River Locust
Amorpha Fruticosa

River Locust, Blue False Indigo Bush, Amorpha Fruticosa. Different names for the same beautiful plant. Yes, this is definitely a member of the Pea family, Fabaceae. This is not Black Locust, and not the Blue False Indigo that many people grow as an herbaceous perennial that gets 3’ tall. This is a super hardy woody shrub that grows to 12’. The flowers this shrub produces are jaw droppingly beautiful, sometimes 8” long clusters of flowers ranging from royal purple to almost gold. Honey bees in particular lose their minds with the nectar flow, but the flowers are small enough that a wide cast of flying characters congregate and enjoy as well.

We’re just getting to know this amazing support ally plant, and have begun planting them widely in our landscape. Tolerant of incredibly wet positions, we’ve seen them naturalize along shorelines and water ways, fixing nitrogen, holding soil, and flowing nectar and beauty back into the landscape. We’re planting them as early succession support shrubs to fuel soil growth and support over story trees like Mulberry, Chestnut, Apples and the like. Closely planted early on to fix N and stimulate upward growth of the ‘keystone’ tree and then pruned back hard as needed to provide woody Alfalfa like green mulch.
Unlike it’s powerhouse friend the Black Locust, this shrub does not present sharp thorns or a suckering and spreading habit. We find it very responsive in positive ways to pruning both during dormant season and in the active growth season. The deer seem to enjoy the foliage, so we are interested to learn more about it’s value as a fodder crop for other animals. The wood seems strong and dense, so perhaps it can also add some small gauge firewood production to it’s long list of values!

Our offering is of 1st year seedlings, grown in rich soil at dense spacing. We grade the plants out to provide 6” of top growth minimum (generally 1’ or taller) with a healthy root system, and are offering ‘self-nursery’ bundles of many more smaller plants that you can grow out yourself and save some money! We find cutting back growth after the 1st year helps them really explode with growth when you get them so depending on our time and discretion you may get 1st year seedlings ‘headed back’ to maximize establishment. Some years the rabbits help us with a lovely heading back pruning mid winter. We’ve come to appreciate it actually!!! Expect the smaller plants to need 1 good year in a nursery bed before setting out to field or thoughtful mulch and weeding in final positions if you want to plant out directly.

We also now have good numbers of much larger plants ready to find homes. Many of the 2nd year River Locust plants are at least 2’ tall and very very well developed in the roots. We have single and 3 pack options of these. We will have to cut the tops a bit to fit in boxes but they are very positive responders to pruning!

Size:
Tops out at 12’ or so, and can be coppiced, pollarded, pruned and managed to be any size below that. Very amenable to pruning.

Site Preference:
Enjoys full sun and can tolerate an incredibly wet position. We have some shrubs growing in competitive and shady conditions that are upright, happy and flower heavily, so it seems very very adaptable.

Hardiness:
Zone 4-9 (perhaps colder where they may die back to the ground in some winters but rebound in spring)