Oxalis

Oxalis triangularis

Wood Sorrel

Oxalis triangularis is a tuberous geophyte from subtropical South America, storing water and energy in underground tubers that rot if kept soggy. Give it bright indirect light and let the top inch or two of mix dry out before watering again. It naturally cycles through periods of dormancy, when foliage dies back and watering should be reduced until new growth appears.

Oxalis tetraphylla

Four-Leaved Pink Sorrel

Oxalis tetraphylla is a tuberous geophyte from the seasonal climates of Mexico and Central America, storing water and energy below ground in its tubers. Give bright indirect light and water only when the top inch of mix has dried, letting it approach dryness between drinks, since the tubers rot if kept wet. Expect it to slow or die back to dormancy at times — ease off water entirely while it rests rather than forcing growth.

Oxalis latifolia

Garden Pink-Sorrel

Oxalis latifolia is a tuberous geophyte from a broad range across the Americas, storing water and energy in underground tubers that rot if kept wet. Give it bright, indirect light and a gritty, free-draining mix, watering only when the top inch or two of soil has dried out. The tubers also drive a natural dormancy: if foliage dies back, ease off water and let the plant rest rather than forcing it.

Oxalis oregana

Oregon Wood Sorrel

A rhizomatous woodland geophyte of the Pacific Northwest forest floor, this redwood sorrel is adapted to deep shade, cool air, and the steady moisture of a coniferous understory. Give it bright shade to low, indirect light and keep the mix evenly but lightly moist, watering when the top inch has just begun to dry; the storing rhizome will rot if left sitting wet. It prefers cool temperatures and resents direct sun, which scorches its clover-like leaflets.

Oxalis spiralis

Spiral Sorrel

Oxalis spiralis is a subshrubby wood sorrel from montane regions of South and Central America, where it grows in cool, humid conditions with dappled light. Many Oxalis grow from bulbs or rhizomes that store water and rot if kept soggy, so let the top inch of mix dry before watering and err toward the dry side. Give it bright indirect light and average household humidity; it may slow or die back seasonally, which is normal rather than a sign of trouble.