Xanthisma spp.

sleepy daisy

Asteraceae

Southwestern North America (United States and Mexico)

Attracts Pollinators Attracts Butterflies Deer Resistant Drought Tolerant Container Friendly

Native to North America

SunFull Sun

WaterLow · drought-tolerant

HardinessZones 4–9

Overview

Xanthisma spp. is a genus of about 17 species of annual and perennial herbs in the daisy family, native to the dry plains, deserts, and foothills of the southwestern United States and Mexico. Plants form low, branching mounds 15-60 cm (6-24 in) high, with narrow, often toothed or spiny-margined leaves that can be green or grey-green and slightly resinous. The flower heads are 2-4 cm (0.8-1.6 in) across, most species carrying yellow ray florets around a yellow disc, though a few have purple or violet rays. Flowering runs through the warm season, and the heads of some species close in dull light or at night, the trait behind the name sleepy daisy. Most species grow on sandy, gravelly, or rocky soils in open sun and tolerate heat and drought once established. Several grow on mineral-rich soils and can take up selenium where it is present in the ground, a feature shared with related plains asters. The genus spans short-lived annuals and longer-lived perennials, so habit and hardiness vary by species. Wet, heavy, shaded conditions are poorly tolerated, and growth is sparse in rich or crowded plantings.

Native Range

The genus is native to North America, centred on the southern Great Plains, the Southwest, and the deserts and foothills of the United States and northern Mexico. Species grow on prairie, plains, mesas, and disturbed ground, usually on dry, well-drained soils. X. texanum of Texas and nearby states is one of the more widely grown species.

Suggested Uses

Used in dry, gravel, prairie, and wildflower gardens and on hot, sunny banks with sharp drainage. The yellow daisies suit pollinator and native plantings in the southwestern United States. Low species also suit containers and rock gardens.

How to Identify

Look for a low, branching daisy of dry, sunny ground with narrow, often toothed or bristle-edged leaves and yellow flower heads, or in some species purple-rayed heads, over a yellow disc. The heads of several species close in shade or at night. The combination of plains or desert habitat, resinous narrow leaves, and yellow daisy heads helps place the plant in Xanthisma spp..

Appearance

Size & Dimensions

Height6" - 2'

Width/Spread6" - 1'6"

Colors

Flower Colors

yellow

purple

Foliage Colors

green

Bloom Information

Bloom Period

~16 weeks

Spring Summer Fall

Flowering extends through the warm season, broadly spring to autumn depending on species and rainfall, with peaks after rain. Individual heads last several days, and plants flower over many weeks. In some species the heads close during dull weather and reopen in bright sun.

Detailed Descriptions

Flower Description

yellow, or purple in some species

Foliage Description

green to grey-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 - 8.0(Neutral)

357912

Soil Types

sand loam rocky clay

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

1 year to flowering

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in full sun on sandy, gravelly, or rocky free-draining soils, including poor and alkaline ground. Once established they tolerate heat and drought and need little water, while wet, heavy, or shaded sites cause weak growth and rot. Annual species are grown from seed sown in spring, and perennial species form longer-lived clumps. Feeding is seldom needed, as lean soil keeps growth compact. Hardiness varies, so the species is matched to the local winter. Few pests trouble them, though aphids can gather on soft growth and root rot follows poor drainage.

Pruning

Spent flower heads are trimmed to tidy the plant and extend bloom. Perennial species are cut back after flowering or in late winter to refresh the clump. Annual species need no pruning and are left to self-seed or are cleared at season's end.