New Zealand spinach: sowing, harvesting & preparation
New Zealand spinach is a great alternative to regular spinach, which is hard to grow in summer because it flowers so quickly.
While they are similar in name, taste and leaf shape, New Zealand spinach (Tetragonia tetragonoides) and common garden spinach (Spinacia oleracea) are not related. Nonetheless, you can use New Zealand spinach just like regular spinach when cooking. This means that even in summer, you can have a steady source of fresh leafy greens straight from your own garden. Discover everything about growing New Zealand spinach, from sowing and plant care to harvesting and preparing New Zealand spinach.
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New Zealand spinach: origin and description
New Zealand spinach, also known as Warrigal greens, is native to the coastal regions of New Zealand and Australia, including Tasmania. Sir Joseph Banks brought it back to England after his expedition to New Zealand and Australia with Captain James Cook in the 18th century. It quickly spread to gardens all around Europe.
After a bit of a slow start, New Zealand spinach will rapidly grow into a bushy, herbaceous plant up to 50cm tall. Shoots can spread up 1m along the ground. They are densely branched and very leafy. As a result, you can use New Zealand spinach as an edible ground cover and living mulch in your vegetable garden.
New Zealand spinach leaves are stalked, triangular, fairly thick, dark green and 3 to 12cm long. The leaves taste like regular spinach but more intense.
Small yellow flowers start forming in the leaf axils in August and later develop into the characteristic four-pointed fruit. The fruit contains the seeds and gives New Zealand spinach its scientific name of Tetragonia, which is derived from Greek and means having four angles.
Is New Zealand spinach perennial? In general, New Zealand spinach is an annual to short-lived perennial. New Zealand spinach is not perennial in the UK because it dies at temperatures around 0 °C, though its seeds can survive winter and germinate the following year.
New Zealand spinach: location and sowing
Plant New Zealand spinach in a sunny place with loose, warm, humus-rich soil that retains water well. It is a good idea to enrich your garden bed with some compost to support New Zealand spinach. Work an enriched compost like our Plantura Organic Enriched Compost into the soil before planting. Its high humus content helps retain water in the soil and keeps the soil temperature balanced. On top of that, it is peat-free and environmentally friendly.
- Perfect for all crops and ornamental plants with a high nutrient requirement & for raised beds
- Improves soil quality & promotes healthy root growth
- Peat-free & organic soil: CO2-saving composition
As New Zealand Spinach seeds take a long time to germinate outdoors and young plants are sensitive to cold temperatures, it is best to start the seeds indoors. Start the seeds indoors in small pots from mid-February.
- Soak the seeds in lukewarm water for about 24 hours.
- Fill 8 – 10cm pots with low-nutrient, slightly moistened soil, such as our Plantura Organic Herb & Seeding Compost.
- Sow 2 – 3 seeds around 1cm deep in each pot into the soil and gently water again.
- Place the pots in a bright place, where it is at least 20 °C. It may take 3 – 6 weeks for the seeds to germinate. Do not let soil dry out during this time.
- After germination, leave the seedlings in a very bright place. If several seeds have germinated in one pot, only keep the strongest seedling and remove the rest.
- Feed the New Zealand spinach seedlings every 2 – 3 weeks. Simply add some liquid food like our Plantura Liquid Tomato Food to your watering can.
- After the last frosts in mid-May, harden off the seedlings by placing them outside in the sun for a few hours on sunny days. Then, transplant the New Zealand spinach seedlings into the bed.
How to plant New Zealand spinach seedlings in the bed:
- Pull out any weeds, loosen the soil and mix in some compost like our Plantura Organic Enriched Compost to prepare the bed
- Space the New Zealand spinach plants at least 50x50cm apart
- Water well after planting
How to grow New Zealand spinach in a container
- Choose a container with at least 5L volume and a drainage hole at the bottom
- Fill with humus-rich soil like our Plantura Organic All Purpose Compost
- Lightly moisten soil, place one plant in each container and water well
- Place the container in a warm and sunny spot
Suitable companion plants for New Zealand spinach: Since it belongs to the Aizoaceae family and other members of this family are not typically grown in vegetable gardens, there is no need to pay particular attention to crop rotation or companion planting when growing New Zealand spinach. Suitable companions are different cabbages (Brassica) and tomatoes (Solanum lycopersicum) because New Zealand spinach provides excellent ground cover.
