Thursday, July 29, 2010

Pampas Grass


An excellent architectural focal point plant or screen for full sun on deep, well drained soil with the added benefit of being deer resistant.

Cortaderia araucana
Similar to Cortaderia sellowana but is hardier, likely tolerating much lower than 0 F.

Cortaderia richardii ( New Zealand Pampas Grass )
Rarely grown in North America; this New Zealand native forms HUGE clumps with arching stems reaching up to 20 x 10 feet! It is found in swamps and along riverbanks in its native range.
The white flowers plumes are borne late summer into early fall.
Hardy north to zone 7. It is native to swampy places and lowlands and prefers full sun on moist, light soil.

Cortaderia sellowana ( Argentine Pampas Grass )
Native to Argentina and commonly cultivated in the southern and Mid Atlantic U.S.
The Argentine Pampas Grass is among the most regal and stately of all ornamental grasses reaching up to 12 ( record is 20 ) x 13 feet with huge silvery-white plumes reaching up to 40 inches in length. The plumes look great against a dark background.
The arching, saw-toothed leaves, up to 9 feet in length, are blue-green.
The foliage is evergreen in mild climates but turns herbaceous in colder winter climates.
Hardy zone 7 to 10. It can survive zone 7 winters with the clumps tied up and the root zone mulches well but is not hardy farther north. Do not cut back until early spring. For zones 5 and 6 check out some of the cultivars below. Not only is it drought tolerant, but the Argentine Pampas Grass has invasive potential in dry summer Medeiterranean Regions of California, Europe and New Zealand.
Deer and rabbit resistant. Salt tolerant.

* photo taken by John D. Guthrie @ USDA-NRCS PLANTS Database

* historical archive photo

'Andes Silver'
Compact habit to 5 x 5 feet with prolific, large creamy white flowers plumes reaching a height of 7 feet. Hardier than regular Pampas Grass, thriving from zones 5 to 10

* photos taken on July 28 2010 in Columbia, MD

* photo taken on Aug 18 2011 in Columbia, MD
* photos taken on July 27 2012 in Columbia, MD

* photo taken on Aug 1 2016 in Columbia, MD

'Gold Band'
Reaches a maximum size of 8 x 8 feet, with foliage that is striped golden-yellow.

'Pumila' ( Dwarf Pampas Grass )
Almost "dwarf", with foliage reaching up to 5 x 5 feet and profuse, creamy white flower plumes reaching up to 7 feet. It has been reported to be hardier than the species to zone 6, even surviving north into zone 5 on sheltered sites with a pine mulch.

'Rosea' ( Pink Pampas Grass )
Tall with stately foliage reaching up to 8 x 13 with stunning rosy-pink plumes reaching a maximum height of 12 feet in late summer and fall. Very fast growing, can reach 8 feet in a single season from a gallon size plant.
Evergreen north to zone 7; surviving into zones 5 and 6 as a deciduous perennial if on a protected site and under a light mulch ( pine needles work, leaves or mulch might smother the crown ).

* historic archive photo

'Sunningdale Silver'
Gigantic, reaching a maximum size of 20 x 13 ( usually about half that ) feet, with strong stems bearing very abundant flower plumes.

Grown for its huge ivory white plumes reaching up to 7 feet in height plus its extra winter hardiness ( fully hardy north into zone 6 ). It was originally discovered in the Andes foothills in Argentina in a village called Usballata.

Tuesday, July 27, 2010

Christ's Thorn


Paliurus hemsleyanus
Native to mountain forests in central and southern China; it is similar to the more well known P. spina-christi but much larger in size and foliage. It is a small to medium-size tree with the largest on record being 65 feet in height with a trunk diameter of 2.5 feet.
The obovate leaves at up to 5 x 3.5 ( rarely over 4 ) inches in size.
Hardy north to zone 9.

Paliurus orientalis
An evergreen small tree, closely related to Paliurus spina-christi but is native to mountain forests of southern China ( southwestern Sichuan & Yunnan provinces ). It is larger growing, reaching a maximum size of 53 feet.
The broadly-elliptical leaves are also larger, up to 5.5 x 3 ( rarely over 4 x 2 ) inches in size.
The smooth bark is gray.
Hardy zone 9 ( est ).

