The Oxalis genus includes the False Shamrock and Wood Sorrel.
Oxalis stricta - Yellow wood sorrel by Gmayfield10.
They range in height from 5 to 30 cm (2 to 12 inches). This makes them ideal for growing in rock gardens, or close to the edges of crazy paving.
Oxalis acetosella - Common Wood-sorrel by Jörg Hempel.
Oxalis may flower towards the end of spring, or in the summer (species dependent). When in bloom they carry cup shaped pink or white flowers.
Oxalis triangularis (False shamrock), photograph by Maja Dumat; CC.
Oxalis corniculata (Creeping Woodsorrel / Pprocumbent Yellow Sorrel / Sleeping Beauty), picture by Andreas Rockstein; CC.
Common Names: Wood Sorrel, False Shamrock, Yellow Sorrel, Pink Sorrel, Sourgrass, Sauer klee, Culli, Shamrock, Good Luck Plant, Pickle Plant, Lemon Clover.
Scientific Names: Oxalis adenophylla; O. enneaphylla; O. lacinata; O. grandis; O. Regnellii.
Life Cycle: Hardy bulb. Hardy perennial. Half hardy perennial commonly grown as a half hardy annual by gardeners.
Height: 2 to 16 inches (5 to 40 cm).
Native: Americas, Europe, Asia, Australasia, Africa.
Growing Region: Zones 3 to 10. As a perennial in zones 6 to 10.
False Shamrock, Wood Sorrel, and other Oxalis members can be grown from either roots or seeds.
If growing from roots, then bury the tubers about 4 to 5 cm (~2 inches) deep in the autumn.
The seeds should be sown using fresh seed; these are normally produced at the end of summer. Seeds of Oxalis should be lightly covered once sown.
Plants like to grow in sunny areas of the garden, and have a preference for an acidic soil (pH 4 to 7) that has good drainage.
If first growing Oxalis indoors, then the seeds will take about two to eight weeks to germinate at 12 to 21 degrees centigrade (55 - 70°F).
The young seedlings should be transplanted into the garden at about 10 cm (4 inches; small species) to 40 cm (16 inches; large varieties) apart in mid-spring, well after the last chance of a frost.
If you require more Oxalis plants, then they can be propagated by dividing the tubers in the autumn.
They pretty much look after themselves and require no special attention when growing in the garden. They thrive in dry soils, so only water plants in exceedingly dry conditions.