Saturday, April 9, 2011

Oleander

Nerium oleander
This is the more popular of only 2 species of evergreen shrubs or trees in the Nerium genus which is part of the larger Dogbane family. It is native from southwest Asia into China but is very commonly grown in the region around the Mediterranean Sea. Variable in habit, the fast growing Oleander typically is multi-stemmed, bushy and erect in habit, reaching around 15 feet if left unpruned. Some records include: largest on record - 35 x 36 feet with a trunk diameter of 1.7 feet; 1st year - 5 feet; 7 years - 15 feet ( avg ); fastest recorded growth rate - 5 feet.
The smooth-edged, lance-shaped leaves are up to 12 x 1.5 inches in size.
The leathery foliage is deep green above, paler green beneath.
The evergreen leaves are borne in whorls of 3.
The white, pink, rose, salmon-orange or red flowers, up to 2 inches across, are borne in terminal clusters from late spring through early autumn then more sporadically into early winter.
The bark is dark brown.
Hardy zones 8 to 12 in full sun on fertile, well drained soil. Tolerant of dry sandy soil and salty sea breezes making it an excellent plant for the ocean shore as well as along highways. Tolerant of temperatures somewhat below freezing if on a site protected from excessive wind.
Oleanders prefer hot dry summers and grow well in Mediterranean climates though a mulch of stone to cool soil and retain moisture during summer will improve growth.
They are NOT eaten by deer but may be prone to scale on some sites.
The Oleander may be trained as a tree but it can also be kept as a dense shrub if pruned back hard approximately every 3 years once established. All Oleanders have improved vigor if old flower clusters are deadheaded.
Propagation is from semi-ripe cuttings taken during summer.
Pharmacology: entire plant is poisonous - DO NOT EAT! It is also recommended to wear gloves while pruning.


* photos taken in south Florida on Jan 3 2011







* photos of unknown internet source




* photo taken on Aug 15 2014 @ Druid Hill Park, Baltimore, MD

* photo taken @ Smithsonian Inst, Wash., DC on Aug 25 2014


'Album'
Flowers are single and white.

* photos of unknown internet source



* historic archive photo


'Algiers'
Deep red flowers.

'Calypso'
Reaches a maximum size of 20 x 15 feet.

'Casablanca'
Pinkish-white flowers

'Delphine'
Deep purplish-red, single flowers.

'Dicteur Golfin'
Purplish-pink, single flowers.

'Hardy Pink'
Reaches a maximum size of 12 x 10 feet, with yellow flowers.
It is among the hardiest of all Oleander and has even survived -9 F grown as a perennial in central Ohio, reaching up to 6 feet.

'Hardy Yellow'
Reaches a maximum size of 12 x 10 feet, with yellow flowers.
It is among the hardiest of all Oleander and has even survived -9 F grown as a perennial in central Ohio, reaching up to 6 feet.

'Madonna Grandiflora'
Flowers are double and white.

'Petite Pink'
A compact form, reaching a maximum size of only 10 x 6 ( rarely over 5 ) feet, with bright pink flowers. Slow to moderate growing and shrubby, it typically reaches about 4 feet in 10 years.

'Petite Salmon'
Reaches a maximum size of only 10 x 6 ( rarely over 5 ) feet, with salmon-pink flowers. Slow to moderate growing and shrubby, it typically reaches about 4 feet in 10 years.

'Splendens'
Double, deep rose-pink flowers.

'Variegata'
Reaches a maximum size of 20 x 15 feet with attractive foliage variegated with a creamy-yellow margin. The flowers are double and pink.

* photos taken on Aug 15 2014 @ Rawlings Conservatory, Baltimore, MD


'Wilmington Pink'
Among the most hardy of all cultivars, north to zone 7b if on a sheltered site.

1 comment:

  1. Great plant to have around for borders and privacy.....lush, green, and low maintenance once established. Love sun, but roots can be a problem if near a foundation or pipes.

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