Iron Cross Plant (Oxalis deppei)
At a glance
- Exposure
- Full sun
- Frost limit
- −12.2 °C
Cultivation
An easily grown plant, preferring a sandy soil in a warm dry position. This species is only hardy outdoors in the milder areas of Britain, tolerating temperatures down to about -5°c or perhaps a bit lower if the soil is very well-drained. The bulbs are easily harvested in late autumn, however, and can be stored overwinter in a cool frost free place, replanting them in the spring[K]. In milder winter areas a good mulch is usually sufficient to see the bulbs through the winter and they will then normally be more productive of leaves and flowers in the following year. Plants have survived the winter for several years without a mulch on our trial grounds in Cornwall[K]. A very ornamental plant, flowering freely all summer[1, K]. It was formerly cultivated in Mexico for its edible tuber (this may be a mistaken entry that should have referred to O. tuberosa. Whilst the root of this plant is edible it is neither productive nor very flavourful. The leaves and the flowers are far superior[K]). This species is closely related to and probably part of O. tetraphylla.
Propagation
Seed - best sown as soon as ripe in a cold frame. Prick out the seedlings into individual pots when they are large enough to handle and plant them out in late spring or early summer. Our plants have never produced seed. Division in autumn, harvest the bulbs and replant in the spring. They usually increase very freely.
Edible uses
Leaves and flowers - raw or cooked. A delicious lemony flavour, the leaves are tender and fairly free of fibres even when they get older[K]. Both the leaves and the flowers make a very refreshing and thirst-quenching munch in the garden, they also make an excellent flavouring in salads[K]. The leaves are available from June to October and the flowers from July to October, or even later in mild autumns[K]. Use in moderation, see notes at top of sheet. Root - raw or cooked. The roots are up to 10cm long and 3cm wide at the top, they are tender and juicy but usually insipid[K]. Occasionally the root has a pleasant acid flavour, we have yet to find out what causes the difference[K].
Habitat
Not known
Native range
Southern N. America - Mexico. Occasionally established in Europe.