Oxalis exilis
least yellow-sorrel
New Zealand and southeastern Australia
Overview
Oxalis exilis is a very small, creeping perennial 1-3 inches (2.5-8 cm) high, forming low, thread-like mats of slender stems that root as they spread. The clover-like leaves are tiny, divided into three heart-shaped leaflets each about 0.1-0.25 inch (3-6 mm) wide, green to bronze-tinged, and fold down at night. From spring into autumn it produces minute yellow flowers about 0.15-0.25 inch (4-6 mm) across, borne singly or in pairs on slender stalks, with five petals. The flowers are followed by narrow, upright seed capsules that, when ripe, split explosively and fling seed up to several feet, scattering it widely. It spreads by these flung seeds and by rooting stems, and quickly becomes a persistent weed of lawns, paths, gravel, greenhouse benches, and container plants. The plant grows in sun or part shade on most soils and tolerates close mowing, dry ground, and disturbance, regrowing from stem fragments and the seed bank. It is closely related to and often confused with Oxalis corniculata, differing in its smaller, more slender growth. Once established it is hard to remove, and the explosive seed and rooting stems make containment difficult.
Native Range
Oxalis exilis is native to New Zealand and southeastern Australia, where it grows in open, disturbed, and grassy ground. It has naturalised widely in Europe, North America, and other temperate regions as a garden and agricultural weed.Suggested Uses
Rarely grown on purpose, Oxalis exilis appears mostly as a weed of lawns, paths, gravel, and containers. Where tolerated, its low bronze-green mats fill cracks and bare ground in informal paving. It is otherwise treated as a weed to control.How to Identify
Appearance
Size & Dimensions
Height1" - 3"
Width/Spread6" - 1'6"
Reaches mature size in approximately 1 years
Bloom Information
Flowering runs from spring into autumn, with small yellow flowers appearing over a long season whenever conditions are mild. Each flower is short-lived, but the plant blooms more or less continuously. Explosive seed capsules follow quickly and keep the plant spreading.
Detailed Descriptions
Foliage Description
Green to bronzeGrowing Conditions
Sun Requirements
Requires 3-10 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
Care & Maintenance
Care Guide
This plant needs little care and grows readily in sun or part shade on most soils, tolerating drought, poor ground, mowing, and disturbance. In gardens it is usually managed as a weed rather than cultivated, since it spreads aggressively by flung seed and rooting stems. Remove it by lifting the whole plant with its rooting stems before the capsules ripen, as any fragments or shed seed restart the colony. Mulching, hand-weeding, and clearing seed before it sets help limit spread in beds and containers. It tolerates a wide range of conditions from USDA zones 7 through 10 and regrows from the seed bank for years. Container and greenhouse plants are a common route by which it spreads.Pruning
No pruning is needed; management focuses on removing the plant before it seeds. Cut or pull the stems and capsules before they ripen to reduce seeding. Clear fragments fully, as rooting stems regenerate.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons