flowers in pendulous clusters smother the plant.
The flowers are later replaced with 4 winged fruits up to 2 inches in autumn.
The fruit are green before ripening to light brown.
The scaly bark is light brown with scaly ridges that interlace.
Hardy zones 3 to 8 ( protected sites north of 5...trials at Dominion Arboretum in Ottawa, Canada had varying results with one tree sustaining severe but not fatal damage during severe winters and the other with no damage )

* USDA-NRCS PLANTS Database

* photo taken by W.D. Brush @ USDA-NRCS PLANTS Database

* photo taken on August 2004 @ Tyler Arboretum in Philly

* photo taken on August 3 2010 @ University of Guelph Arboretum, Ontario

* photos taken on April 12 2012 in Columbia, MD




* photos taken on Oct 17 2013 in Olney, MD

* photo taken on Oct 21 2014 in Washington, DC

* historic archive photo

* historic archive photo


'Gold Form'
Foliage is bright golden-yellow at first during spring. It is otherwise similar to species.

* photos taken on Apr 23 2017 @ Brookside Gardens, Wheaton, MD


'Rosea'
Pink flowers. It is otherwise similar to regular Halesia carolina. You can definately be the talk of the neighborhood with this extremely rare tree.

'Silver Splash'
A vigorous tree with large foliage that is dark green and splashed cream all over.
There is another cultivar called 'James Laubach' and it is my suspicion that these 2 may be the same or extremely similar. A truly spectacular tree that should be more widely used in the landscape.

* photo taken in August 2004 @ Tyler Arboretum in Philly



'Tyler's Variegated'
Foliage has bold yellow band around the outside fading somewhat in the summer. Otherwise similar to regular Halesia carolina.

'Wedding Bells'
unusually large flowers

* photos taken on May 1 2013 in Baltimore Co., MD

Halesia diptera ( Two-Wing Silverbell )
Native to southeast U.S. from eastern Texas to South Carolina; south to northern Florida. The Two-Wing Silverbell becomes a long-lived, medium size tree to 30 feet or more. Some records include: fastest growth rate - 3.5 feet; first year - 1 foot; 10 years - 20 x 15 feet; largest on record - 78 x 40 feet with a trunk diameter of 3 feet. A very large tree is known to grow at the botanical haven - Spring Grove Cemetary in Cincinnati, OH.
The elliptic foliage is up to 5 or rarely 8 x 6 inches and is minutely tooth edged. The foliage is downy when young turning to deep green.
The flowers up to an inch wide are white and in clusters of 3 to 6.
It flowers 2 weeks after Halesia carolina.
They are followed by 2 winged fruits up to 2 inches in size.
Hardy zones 4 to 8 thriving in sun or shade. Flood tolerant and is sometimes found in swampy forests in the wild.

* photos taken on April 18 2010 @ U.S. National Arboretum, D.C.





* photos taken @ U.S. Botanical Garden, Wash., DC on Aug 25 2014

* photo taken on on Aug 23 2014 in Columbia, MD

* photos taken on Sep 19 2014 in Columbia, MD

* photo taken on Oct 1 2014 in Columbia, MD

* photos taken on Oct 15 2014 in Columbia, MD

* photos taken on May 5 2015 in Columbia, MD

* photo taken on May 6 2015 in Columbia, MD

* photos taken on Apr 17 2016 @ U.S. National Arboretum, DC

* photos taken on Apr 24 2016 @ U.S. National Arboretum, DC

* photos taken on Apr 13 2017 in Columbia, MD

* photos taken on Apr 23 2017 @ Brookside Gardens, Wheaton, MD


Halesia mcgregori ( Chinese Silverbell )
An endangered medium-sized, deciduous tree native to southeastern China. Moderate growing, to 2.5 feet per year; it can reach a maximum size of 82 feet in height with a trunk diameter of 1.5 feet. It is endangered in the wild due to destruction of forest.
The toothed, elliptical leaves, up to 5 x 2 inches in size, are mid-green above, bright green beneath.
The white flowers, up to 0.6 inches in length, are borne during late spring.
They are followed by brownish-red, ovate seeds up to 1.6 x 1.2 inches in size.
The stems are purplish-red.
Hardy zones 7 to 10 ( est ). Chinese Silverbell thrives in the Carolinas and Mid Atlantic region of the U.S. Preferring full sun to partial shade on a moist, well drained soil with a PH of 5.5 to 6.5. Tolerant of wind and drought however protection from sweeping winter winds is recommended for younger trees.