Paliurus spina-christi
A moderate growing, large shrub to 14 feet or rarely a tree, that is native from Spain to central Asia. Some records include: 20 years - 23 x 23 feet; largest on record - 33 x 30 feet with a trunk diameter of 1 foot. Excellent for use as a barrier hedge. Old plants can be cut back to the base and will regrow. This is the plant that was supposedly used to make Jesus's 'Crown of Thorns'.
The deciduous, oval leaves are up to 1.7 x 1 inches, are mid-green, turning to yellow during autumn.
The abundant, yellow-green flowers are small and borne in small clusters during spring. They are followed by a flat, round fruits with a membranous wing.
The well armed, arching stems have pairs ( 1 straight and 1 curved ) of sharp spines.
Hardy zones 7 to 10, hardy north to Baltimore. Prefers fertile, very well drained soil and a warm sunny site. Very drought tolerant.
Pruning in winter is recommended to cut out old wood and prevent overcrowding. Hedging is best pruned in winter while dormant.
Propagation can either be from seed sown during autumn or softwood cuttings taken in summer.

* photos taken on 4th of July 2010 @ U.S. National Arboretum, D.C.

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

Wollemi Pine


The Wollemia is a genus ( tribe ) of coniferous trees consisting of a single species - Wollemia nobilis. This is one of the oldest trees on earth, it has been around for over 200 million years ( the Triassic Period ). It was presumed extinct for over 2 million years when it was discovered in 1994. This is one of the most exiting and suprising of all discoveries. It looks very much like some of the related Araucarias which are also "Green Dinosaurs".
A large, very rare, majestic coniferous tree native to deep gorges of Wollemi National Park, in the Blue Mountains, 150 miles northwest of Sydney in Australia. It reaches up to 100 feet, though on ideal sites much larger to 133 x 80 feet with a trunk diameter of 4 feet. It is moderate growing ( average 20 inches per year ) with its yearly growth lasting 2 months in the spring, some records include: 3 years - 5 feet; 7 years - 10 feet; 50 years - 66 feet; 100 years - 100 feet.
This tree responds well to fertilizer. Its estimated lifespan is 1000 years.
This tree does not have much genetic variability and no cultivars occur.
The Wollemi Pine can produce stems from the base.
The juvenile foliage is fernlike, waxy and deep green. The adult foliage is also deep green but is narrow, stiff and long.
Both male and female flowers are borne on the same tree, are small and borne at the ends of the branches.
Grows best in rich, moist, acidic ( PH 4 to 6 ), well drained soil in partial shade. It is very heat tolerant and can tolerate as high as 113 F.
Rated as hardy zones 8 to 10 tolerating as low as 10 F; it may actually be much hardier than its restricted natural range suggest, with claims of even zones 5b. More testing of this tree is needed. It is one of the worlds rarest trees, its introduction into the landscape trade is its savior from extinction.
Propagation is from seed, cuttings and tissue culture.
Almost extinct in the wild, there is an international effort to build up numbers of this tree. This tree yields Taxol, an anti-cancer drug. It is very likely to be grown as a commercial crop in the future however is also an excellent, very stunning landscape tree. One of my favorite trees for sure, really looking forward to seeing more in the future.

* photos taken on 4th of July 2010 in Washington, D.C.

* photos taken on May 5 2010 @ U.S. National Arboretum, D.C.

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

* excellent video found on Youtube



Agathis atropurpurea
A huge tree native to northern Queensland where it is endangered.
The leaves are up to 2 inches in length.
Some records include: largest on record - 200 feet
Hardy zones

Agathis australis
A fast growing, majestic tree native to New Zealand.
Some records include: 20 years - 47 x 23 feet; largest on record - 308 x 120 feet with a trunk diameter of 23 feet ( estimated, such trees no longer exist due to forest destruction ); longest lived - 4000 years ( est. ). It has been planted in Athens, Georgia and trees have exceeded 50 feet in Cork, Island.
Hardy zones 9 to 12 tolerating as low as 12 F.

