Sunday, January 17, 2010

Amorpha - False Indigo

A genus of 15 species of shrubs that are part of the larger Legume family and are native to North America.
They prefer full sun to partial shade on just about any well drained with sufficient summer moisture. They are rabbit and deer resistant. Propagation is from the hard seeds which should be sandpapered before sowing. The seeds can also be treated by soaking in sulfuric acid for 8 minutes then left in hot water. Cultivars can also be reproduced from hardwood cuttings in winter or half hardened cuttings taken in summer.

* photo of unknown internet source



Amorpha californica ( California Indigo )
A medium size shrub reaching a maximum height of 13 feet, that is native to California.
The pinnate leaves, up to 8 inches in length, are composed of up to 25 leaflets, up to 1.5 inches in length.
Hardy north to zone 6

Amorpha canadensis
A small shrub native from Saskatchewan to Michigan; south to northern Mexico, Texas to Indiana. Some records include: largest on record - 4 x 5 feet.
The pinnate leaves, up to 5 inches in length, are composed of up to 45 leaflets, up to 1 inch in length.
The flowers are borne in panicles up to 6 inches in length.
Hardy zones 2 to 6, very drought and salt tolerant.

Amorpha canescens ( Lead Plant )
An upright, rounded, small shrub to around 3 feet that is native to dry sandy prairies and open woodlands from Saskatchewan to Manitoba to Lake Erie; south to New Mexico, Texas to Arkansas to Indiana.
Some records include: 3 years - 3 feet; largest on record - 5 x 5 feet.
The pinnate leaves, up to 6 inches in length, are composed of up to 51 leaflets, up to 1 inch in length. The foliage is silvery-gray due to the fine covering of hairs.
The leaves turn dull yellow during autumn.
The leaves can be used to make a pleasant tea, and were by the Oglala Indian Tribe.
The purple flowers are borne in dense narrow clusters, up to 10 inches in length, from June to August.
Hardy zones 2 to 6 in full sun on well drained soil. The deep root system reaching up to depths of 4 feet contribute to its extreme drought tolerance. Prune back every other year to keep it from becomming leggy.

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




* photo of unknown internet source

* photos taken on June 30 2013 @ U.S. National Arboretum, DC

* photo taken on July 11 2014 in Washington, DC


Amorpha fruticosa ( False Indigo )
A fast growing large shrub native to river valleys and prairies in central and eastern North America. It sometimes forms widespreading thickets on floodplain soils.
Some records include: first year from seed - 24 inches; Some records include; fastest recorded growth rate - 3 feet; 3 years - 4 feet; 6 years - 7 feet; largest on record - 20 x 40 ( usually half that ) feet
The pinnate leaves, up to 12 inches in length, are composed of up to 33 oblong leaflets, up to 2 x 0.5 inches. The foliage is bright to medium green.
The small deep flowers are borne in bottlebrush panicles up to 10 inches in length, during late spring and early summer.
Hardy zones
Hardy zones 3 to 9, tolerating as low as -40 F and grows very well on poor dry soils.

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





* photo of unknown internet source

* photos taken on June 30 2013 @ U.S. National Arboretum, DC

* USDA-NRCS PLANTS Database / Herman, D.E., et al. 1996. North Dakota tree handbook

* photo taken by Jennifer Anderson @ USDA-NRCS PLANTS Database


'Albiflora'
White flowers

'Coerulea'
Pale blue flowers.

Amorphha nana ( Fragrant False Indigo )
A small shrub only reaching up to 1.5 feet, that is native to dry prairies from Saskatchewan to Manitoba, south to New Mexico to Oklahoma and Iowa. Some records include: largest on record - 5 x 4 feet. It is a great plant to mix with dwarf conifers.
The pinnate leaves, up to 4 inches in length, are composed of 7 to 41 soft-spine tipped leaflets, up to 0.8 inches in length. The foliage is vibrant lush green.
The bluish-violet to purple flowers, up to 0.3 inches wide, are borne in sprays, up to 6 inches in length, during summer.
The young stems are finely hairy at first, turning to red-brown.
Hardy zones 2 to 8

* USDA-NRCS PLANTS Database


Amorpha nitens
A medium size shrub native to the southern U.S., reaching a maximum height of 10 feet.
The pinnate leaves, up to 8 inches in length, are composed of 7 to 19 oblong leaflets, up to 3 inch in length. The foliage is glossy deep green.
The flowers are red to mauve.
Hardy north to zone 7

Amorpha ouachilensis ( Ouachita Leadplant )
A small to medium size shrub reaching a maximum size of 6 x 6 feet, that is native to the Ouachita Mountains of central Arkansas where it is endangered.
The foliage is gray-green and the purple flowers are borne in narrow clusters, up to 8 inches in length, during late spring.
Hardy zones 5 to 7 on dry, well drained soil.

3 comments:

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  2. am growing Amorpha Fruticosa. (Started from seed last year. Now reaching about 3 ft). I have 5 plants, which doesn't mean I'll keep them all. It does tend to run, doesn't it ?

    I'm trying to find a spot for them in the garden. I see they can get quite big. I might experiment with trimming but am wondering if it's worth it. What's the life expectancy, do you know ?

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  3. I suspect their life expectancy is very long though I have not seen any exact statistics. It is quite possibly that individual clones may sustain themselves for over a century. I wouldn't be surprised they resprout from the rootstock after forest fires. For smaller sites I recommend Amorpha nana and canescens.

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