Wednesday, April 14, 2010

Jacobs Ladder

Polemomium
A genus of very attractive perennials for northern temperate regions.
They prefer partial shade on fertile, humus-rich, moist, well drained soil.
Deadheading will prolong bloom. Propagation can be achieved from sowing seed with a soil temperature of 70 F. They will take about a month to germinate. Another method of propagation is division done during late summer or very early spring. Insect pest and disease problems are rare though leaf spot, rust and powdery mildew may sometimes occur.

* photo taken on Apr 27 2015 in Elkridge, MD


Polemonium 'Blue Pearl'
A long lived perennial, reaching up to 16 inches x 2 feet, with excellent foliage all season long.
The blue flowers are borne on stalks that do not need staking.
Hardy zones 3 to 8 in full sun to partial shade.

Polemonium boreale ( Northern Jacob's Ladder )
A perennial, native to northwestern North America ( from far northern Alaska to far northwest Northwest Territories; south to Bella Coola, British Columbia to Dawson Creek, B.C. ).
The leaves are composed of up to 23 leaflets.
Hardy zones 2 to 5 in full sun to partial shade.

* photo taken on June 22 2013 in Columbia, MD


'Heavenly Habit'
A moderate growing, upright, long lived perennial, reaching up to 14 inches x 1.5 feet.
The flowers are violet-blue with a yellow eye. Will often rebloom if cut back after flowering.
Hardy zones 2 to 5.

* photo taken on Apr 6 2013 in Columbia, MD

* photo taken on June 10 2014 in Clarksville, MD


Polemonium caeruleum ( Jacob's Ladder )
A long-lived, clumping perennial, reaching up to 4 x 3 feet, that is native to woodlands and meadows of temperate Europe into northern Asia.
The pinnate leaves, up to 16 inches in length, are composed of 11 to 27 oblong leaflets, up to 1.6 x 0.6 inches in size. The mid to deep green foliage clump is evergreen in mild climates.
The blue, saucer-shaped flowers, up to 1.3 inches across, are borne in spikes during late spring through late summer.
Hardy zones 2 to 7 in full sun to partial shade on moist, fertile, alkaline to neutral, well drained soil.
Prefers cool summers.
Propagation is from seed and if may self seed on occasion.

* photo of unknown internet source

* historic archive photo


'Album'
Flowers are white.

'Brise d'Anjou'
Reaching up to 3 x 3 feet with strikingly variegated foliage that is deep green and edged with creamy-white.
The violet-blue flowers are borne during early summer.
Great for use in the shaded garden for edging and in containers.

'Snow & Sapphires'
Vigorous and long lived, reaching up to 31 x 16 inches. The large deep green leaves is boldly edged in clean creamy-white variegation.
The sky-blue flowers are fragrant as far away as 5 feet away.
Deadheaded plants may blooms 3 times in a season.

* photo taken on May 7 2012 in Columbia, MD

* photo taken on May 17 2013 in Columbia, MD

Polemonium carneum ( Royal Jacobs Ladder )
A rhizomatous, clumping perennial, reaching up to 4 x 2 ( rarely over 3 ) feet, that is native to the western U.S. ( far northern Washington State to central California ).
The pinnate leaves, up to 8 inches in length, are composed of up to 21 elliptic leaflets, up to 1.6 inches in length. The foliage is mid-green.
The pink, cup-shaped flowers, up to 1 inch wide, are borne late spring to mid-summer.
Hardy zones 3 to 8 in full sun to partial shade on moist, humus-rich, well drained soil. It is tolerant of summer drought.

'Pink Beauty'
Purplish-pink flowers.

Polemonium cashmerianum ( Kashmir Jacob's Ladder )
A perennial, reaching up to 3.5 feet, that is native to the Himalayas. It is considered by some to be a subspecies of Polemonium caeruleum.
The pinnate leaves are deep green.
The lavender-blue, bell-shaped flowers, up to 1.5 inches wide, are borne on upright spikes during early summer.
Hardy zones 4 to 8 in full sun to partial shade on moist, fertile, well drained soil.

Polemonium confertum ( Rocky Mountain Jacobs Ladder )
A perennial, reaching up to 1 foot, that is native from southwest to central Colorado, that is native to rock ledges and mountain meadows at high elevations of 11 000 + feet.
The intensely mid-blue flowers are borne on densely-rounded, tennis ball sized clusters during mid-spring.
Hardy zones 2 to 6 on sandy, very well drained soil.

* historical archive photo


Polemonium foliosissima ( Towering Jacob's Ladder )
A very long lived perennial, reaching a maximum size of 3.3 x 3 feet, that is native to the Rocky Mountains ( from northern Idaho to western Wyoming; south to Nevada to New Mexico ).
The pinnate leaves are composed of up to 24 oblong or elliptical leaflets.
The lavender-blue or white, cup-shaped flowers, up to 0.6 inches long, are borne from early summer to early autumn.
Hardy zones 4 to 8

Polemonium humile
A perennial, reaching a maximum size of 2 feet x 20 inches, that is native to Siberia.
The bright blue, saucer-shaped flowers, up to 0.3 inches across, are borne late spring into early summer.
Hardy zones 3 to 8

Polemonium occidentale ( Western Polemonium )
A perennial, reaching up to 40 inches, that is native to western North America ( from British Columbia to Alberta; south to northern California to northern New Mexico ). There is also a separate population in Minnesota and Wisconsin next to Lake Superior.