* excellent photo links
http://www.arkive.org/halesia/halesia-macgregorii/
http://davesgarden.com/guides/pf/showimage/122987/

Halesia monticola ( Mountain Silverbell )
Native to the the southeast U.S. in the Smokeys Mountains and Ozarks. This is the giant of the Silverbell family and on good sites becomes a large tree with a conical or eventually wide spreading canopy, reaching up to 80 feet in height or more. More vigorous than all other Silverbells; some records include: 20 years - 50 x 50 feet; largest on record - 140 x 66 feet with a trunk diameter of 4.5 feet.
The pointed, elliptic leaves are huge for a Halesia and reach up to 8 x 4 or rarely 11 x 5 inches in size. The foliage is bright green in spring and turns to medium green in summer then bright yellow in autumn.
The abundant white flowers appear in pendulous clusters of 2 to 5 in late spring with the new foliage.
Four winged papery fruits up to 1.5 inches follow the flowers. The fruits are bright green turning to brown.
The slender brown twigs have deep reddish-brown long buds.
On young trees that bark is smooth with green and pale gray vertical stripes. On older trees the bark furrows into flat ridges.
Hardy zones 4 to 8
It the tree is cut off at the ground in the winter, the roots will respond with a tremendous surge of new sprouts capable of reaching 10 feet of growth in the first season. Thin these to the best stem the following winter. These sprouts bloom in 3 years.

* photo taken on October 17 2010 @ U.S. National Arboretum, D.C.


* historical archive photo


'Arnold Pink'
Flowers are rosy pink later fading to light pink.
Was introduced from the Arnold Arboretum in Massachussets.

'Vestita'
Pink flowers are 3 times the average size for Halesia

Halesia parviflora
A large shrub or small tree native from eastern Oklahoma to South Carolina, south to Florida; that can reach up to 16 x 25 feet or rarely more. It is the smallest of the Silverbells though records include: 6 years - 12 feet; largest on record 30 x 25 feet with a trunk diameter of 1 foot.
The leaves are smaller than most, only up to 4 x 2 inches and the bark is dark brown. The flowers are also small, to 0.5 inches.
Hardy north to zone 6. This Silverbell is more tolerant of heat and drought than the others.

RELATED TREES

Alniphyllum

Alniphyllum fortunei
A beautiful, straight-trunked, medium-sized tree, reaching a maximum height of 66 ( averaging 30 ) feet, that is native from India to western and southern China, south to Burma, Laos and Vietnam. It is rare to endangered in its native range.
The bark is grayish-brown.
The papery, broad-elliptical leaves are up to 8 x 4.5 ( rarely over 6 x 3 ) inches in size.
The foliage is glossy at first, turning to matte bright green. The foliage turns to red during very large autumn.
The white flowers are borne on racemes, up to 8 inches in length, during late spring.
Hardy zones 6 to 9 in partial shade on moist, fertile, well drained soil. It requires a site protected from excessive wind but is tolerant of drought.

var macrophyllum
Larger, glossier foliage looks tropical in appearance.
It is also less hardy, thriving from zone 7b to 10.

Rehderodendron macrocarpum ( Rehder Sausage Tree )
A slow growing, massive, spreading, medium size tree to 50 feet that is native to mountains of Sichuan and Yunnan China and nearby parts of Vietnam where it is endangered. Some records include: largest on record - 66 x 27 feet with a trunk diameter of 15 inches.
The finely serrated, elliptic to ovate-oblong leaves are up to 8 x 2.7 inches in size. The foliage is healthy, deep green and colors well in autumn, persisting late into November. The leafstalks are bright red.
The very attractive fragrant, 5 petalled, oure white flowers up to 0.7 inches in length are produced in cymes of 4 to 8, in mid spring. The fruit is a dry, bright red, hanging, sausage-like woody drupe 3 x 1 inches, containing a single seed.
The bark is dark gray.
Hardy zone 7 to 9 in full sun to partial shade, prefers moist, acidic, well drained soil and hates drought. Prefers hot summers however will grow in the Pacific Northwest and England. The Rehder Sausage Tree is not bothered by pests or disease.
Seeds are rare without cross pollination but sometimes do occur. This tree is easy to propagated from seed. Squirrels however do like the seeds and hoard them before winter. It is also easy to root semi-ripe cuttings.

Sinojackia rehderiana
This relative of the Silverbell native to eastern China is a fast growing small tree reaching up to 30 x 30 ( rarely over 20 ) feet.
The foliage is shiny deep green, up to 4 x 3 inches and appears early in the spring and lasts late in the fall often turning yellow. The oval leaves have minutely-toothed margins.
The white flowers, up to 1 inch across, are borne in cymes of 3 to 5 during late spring.
Thrives in sun or shade and is both heat and drought tolerant. Hardy zones 5 to 8

* photo of unknown internet source


Sinojackia xylocarpa ( Jacktree )
A long lived, fast growing, spreading small tree reaching up to 17 feet in 15 years, eventually to 20 x 20 feet. Some records include: 3 years - 7 feet; 5 years - 6 x 7 feet. It is native to an isolated area near Nanjing in Jiangsu Province in eastern China where it is endangered with extinction.
The large, leathery foliage is deep glossy green, up to 7 x 3 inches in size.
The white flowers, up to 1 inch across, are borne on small cymes during mid-spring.They are followed by woody drupes, up to 0.7 x 0.5 inches.
Likely hardy zones 6 to 9 in full sun to partial shade on fertile, well drained soil, it thrives from Arkansas to the Mid Atlantic. Tolerant of heat and drought and is both pest and disease resistant. Thrives in sun or shade and is hardy zones 6 to 8.

No comments:

Post a Comment