Warrigal greens Tetragonia tetragonioides are an edible Australian native groundcover. This bushfood is a member of the family Aizoaceae and is related to marigolds and figs.  It is also native to New Zealand and countries around the Pacific rim, sometimes referred to as New Zealand spinach or Botany Bay spinach.  Its Australian name comes from the Aboriginal word “warrigal” meaning wild or wild dog and the scientific name reflects its 10-sided seeds.

Growing naturally in all parts of Australia except the Northern Territory, it is a leafy ground cover spreading to around 1.5m.  It can be seen growing between rocks near beaches, on sand dunes and in estuaries and is tolerant of wind and salty soil1.

Its leaves are fleshy and triangular with tiny green-yellow flowers between the leaf base and the stem2.

The particular requirements requirements for growing in gardens seem to be depend on the original source of seeds – if from a sandy area, then it will tolerate more soil with a higher sand content or if from cool to temperate regions it will be more tolerant of cold.

Planting Schedule

This useful vegetable can be grown from both seeds and cuttings.

Warm areas: March – April (seeds in trays), May – June (seedlings)

Temperate areas: March – April (seed in trays), May –  June (seedlings)

Cool to cold areas: January – February (seed in trays), April – May (seedlings)

Seeds will grow directly in the soil if it is not too hot or too cold.  It is best to soak them in warm water overnight before sowing.

It is a perennial in temperate – warm areas, but an annual in cooler zones.

Position, Position, Position

It will grow in full sun or part shade.

Talking Dirty

This plant is fairly adaptable, tolerating pH 5.8-7.5 and a range of soil types from sandy to clay as long as it is moist and free draining.

Invasiveness?

Because it has long trailing stems which root fairly easily and self-seeds it can be quite invasive.  If that is as problem for, then it can be grown in pots with the leafy stems left to trail.  However, its readiness to grow and shallow roots makes it a useful ground cover under fruit trees.  If grown under shrubs it will be quite happy to climb.

However, its enthusiastic spreading habit makes it a good choice to cover problem areas and minimise weed growth.  And at the same time it provide a reliable source of food.

Feed Me!

Mature compost or a little well-rotted manure is all that is needed.

What about the Water?

Keep soil moist as its shallow root system means that it will struggle in dry conditions.

Are we there yet?

These plants are quick growing, so after planting seedlings you will be able to harvest leaves in around 10 weeks.

Pests and the Rest

Although a remarkably disease resistant plant, it can succumb to mosaic virus and some fungal diseases.

Slugs, snails and caterpillars may take an occasional nibble but they don’t seem to be all that keen. Root knot nematode, aphids, two-spotted spider mite have occasionally been observed, but overall it is fairly pest-resistant.

Eat Me!

The leaves make a wonderful spinach substitute, but stems are not edible.  Leaves are high in vitamins A, B1, B2 and C3 and fibre as well as anti-oxidants4. They have a mild taste, but since they contain high levels of oxalic acid, they should be blanched before eating i.e. 1 – 2 minutes in boiling water.

They can be used hot in soups and stir fries or cooled and added to salads.  They benefit from some added acid such as vinegar or lemon juice and are given zing by spicy dressings.

References

  1. Watkins CB, Brown JMA, Dromgoole FI. 1988. Salt tolerance of the coastal plant, Tetragonia trigyna Banks et Sol. Ex Hook. (climbing New Zealand spinach). New Zealand Journal of Botany 26: 153-162
  2. Australian Native Plants Society (Australia)
  3. Samuelson J, Drost D. New Zealand Spinach in the Garden. Utah State University Horticulture Extension.
  4. MA Lee, HJ Choi, JS Kang, YW Choi, Joo, Woo-Hong. 2008. Antioxidant activities of the solvent extracts from Tetragonia tetragonioides. Journal of Life Science 18 (2) 220-227.