How to care for New Zealand spinach
Weed regularly at the beginning, as young New Zealand spinach grows slowly. Once the crop has established itself, weeds no longer pose a threat.
While it does tolerate drought, New Zealand spinach grows much better and produces higher yields when you water it well. Make sure your plant gets enough water during hot, dry summers.
Just like common garden spinach, New Zealand spinach is a medium feeder. This means that it usually grows well enough without adding fertiliser, as the garden soil already supplies sufficient nutrients. If you want to boost your plant’s growth, add compost to the soil before planting and apply a granulated slow-release fertiliser like our Plantura Tomato Food. Our fertiliser is 100% animal-free and contains a lot of organic matter, promoting healthy soil life.
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Pinch out the shoot tips of young plants to encourage New Zealand spinach to grow dense branches and leaves. Generally, New Zealand spinach is disease and pest free. Occasionally, aphids will inhabit it, but they are typically harmless, though they can be a nuisance when washing the leaves.
Is New Zealand spinach hardy?
New Zealand spinach is not hardy, perishing at temperatures around 0 °C. It is a therophyte, which is a plant that dies after producing seeds and only survives through them. This is why you cannot overwinter New Zealand spinach here. Instead, the plants self-seed. With a bit of luck, the seeds will germinate in the same place again next year. But because they often germinate late, the harvest season also moves back. For an earlier harvest, collect the New Zealand spinach seeds in autumn and start them indoors from February onwards.
How to propagate New Zealand spinach
Propagating New Zealand spinach by seed is easy. As it is mainly self-fertile, there tend to be no unexpected surprises when it reproduces. Harvest the seeds in autumn, as soon as they turn brown and are easy to pick. Let them dry and store them in a cool, dry and dark place until you sow them in March as described above. The seeds remain viable for about 3 years.
How to harvest and prepare New Zealand spinach
If you start your seeds indoors, you can start harvesting New Zealand spinach around July. Pick and prepare leaves and shoot tips every 1 to 2 weeks until autumn. If you do not harvest New Zealand spinach frequently, they will not branch out well, fewer leaves will form, and the plants will go to seed sooner. To harvest New Zealand spinach properly, pinch off individual leaves or stems that are no longer than 10cm with your fingers or use a clean knife. Make sure to leave enough stems and leaves on the plant so that it continues to produce new ones.
Like with all leafy vegetables, you should eat New Zealand spinach quickly after harvesting it. You can store it for a few days in humid conditions at 0 to 2 °C. Wrap the New Zealand spinach in a damp cloth and put it in the refrigerator.
You can prepare New Zealand spinach in the same way as regular spinach and easily substitute it for regular spinach in recipes. Why not use New Zealand spinach in your salads or for fillings and quiches? You can also freeze New Zealand spinach without issue.
Can you eat New Zealand spinach raw? You can, in moderation. Raw it retains many of its nutrients, such as vitamin C. But because raw New Zealand spinach contains higher levels of oxalic acid than cooked, make sure not to eat too many raw leaves.
Is New Zealand spinach poisonous?
New Zealand spinach contains oxalic acid and can have high nitrate levels, like most leafy greens. Generally, plants that get more light will have a lower nitrate content. If you grow New Zealand spinach in a sunny location in summer, nitrate does not usually become an issue.
The oxalic acid levels in New Zealand spinach are also harmless for most people, as long as you consume it in moderation. Blanch the New Zealand spinach and combine it with calcium-rich foods to decrease the amount of oxalic acid. For example, serve New Zealand spinach in a creamy sauce.
Good King Henry (Chenopodium bonus-henricus) is an all but forgotten spinach plant that is even related to common garden spinach, and unlike New Zealand spinach, it is perennial.
