The Oxalis genus includes the False Shamrock and Wood Sorrel.
They range in height from 5 cm 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 may flower towards the end of spring or in the summer (species dependent) and they carry cup shaped pink or white flowers.
Oxalis stricta - Yellow wood sorrel by Gmayfield10.
Oxalis acetosella - Common Wood-sorrel by Jörg Hempel.
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.
Flowers: Spring and/or summer.
Flower Details: Yellow, white, pink, red. Cup-shaped. Five petals. Ten stamens.
Foliage: Obovate. Usually three, sometimes four leaflets.
Seed: cover seed. Late Summer and autumn. Spacing 3 to 16 inches (8 to 40 cm).
Root: 2 inches (5cm). Autumn.
Sow Inside: Germination time: two weeks to two months. Temperature 60 to 70°F (16 to 21°C). Late summer and autumn (use fresh seeds). Transplant outdoors a few weeks after the last frost; temperatures should not drop below 41°F (5°C).
Requirements: Full sunlight or light shade. Good drainage. Soil pH 4 to 7. Ordinary soil. In cool areas bring tubers indoors over the winter. Propagate: dividing in the spring or autumn).
Closely Related Species:
Miscellaneous: Invasive in many areas. Seed heads explode and can spread seed as far as 160 inches (400 cm).
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. The 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.