Amorpha fruticosa is a deciduous shrub native to North America; also widespread in Europe, in the wild, where it was originally imported as an ornamental plant. It has a rounded shape, is very branched and reaches even 2-3 meters in height; the leaves are composed, consisting of 29-35 small oval leaves, bright green, slightly lighter on the lower side; the bark of the short stem is greyish, smooth. At the end of spring and late in late summer it produces long spikes consisting of numerous dark purple-red flowers, with showy golden-yellow or orange anthers; at the end of summer the flowers are succeeded by fruits, small green, shiny pods, which become red or brown when ripe, in autumn. The plants of Amorpha they tend to produce numerous basal shoots and therefore the bushes can become very large, colonizing all the space they have available; if you intend to keep the shrub within a restricted area it is good to periodically remove the suckers.
Amorpha fruticosa is a plant that develops best if placed in the ground, but can have satisfactory growth even if grown in pots. These plants should be planted in a very sunny place; these shrubs can also bear partial shade, but they receive direct sunlight for at least a few hours a day.
They do not fear the cold, even if it is advisable to place them in a place sheltered from the wind, so as to prevent the long spikes of flowers and fruits from being damaged. If the climate is particularly stiff it is good to cover the aerial part, or, if placed in a vase, shelter them in a sheltered place.
The plants of Amorpha fruticosa can also withstand periods of drought but, from March to September, it is good to intensify watering and watering about once a week, to allow the plant a balanced development. During the winter period it is necessary to thin out watering sensitively. It is good to take care to check that water does not form at the base of the plant.
At the beginning of spring bury at the foot of the shrub with mature organic fertilizer, or spread a handful of slow-release granular fertilizer around the trunk.
The plants of Amorpha fruticosa have been shown to be able to adapt to any soil, even poor and stony; undoubtedly for a better development of the plant it is good to put it in a good rich soil and above all very well drained soil, with the addition of sand and lapillus or pumice stone. The best soil is composed of peat, sand, soil, organic substances and pumice stone.
The multiplication of this variety of plants occurs by seed, in spring, after stratifying the seeds in the refrigerator for at least a week; in autumn or at the end of winter it is also possible to remove the basal suckers, which must be rooted in a mixture of peat and sand in equal parts, in a container or directly at home; young plants should be kept in a partially shady place for the first year, and they should be watered regularly.
Amorpha fruticosa: Pests and diseases
Plants of this genus are quite resistant and are hardly attacked by diseases; sometimes, however, the aphids infest the ears of flowers and compromise the splendid flowering of the plant. To prevent this from happening it is advisable to intervene with specific products at the end of winter, before the plants begin to bloom.