* photo taken by Mr. & Mrs. Robert G. Young @ USDA NRCS. 1992. Western wetland flora

* photo taken by Jean Pawek @ CalPhotos


Polemonium pauciflorum
A perennial, reaching up to 20 inches in height, that is native to mountains from southeast Arizona into northern Mexico.
The pinnate leaves are composed of lance-shaped leaves. The foliage is mid-green.
The hanging, bright yellow flowers, up to 1.6 inches in length, are borne during summer.
Hardy oznes 6 to 8 in full sun to partial shade on moist, well drained soil.

Polemonium pulcherrimum ( Showy Polemonium )
A rhizomatous, erect, clumping, perennial, reaching up to 2 x 2 feet, that is native to northwest North America ( from northwest Alaska to northern Yukon to western Northwest Territories to Calgary, Alberta to central Wyoming; south to central California to northern New Mexico ).
The pinnate leaves, up to 4.5 inches long, are composed of 9 to 27 oval leaflets up to 0.6 x 0.2 inches in size. The finely hairy foliage is bright green.
The blue or violet ( rarely white ) flowers, up to 1 inch wide, are borne on dense clusters from late spring into summer.
Hardy zones 2 to 7 in partial shade on fertile, light, well drained soil.

* historical archive photo

* photos taken by Jean Pawek @ CalPhotos


Polemonium reptans ( Creeping Jacob's Ladder )
A long-lived, spreading, semi-evergreen perennial, reaching a maximum size of 32 x 27 ( rarely over 15 ) inches, that is native to moist rich forests and floodplains in eastern North America ( from eastern South Dakota to central Minnesota to central Wisconsin to southern Michigan to southern Ontario to southeast Quebec & New Hampshire; south to eastern Oklahoma to central Alabama to Virginia ). It is endangered in Kansas, Nebraska, Michigan, New Jersey, Delaware, North Carolina, Georgia and Mississippi. In the Windsor/Essex County, Ontario region; it is only known from the Ohio shore where uncommon but not quite rare. The clumps become woody and thick as plants age. It is an excellent easy to grow perennial for the woodland garden.
The pinnate leaves, up to 10 inches in length, are composed of 7 to 19 oblong leaflets up to 1.6 inches in length.
The attractive foliage is luxuriant bright green, later turning to deep green above, silvery-green below.
The fragrant, drooping, blue, saucer-shaped flowers, up to 0.6 inches across, are borne in sprays during mid-spring to early summer. The flowers attract butterflies.
Hardy zones 2 to 8 in partial to full shade on moist, humus-rich, well drained soil that is mulched. Rarely bothered by deer, pests or disease.
Deadheading may encourage reblooming.
Propagation is from seed or division every 5 years.

* photo taken on April 11 2010 @ U.S. National Arboretum

* photos taken on Apr 12 2017 in Columbia, MD

* photo found on internet

* historic archive photo

* photos taken on May 27 2017 @ Meadowlark Botanical Gardens, Vienna, VA


'Album'
White flowers.

'Blue Pearl'
Great variety with deep green foliage that remains luxuriant all season long.
Low growing, it reaches a maximum size of 1 x 2+ feet.
The flowers are bright blue.

'Lambrook Mauve'
Forms a mound up to 2 feet in height with lilac-blue flowers.

'Stairway to Heaven'
Moderately fast growing, reaching up to 1.7 foot in height with luxuriant green foliage that is boldly edged in pinkish-white later turning to white variegation.
The flowers are lavender-blue.
Looks great mixes with purple leaves Heuchera and large blue foliaged Hostas.
It is one of the few variegated Polemoniums that thrive in the heat and humidity of the Mid Atlantic region of the U.S.

* photo taken on July 13 2011 in Columbia, MD

* photo taken on Aug 1 2013 @ Stratford, Ontario

* photos taken on May 3 2014 in Baltimore Co., MD


'Touch of Class'
More vigorous than the similar looking 'Stairway to Heaven' and low growing, reaching about 14 inches in height. The foliage is green with a narrow white margin.
The pale blue flowers are borne mid spring to early summer.
Cut back immediately after flowering to get a nice flush of attractive summer foliage.

* photo taken on May 3 2014 in Baltimore Co., MD

* photo taken on June 25 2017 in Elkridge, MD


Polemonium x richardsonii
A rhizomatous perennial, reaching a maximum height of 2 feet, with violet-blue flowers, up to 1 inch wide. It is the hybrid of Polemonium caeruleum & P. reptans.
Hardy zones 2 to 7 in full sun to partial shade on moist, humus-rich, well drained soil. Propagation is from division.

Polemonium yezoense ( Japanese Jacob's Ladder )
A perennial, reaching up to 32 inches x 2 feet, that is native to northern Japan.
The pinnate leaves are composed of 19 to 25 leaflets. The attractive, finely-divided, ferny foliage is luxuriant glossy mid to deep green.
The large blue flowers, up to 1 inch long, are borne in clusters over a long season from late spring into early summer.
Hardy zones 3 to 7 in full sun to partial shade. Deer resistant.

'Purple Rain'
Foliage and stems are purple; otherwise the same.

* photo taken by Milan Havlis ( havlis.cz )

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