1 / 9

Oxalis montana

mountain woodsorrel

Oxalidaceae

Northeastern North America and Appalachian Mountains

Attracts Pollinators

Native to North America

SunPart Shade – Full Shade

WaterHigh

HardinessZones 3–7

Overview

Oxalis montana is a low, creeping woodland perennial in the woodsorrel family, forming mats 2-6 inches (5-15 cm) tall from slender, scaly rhizomes. Each leaf is divided into three heart-shaped leaflets 0.4-0.8 inch (1-2 cm) wide that fold downward at night and in bright sun, a movement called nyctinasty. Flowers are borne singly on thin stalks above the foliage, 0.5-0.8 inch (12-20 mm) across, with five white petals veined in pink to rose and notched at the tips. These open flowers are followed later in summer by closed, self-pollinating cleistogamous flowers near the ground that set most of the seed. Seed capsules split and eject seeds a short distance when ripe. O. montana spreads slowly into colonies across the floor of cool, moist conifer and mixed forests, forming a continuous green carpet. It requires consistent moisture and deep shade and declines quickly where the canopy opens or the soil dries, which limits its use to shaded, humus-rich sites. The foliage carries a sour, oxalic taste and dies back to the rhizome over winter.

Native Range

Oxalis montana is native to northeastern North America, from eastern Canada south through the Appalachian Mountains, and across boreal and montane conifer forests. It grows in cool, moist, shaded woodland with acidic, organic soils.

Suggested Uses

Oxalis montana works as a groundcover in shaded, moist woodland and native plant gardens. It pairs with ferns, trilliums, and other forest-floor species under conifers or hardwoods. The folding leaves and veined flowers add ground-level interest in cool shade gardens.

How to Identify

Look for clover-like leaves of three heart-shaped leaflets 0.4-0.8 inch (1-2 cm) wide that crease and fold along the midrib. The white flowers, 0.5-0.8 inch (12-20 mm) across, carry pink to rose veins and notched petal tips. Unlike yellow-flowered woodsorrels such as O. stricta, the petals are white and the plant lacks upright stems, growing flat from creeping rhizomes.

Appearance

Size & Dimensions

Height2" - 6"

Width/Spread1' - 1'6"

Reaches mature size in approximately 2 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~8 weeks

Spring Summer

White flowers open from late spring into midsummer, roughly May to July, one bloom per stalk above the leaves. Closed cleistogamous flowers form near ground level later in the season and produce the bulk of the seed. Cool, humid forest conditions extend the open-flower display.

Detailed Descriptions

Flower Description

white with pink veins

Foliage Description

green

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Shade

Tolerates up to 4 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 Range4.5 - 6.0(Acidic)

357912

Soil Types

loam peat

Drainagemoist

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

2-3 years

Care & Maintenance

Care Guide

Oxalis montana needs full to partial shade and steady soil moisture, matching the cool conifer forests it inhabits. Soil should be acidic, rich in organic matter, and never allowed to dry fully. It spreads by creeping rhizomes into open colonies but grows slowly and does not become aggressive. In cultivation it suits shaded woodland gardens and the north side of buildings where summer heat is moderated. Heat, drought, and direct afternoon sun cause rapid wilting and dieback. A surface layer of leaf litter mimics its natural rooting zone and conserves moisture.

Pruning

No pruning is needed. Dead foliage collapses to the rhizome in late fall and can be left in place as natural mulch. Spent flower stalks may be removed for tidiness, though reseeding relies on the later cleistogamous flowers.