Bulbs

Oxalis
Oxalis
wood sorrel

- Height 2-12 in (5-30 cm)
- Planting distance 1/2-1 ft (15-30 cm)
- Flowers spring, summer, or fall
- Well-drained, humus-rich soil
- Sun or light shade
- Bulbs available early fall and spring
- Hardy zones 5-9

many members of the wood sorrel genus are invasive weeds, but a few of these hardy low-growing plants make graceful additions to a rock garden or serve as low edging for a border. All have neat clumps of handsome foliage comprised of several leaflets; the funnel-shaped flowers, with five petals, open wide in full sun.

Popular species and cultivars
Oxalis acetosella, often called Irish Shamrock, is a European native. In fact, it is not a true bulbous species but it spreads to 12 in (30 cm) from a creeping rhizome. It has neat tufts of pale green leaves and pearl-white flowers faintly veined with pink. It grows only 2 in (5 cm) high and is suited to a woodland setting where it will naturalize freely. Oxalis adenophylla grows 3-4 in (7.5-10 cm) high from a bulbous rhizome and produces compact rosettes of crinkly gray foliage. The long-stemmed lilac-pink flowers are borne above the leaves from late spring to midsummer. It is hardy to zone 7. Oxalis bowiei grows to a height of 1 ft (30 cm), bearing purple to rose flowers that are 1-11/2 in (2.5-4 cm) across. Although not winter hardy north of zone 8, it may be grown as an annual in the North. Oxalis deppei, known as the good-luck plant, has foliage resembling a four-leaf clover. Growing to a height of 1 ft (30 cm), it bears red or purplish flowers 1/2-1 in (1.3-2.5 cm) wide from July through September. It is hardy to zone 8. 'Alba' is a white cultivar. Oxalis pes-caprae is called the Bermuda buttercup because this South African wildflower has naturalized well on that island. Growing 1 ft (30 cm) high with three notched leaflets as foliage, it bears many yellow flowers in early spring. It is hardy to zone 9. Oxalis violaces, a 10 in (25 cm) tall wildflower hardy to zone 5, thrives in most of the eastern half of the United States, with small rose-purple blooms in late spring.

Bulbs