The potato bush plant is an attractive shrub that grows up to 6 feet (2 m.) tall and wide. It is evergreen in warm climates, and its dense growth habit makes it suitable for use as a hedge or screen. You can also grow it as a tree by removing the lower branches. Pinching the tips of new growth encourages bushiness.
What is a Potato Bush?
The potato bush plant (Lycianthes rantonnetii), a native of Argentina and Paraguay, is best suited to the frost-free climates found in U.S. Department of Agriculture plant hardiness zones 10 and higher. A member of the Solanum family, it is closely related to potatoes, tomatoes, and eggplants, but you should never eat it because it is poisonous. Common names for this plant include blue potato bush, Paraguay nightshade, and blue solanum shrub.
Potato bush plant is grown outdoors in warm climates. In areas with cool winters, grow it as a potted plant that can be brought indoors when frost threatens. In cool areas, an abundance of small, blue flowers bloom in summer and fall. In frost-free areas, it blooms year round. The flowers are followed by bright red berries.
Potato Bush Growing Conditions
Blue potato bush needs a sunny location and a frost-free climate. The plant prefers an organically rich soil that is constantly moist, but well-drained. Achieve the right balance of moisture by watering the plant slowly and deeply when the surface feels dry. Apply a layer of mulch over the soil to slow water evaporation. If the soil drains too quickly, work in some organic material, such as compost.
Potato bushes grow best if fertilized regularly. You can use a 2-inch (5 cm.) layer of compost once or twice a year; a complete, balanced, slow-release fertilizer in spring and late summer; or a liquid fertilizer once every month or two. Compost helps the soil manage water efficiently.
Avoid growing a blue potato bush in areas where children play, as they may be tempted to put the bright red berries in their mouths.