Hourensou: Japanese Spinach
(Spinacia oleracea)

Nutritional Information:

High in vitamins A and C. Rich in riboflavin. Leaves contain oxalic acid (6 - 8% in young leaves, 23 - 27% in the cotyledons). The oxalic acid binds calcium into an insoluble salt (calcium oxalate), which cannot be absorbed by the body. The same applies to the iron, as it is bound, leaving only 2-5% of the seemingly plentiful supply actually available for absorption.
100g raw leaf contains:
690 mg potassium
49 mg calcium
69 mg magnesium
47 mg phosphorus
16 mg sodium
2 mg iron
0.7 mg zinc
0.32 mg manganese
4200 µg beta-carotene (vitamin A)
350 µg retinol
35 mg vitamin C
270 µg vitamin K
210 µg folic acid

How to Enjoy it:

Hourensou can be eaten raw in salads, or cooked by steaming or boiling briefly for 2 to 3 minutes. Alternatively braise it and serve topped with sesame dressing. Water left from cooking will contain iron and other water-soluble nutrients, so do not throw it away!
Hourensou seedling (click for full sized image) Hourensou in autumn (click for full sized image)

Hourensou under frost (click for full sized image)

Hourensou survived winter (click for full sized image)

Produce normally available from May to November.