Frasera spp.

green gentian

SunFull Sun – Part Shade

HardinessZones 3–7

Overview

Frasera is a genus of about 14 species of stout, monocarpic perennials in the gentian family (Gentianaceae), native to North America and most diverse in the mountains and high plains of the western United States. Plants spend several to many years as a low basal rosette of long, smooth leaves, then send up a single tall flowering stalk, set seed, and die. In the well-known F. speciosa (monument plant or green gentian), the flowering stalk reaches 3-6 feet (0.9-1.8 m) and bears whorls of leaves and many four-petalled flowers that are greenish-white to pale yellow, dotted with purple and marked with fringed nectar glands. The seeds are flattened and held in dry capsules. Frasera grows in meadows, open woodland, sagebrush, and rocky slopes, often at moderate to high elevation. Because plants are monocarpic, an individual flowers only once after a long juvenile period, and whole populations sometimes bloom heavily in the same year. The long wait to bloom and the death of the plant after flowering limit its use to naturalistic and native plantings.

Native Range

Frasera is native to North America, ranging across the western United States into northern Mexico and, in a few species, eastward in North America. F. speciosa grows in mountain meadows and sagebrush of the Rocky Mountains and Great Basin.

Suggested Uses

Frasera is grown in native, meadow, and rock-garden plantings and in restoration of montane and sagebrush habitats. The tall flowering stalks of F. speciosa add vertical structure to naturalistic plantings in the years they appear. It is used mainly by native-plant growers, given the long wait between germination and bloom.

How to Identify

Recognized by a large basal rosette of long, smooth, strap-shaped leaves, and, in flowering plants, a tall single stalk with whorls of leaves and many four-petalled flowers. The greenish-white to pale yellow flowers are dotted with purple and bear fringed nectar glands on the petals. The combination of a stout monocarpic rosette and a tall, leafy flower stalk separates Frasera from true gentians (Gentiana), which are usually low and blue-flowered.

Appearance

Size & Dimensions

Height3' - 6'

Width/Spread1' - 2'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~4 weeks

Spring Summer

Flowering occurs in late spring and summer, roughly May to August depending on elevation. Each plant blooms only once, after years as a rosette, then dies. The many nectar-glanded flowers draw bees, wasps, flies, and other insects.

Detailed Descriptions

Flower Description

greenish-white to pale yellow, purple-dotted

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 5-10 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 rocky sand

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

Several years (monocarpic)

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Frasera grows in full sun to light shade in free-draining, gritty or loamy soil, and tolerates cold, drought, and lean ground typical of its montane habitats. It is grown from fresh seed sown in autumn, as the long taproot makes transplanting of older plants difficult. Plants need a cold winter period to germinate and several seasons of rosette growth before flowering. Watering is needed only to establish seedlings, after which plants rely on natural rainfall in suitable climates. Because each plant dies after flowering, a self-sown patch is maintained by leaving some seed heads to ripen. Few pests or diseases affect it.

Pruning

No routine pruning is needed for this monocarpic plant. The dead flowering stalk is cut down after seed ripens, by which time the plant has finished its life cycle. Some seed heads are left in place to allow self-sowing.