* historic archive photos

Agathis brownii
Some records include: 32 years - 67 feet; largest on record -
Hardy zones

Agathis dammeri
Some records include: largest on record - 200 feet with a trunk diameter of 6.5 feet.
The leaves are up to 5 x 2 inches.
Hardy zones 10 to 12

Agathis labillarderi
A huge tree native to elevations of 600 to 6000 feet in New Guinea.
Some records include: largest on record - 200 x 40 feet with a trunk diameter of 7 feet
The leaves are up to 4 x 1 inches.
The bark is dark brown.
Hardy zones 9 to 11

Agathis macrophylla
Also called Agathis vitiensis. Some records include: largest on record - 150 x 120 feet with a trunk diameter of 10 feet.
The leaves are up to 7 x 2 inches.
Hardy zones 9 to 12

Agathis microstachys ( Atherton Kauri )
A very large tree native to northern Queensland.
Some records include: 16 years - 36 feet; largest on record - 170 x 114 feet with a trunk diameter of 9 feet; longest lived- 1014 years.
The leaves are up to 3 inches in length.
The bark is brownish-gray.
Hardy zones 9 to 11

Agathis moori
A large tree, reaching up to 100 feet, that is native to mountainous subtropical rainforest, up to 3300 feet elevation on the island of New Caledonia. It is endangered due to environmental destruction. The paired leaves, up to 8 x 0.5 ( rarely over 3 on mature trees ) in size, are glossy mid-green. Hardy zones 10

* historic archive photo

Agathis palmerstonii
Some records include: 20 years - 52 feet with a trunk diameter of 10 inches; largest on record - feet with a trunk diameter of feet
Hardy zones 9 to 11

Agathis phillipensis
Some records include: largest on record - 220 feet with a trunk diameter of 10 feet
Hardy zones 11 to 12

Agathis robusta ( Queensland Kauri )
Some records include: 3 years - 17 x 10 feet; 15 years - 75 feet with a trunk diameter of 11 inches; 100 years - 102 feet with a trunk diameter of 3.5 feet; 300 years - 200 feet with a trunk diameter of 10 feet; largest on record - 200 x 60 feet with a trunk diameter of 20 feet.
Trees have already exceeded 100 feet in Los Angeles, California & reached 40 feet in Cornwall, England.
The leaves are up to 6 x 4 inches.
Hardy zones 9 to 12 tolerating as low as 15 F

* historic archive photo

subsp. 'nesophila'
Almost identical but native to the mountains of New Guinea.

Sunday, July 25, 2010


Oxydendron arboreum

A moderate growing, dense, pyramidal, small to medium sized tree native to woodlands of the eastern U.S. ( Louisiana to southern Ohio and Pennsylvania and south ) that can reach up to 30 feet or more, sometimes much larger. Some records include: fastest recorded growth rate - 4.5 feet; 1st year - 3 feet; 20 years - 40 x 20 feet; largest on record - 120 x 120 feet with a trunk diameter of 3.5 feet; largest in North Carolina - 120 feet in Robbinsville; largest in Virginia - 95 x 70 feet in Amelia Co. The Sourwood can live to as long as 263 years.
An excellent choice for a landscape specimen or underplanted in a open woodland.
The slightly wavy, finely tooth margined, elliptic leaves are pointy tipped and up to 9 x 4 inches. The foliage is bronze green at first turning to glossy deep green in summer and turns to very attractive scarlet red and purple late in autumn.
The fragrant, small, white, urn-shaped flowers, up to 0.3 inches in length, are borne in upright, spreading racemes, up to 12 inches at the branch tips during mid to late summer.
Later in autumn, the flowers are replaced with small, woody brown capsules.
The twigs are reddish and the thick bark is gray-brown, scaly and deeply furrowed.
The woods weights up to 46.5 pounds per square foot.
Hardy zones 3 to 9 the Sourwood blooms best in full sun but grows very well in partial shade. It prefers the same site conditions as Rhododendrons, preferring moist, deep, peaty, well drained acidic soil. Drought tolerant once fully established. They like their roots cool so mulching with shredded oak leaves or pine needles is recommended plus the fact that root competition from turf can stunt growth. The Sourwood does not like transplanting and is likely to grow very slowly until finely becoming established. It is not hardy north of zone 6 for the first few winters so in those climates approapriate winter protection should be given until the plant hardens. Free of pests or disease.
Smaller trees transplant much better. Propagation is from seed in autumn or softwood cuttings taken in summer as well as tissue culture. Seedlings which are normally slow, grow like weeds under florescent light. Root prune seedlings to make transplanting easier later on.

* photos taken on July 2 2010 in Columbia, MD

* photo take on July 17 2010 @ Morris Arboretum, Philly, PA

* photo taken on Oct 25 2011 in Columbia, MD

* photo taken on Oct 30 2011 in Columbia, MD

* photos taken on Oct 21 2014 @ U.S. Botanical Gardens, Washington, DC

* photos taken on Apr 1 2016 in Catonsville, MD

* photos taken on Oct 6 2016 in Burtonsville, MD

* historic archive photo