New Zealand Spinach

Soak seed in water for 24 hours before planting, then sow half an inch deep in loose, fertile soil about 2 inches apart, in rows 3 feet apart. Do not sow outdoors until the danger of frost has passed. Expect uneven emergence over 2 to 3 weeks, so sow thicker than feels necessary and do not give up on the bed early. What gardeners call a seed is a hard, corky dried fruit, and that woody coat is what makes germination slow and ragged. Soaking softens it so water can reach the embryo. The plant itself is frost tender and will not grow in cold soil, so sowing early buys nothing.

Start seed indoors 3 to 4 weeks before your last frost date, soaking it first exactly as you would for direct sowing. Move seedlings to the garden once they are 1 to 2 inches tall and the frost danger has passed. Germination takes 2 to 3 weeks and is uneven, so starting indoors converts that slow, unreliable stretch into a head start instead of a gap in the bed. Since the crop is 50 to 70 days from seed to harvest, those weeks are the difference between cutting in early summer and cutting in midsummer.

Mulch the bed after planting. Black plastic raises soil temperature for an earlier start, while grass clippings or shredded newspaper work well as organic alternatives. This is a heat-loving crop that will not move in cold ground, so warming the soil pays off directly in earlier growth. Through summer the same mulch suppresses weeds and conserves moisture, which keeps the leaves tender rather than tough.

Once the seedlings are established, thin them to stand 12 inches apart within the row. Keep the rows about 3 feet apart, or 2 to 3 feet at minimum. Each plant is highly branched and reaches 1 to 2 feet tall while sprawling 2 to 3 feet across, so seedlings sown at 2 inches will smother each other by midsummer. Thinning early gives every plant the room it needs to keep rebranching after each cut, which is where the whole harvest comes from.

Water consistently through the heat of summer. The plant will survive on far less, but do not read that tolerance as permission to leave it dry. Drought tolerance here means the plant lives, not that it stays good to eat. Consistent moisture is what keeps the shoot tips tender and mild, and a plant coasting through dry spells gives tougher, stronger flavored leaves.

Fertilize monthly through the growing season, applying about a quarter cup of a nitrogen fertilizer such as 21-0-0 per 10 feet of row. Work amendments into the top 6 inches at planting, using no more than 1 inch of well composted organic matter per 100 square feet. Frequent nitrogen keeps the plant producing the soft new shoots you actually eat and holds off early flowering. This is the single rule that most changes what you get, because the harvest is tender growing tips and a plant pushed toward flowering stops making them.

Walk the planting occasionally and look for small holes chewed in the leaves by beetles. Control is rarely necessary. Do not carry over a spray program from regular spinach, and note that leaf miners, the usual reason spinach growers reach for a spray, do not trouble this crop. New Zealand spinach has very good disease and insect resistance and is grown specifically as the leaf miner resistant alternative to true spinach, which is in a different plant family entirely. Cosmetic beetle holes on a plant you harvest by the tip are not worth a pesticide.

Once plants reach 1 to 2 feet tall, cut the top 2 to 3 inches off the shoots, taking the tender tips and leaves. Cut back to about 4 inches when harvesting hard. Harvest frequently and keep picking young tips and shoots as you need them, right up until the first freeze in fall. New growth breaks from the nodes just below each cut, so harvesting is the pruning. Cut often and the plant rebranches into more tips than you started with. Stop cutting and it runs to flower and coarsens. It is a tender vegetable and will be killed by freezing, so the first hard freeze ends the crop.