Sunday, August 1, 2010

False Indigo - Amorpha fruticosa

False indigo, or leadplant, (Amorpha fruticosa) is a deciduous woody shrub native to moist soil habitats, such as stream banks, throughout Florida and much of North America.  This relatively common native plant eventually can reach heights of 12 feet on stems with diameters of 1 inch or more.  Because of their large size, they need to be placed in a landscape where they have ample space.
False indigo loses its leaves in early winter and remains leafless until spring.  At this time, it produces both its compound leaflets and its wonderful flower spikes.  The leaflets are composed of many elliptical opposite leaves which give the plant a feathery appearance.  This foliage keeps the plant looking attractive throughout the summer, even when it is not in bloom, and serves as a larval food source for two butterflies - the southern dogface sulphur and the silver-spotted skipper.  Though both of these butterflies are not common to urban landscapes and are, therefore, not likely candidates for butterfly gardens in highly developed areas, using this wonderful shrub is worth the effort.
What makes false indigo special is its floral display in mid-spring.  At this time, its crown is literally covered with 2-3 inch flower spikes.  Each bloom is a deep purple in color and the bright orange anthers contrast sharply with the purple floral tubes.  False indigo is an excellent butterfly nectar plant, and also attracts bees and other pollinators. 
Although this plant occurs naturally mostly in moist soils in Florida, it is extremely adaptable and can be successfully grown in most home landscape settings.  We have kept ours in nearly full sun and very poor droughty soil for a great many years and it has thrived.  It is best used, however, in moist soil with full sun or in partial sun in droughtier locations.  Plant it at the back of a planting bed.  As it matures, smaller wildflowers can be planted beneath it as it does not throw too much shade.
False indigo is easy to propagate from seed and is available from a number of commercial nurseries statewide.  It grows rapidly.

1 comment:

  1. Hi Craig; I love your site! Thank you for providing yet another helpful tool for self-educating native plant enthusiasts like me! My husband and I have been "fans" of yours since you were the Urban forester for Pinellas County (I called you a thousand years ago - really around 2-3 decades ago - about a lovely square-stemmed pink flowering "weed" taking over my Grandmother's rose garden - it turned out to be Stachys floridana, and you humorously suggested that I "control" the "betony" by learning to like the taste of it, and gradually "harvesting and eating it out of the rose garden." I pretty much abandoned "formal" gardening shortly therafter (in my early twenties) and have cultivated natives and permaculture landscapes ever since (I'm now in my late forties).
    Regarding your page on Amorpha fruticosa: I have noticed it growing along a fence line of a state-owned scrub parcel, along side Vaccinium arboreum, Lyonia ferruginea, Lonicera sempervirens, smilax, a variety of scrub oaks, etc. in a fairly typical coastal scrub habitat, complete with Gopher Tortoise burrows, sand pine, Osmanthus, Asimina, typical white sandy soils, but no rosemary) - NOT a wetland, but down slope from a Sandhill to its east, and uphill from a springs coast forested wetlands to its northwest. The parcel has lithic scatter and other plants that "former" populations would have considered medicinal or useful. My "subject" has typical deep purple-indigo flowers. It's under a powerline; so perhaps "bird planted," but still, robust and thriving (subject in bloom today was substantially taller than my 5'2" self) in what most would consider "upland" habitat. Most Florida botanical references list Amorpha fruticosa as FACW (a wetland species). I noticed that you also have found A. fruticosa to be highly adaptable to dry soils and persistent droughty periods (like the one we're presently suffering). Perhaps the "gods of botany" might consider moving it to "FAC?"


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