I first planted New Zealand spinach in one of my raised beds and I’ve never had to replant it since. Little seedlings dependably reappear in my garden every year. I didn’t know much about this healthy leafy green until a friend offered me a few extra seedlings she had growing in her garden. Always keen to try something new, I eagerly planted them in the garden.
Besides salad greens, I love growing a selection of tougher greens I can cook with in my raised beds, from kale and Swiss chard to pak choy—and New Zealand spinach. Read on for tips on growing this yummy spinach that’s not really a spinach (I’ll explain below) from seed.
So what is New Zealand spinach?
While it might pass the Popeye test in terms of nutrition, New Zealand spinach (Tetragonia tetragonioides) isn’t actually part of the spinach family. However I do use the tender young leaves as a spinach substitute. They have a pretty similar mild flavour. Like spinach, it’s recommended that you cook the leaves to remove the oxalates. The plant originates in New Zealand, Australia, and Asia and is considered a perennial in those warmer climates. Here in North America, it’s grown as more of a tender annual, but depending on your zone, it could overwinter. Unlike spinach, which is more of a cool weather veggie, New Zealand spinach thrives in the heat.
New Zealand spinach is considered to be an heirloom vegetable. Apparently Captain Cook and his crew ate it to prevent scurvy in the 1700s. The plant grows along both the shorelines of Australia and further inland in woodland settings. Because of these voyages, it was the first Australian vegetable to be cultivated in England—botanist Sir Joseph Banks brought seeds back with him. Some will argue it’s actually better than spinach.
Sowing New Zealand spinach from seed indoors
If you’d like to give seeds a head start indoors under your grow light system, plant them about three to four weeks before the last frost date. New Zealand spinach seeds remind me a bit of beet seeds in their size and shape. Soaking them before planting for 24 hours in water that’s at room temperature will help with germination.
Sow seeds in a seed starting mix about a half an inch (about 1 cm) deep. Keep the soil moist (I use a mister to avoid disturbing the soil) until the seeds have germinated and seedlings start to grow. (Plants take about 55 to 60 days to mature.)
Direct-sowing seeds in the garden
Because New Zealand spinach is a heat lover, temperatures need to be pretty warm before you can direct-sow seeds outside. Sow them in May or June, once temperatures are consistently above 50° F (10° C). Choose a spot in your garden bed where plants will have a bit of space to spread. If you want your plants to reseed and come back every year, plant your seeds or seedlings in a space where they won’t interfere with other plants once they start to grow.
Make sure your garden gets at least eight to 10 hours of sun in a day. You’ll want to plant seeds or seedlings in nutrient-rich soil that drains well (don’t forget these are drought-tolerant plants!). It’s okay if soil is a bit sandy. You may want to generously amend the soil before sowing seeds or planting seedlings. Partway through the season, side-dress your rows with compost.
Sow seeds (after completing the soaking method mentioned above) about three to four inches (7.5 to 10 cm) apart in rows that are about 12 inches (30.5 cm) apart. To give the plants space to grow, you may want to thin them further to about 10 to 12 inches (25 to 30.5 cm) apart. Don’t let those young plants go to waste. Bring them inside to steam or add to a stir fry. If you find some seeds haven’t germinated, plant extra seeds in the spaces that have been left bare.
Caring for plants throughout the summer
Though New Zealand spinach is a heat lover and accustomed to a hot and humid climate, you might find the leaves will taste less bitter if they get a little bit of shade sometime throughout the day. Watering plants regularly will help leaves to maintain their flavour, too.
New Zealand spinach plants are pretty unbothered by pests and diseases. Fertilizing plants regularly and generously with a 10-10-10 formulation will prevent plants from going to seed too early in the season.
Plants can reach about a foot tall and sprawl outwards, as well. The latter kind of reminds me of purslane plants in that respect.
Plants will tolerate a very light frost—I’ve harvested right through the fall—but a hard frost will do the plants in. My garden is also in a bit of a protected spot, so they might not tolerate frost in a more exposed garden.
Harvesting New Zealand spinach
Like other greens, New Zealand spinach is highly nutritious. I have used it in stir fries, steamed over rice, stuffed in squash as a spanakopita filling, and to add some healthy veggies to a soup broth. When I’ve looked up recipes to use up my New Zealand spinach, I’ve also found it referred to as warrigal greens or Botany Bay greens. Apparently it’s quite a popular green among top chefs.
Using a sharp pair of herb scissors, I will snip young leaves or side shoots off the main stem. Just like herbs, regular trimming encourages plant growth and bushier plants. Prune off the bigger leaves that you might not end up eating.
I have found that when I let plants go to seed in the fall, they’ll reseed the following spring. I have a bit of a New Zealand spinach “patch” on the go where I avoid planting other plants because I know I’ll find seedlings poking through the soil at some point in the spring.