White wood sorrel, Oxalis crassipes alba, is a garden favorite in the South, flowering from March through September.
White wood sorrel is a low-growing perennial to maybe 12″ or so. Oxalis crassipes alba grows to 18″ wide. Buy a few and tuck here and there amongst other perennials or in an informal group. It’s easy to naturalize and is at home in woodland or nonchalant garden settings. I would consider it an excellent choice for the cottage garden.

White wood sorrel’s small flowers (1/4″ star-shaped) are pure white and cover the clover-like foliage in waves.
Sorrel doesn’t need sopping wet soil, but it will have a longer bloom period in moist soils. Sorrel can handle average water (rainfall only) once established and will do fine in poorer soils.
Poorly drained soil should be avoided. Oxalis crassipes alba can grow in partial shade to full sun.
The white flowers are delicate so full afternoon sun may wash them out. Morning sun with mid-late afternoon shade would be excellent. White wood sorrel grows fine in alkaline, neutral, and acidic soil.

Oxalis crassipes is a casual, undemanding plant, best used in situations that call for informal plantings. White wood sorrel can perhaps best be described as charming and is a good choice for container plantings. It looks like a native woodland plant, yet it is not. It is at home in woodland gardens.
There is a pink version that has rosy-lavender flowers and similar growth requirements and character in the garden.
Plant type: Herbaceous perennial
Height: 12″
Native status: non-native
Bloom period: March-October (with adequate moisture)
Winter hardiness: 5-9
Of note: Easy to grow southern favorite. Spreads around the garden, but not aggressively. Use for naturalizing or in cottage/woodland gardens. Prefers moist soils. Butterflies like.