Lycianthes spp.

blue potato bush and relatives

Solanaceae

Tropical and subtropical Americas and Asia

Attracts Pollinators Drought Tolerant Container Friendly

Native to North America

SunFull Sun

WaterMedium · drought-tolerant

HardinessZones 9–11

Overview

Lycianthes spp. is a genus of about 200 species of shrubs, subshrubs, climbers, and herbs in the nightshade family, native to the warm regions of the Americas and of eastern and southern Asia. The genus is closely related to Solanum spp. and was long included within it. Plants carry simple leaves, often paired with one large and one small leaf at each node, and star- or wheel-shaped flowers with five spreading lobes in violet-blue, purple, or white, usually with a ring of green or yellow markings at the center. Small round berries follow, ripening red, orange, or black. The blue potato bush (L. rantonnetii, once Solanum rantonnetii) is grown as a flowering shrub for its long season of violet-blue bloom. The genus is frost-tender and is cut back or killed by frost. As members of the nightshade family, the leaves and unripe berries contain alkaloids and are toxic if eaten.

Native Range

Lycianthes spp. is found in the tropics and subtropics of the Americas, from Mexico and the Caribbean through Central America to South America, and again in eastern and southern Asia. Species grow in forest edges, clearings, scrub, and disturbed ground. The widely grown L. rantonnetii comes from South America, in Argentina, Paraguay, and Brazil.

Suggested Uses

Grown as a flowering shrub, informal hedge, container plant, or standard (lollipop) in warm gardens, and under glass in regions with cold winters. The long bloom season suits mixed borders and patio pots. Plants are spaced 3 to 6 feet (0.9 to 1.8 m) apart.

How to Identify

Recognized by nightshade-type, star- to wheel-shaped flowers with five pointed, spreading lobes and a central cone of yellow anthers, set against simple leaves that are often unequal in pairs at each node. The flowers lack the toothed calyx teeth seen in Solanum spp. and instead have a calyx with ten small projections, a key feature of the genus. Round berries follow the flowers.

Appearance

Size & Dimensions

Height3' - 10'

Width/Spread3' - 8'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~16 weeks

Spring Summer Fall

In warm climates flowering runs over a long season from spring into fall, and nearly year-round where frost is absent, with L. rantonnetii flowering almost continuously. The wheel-shaped flowers open in succession over many weeks. Light pruning and feeding keep the flush of bloom going.

Detailed Descriptions

Flower Description

violet-blue, purple, or white

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.5(Neutral)

357912

Soil Types

loam sand

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

tender

Time to Maturity

Reaches mature size in 2 to 4 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in full sun and moist, fertile, well-drained soil and flower most freely in warm weather with regular water and feeding. Established plants tolerate short dry spells, but prolonged drought reduces flowering. The genus is frost-tender; in cold regions plants are grown in containers moved under cover or treated as summer container plants. Stems are soft and can grow lank, so plants are pinched or staked to stay full. Whitefly, aphids, and spider mites are the main pests under glass.

Pruning

Pruning keeps shrubby species dense: stems are cut back in late winter or early spring, and long shoots are shortened through the growing season to control size and draw out flowers. Plants tolerate hard pruning and resprout from old wood. Climbing species are trained and thinned on their support.