Fertilising guide

How to fertilise New Zealand Spinach (Spinacia oleracea 'New Zealand')— schedule & NPK

Also called New Zealand Spinach, Warrigal Greens, Kokihi.

More about new zealand spinach

About New Zealand Spinach

Spinacia oleracea 'New Zealand' · also called New Zealand Spinach, Warrigal Greens · edible

A warm-season leafy green that fills the summer gap when true spinach bolts in the heat. Trailing, succulent stems produce small, thick, arrow-shaped leaves with a mild spinach-like flavour. Heat and drought tolerant once established. Harvest shoot tips regularly to encourage bushy, continuous growth throughout summer. Matures in 55–70 days.

Growth habit: Spreading, trailing annual with succulent stems and small, thick, triangular leaves; forms a dense groundcover

What fertiliser new zealand spinach actually wants — and why

New Zealand Spinach feeds in two distinct phases — balanced to build the plant, then high-potassium the moment flowering starts to set and fill a heavy crop.

For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for new zealand spinach: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.

How often to feed new zealand spinach, and which months

Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For new zealand spinach:

The dormant-season rule matters more than the exact interval: skip feeding entirely when new zealand spinach is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.

What strength to mix for new zealand spinach

Follow the crop-feed label rate for new zealand spinach — these are calibrated for hungry vegetables. Consistency through fruiting matters more than strength; erratic feeding causes problems like blossom-end rot.

Feeding always goes onto already-damp soil, never dry roots — water new zealand spinach first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the new zealand spinach watering schedule.

Signs you are over-feeding new zealand spinach

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for new zealand spinach:

Vigorous dark-green leafy growth but few flowers or fruit (excess nitrogen).
Lush foliage hiding the crop; soft growth prone to pests and disease.
Salt crust on the soil and scorched leaf edges in containers.

Signs you are under-feeding new zealand spinach

Pale, yellowing lower leaves and stunted growth.
Small fruit, poor set, and a quickly exhausted plant.
Blossom-end rot and weak cropping from erratic or insufficient feeding.

If the symptoms point at watering, light or roots rather than nutrition, the full new zealand spinach care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

In containers, fertiliser salts build up fast — water new zealand spinach thoroughly so excess drains from the base each time, and flush pots with plain water every few weeks to prevent a damaging salt build-up.

Organic vs synthetic feeds for new zealand spinach

Organic options

Garden compost or well-rotted manure dug in before planting, plus a liquid comfrey or seaweed feed once fruiting starts. UK: comfrey feed or organic Tomorite; US: Espoma Tomato-tone or Neptune's Harvest. Builds soil and feeds in one.

Synthetic / liquid feeds

A balanced feed at planting then a high-potash tomato feed in fruiting — UK: Growmore at planting then Tomorite (Levington) or Phostrogen; US: a balanced 10-10-10 then Miracle-Gro Tomato or a bloom booster.

Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.

Fertilising new zealand spinach — frequently asked questions

What fertiliser does new zealand spinach need?

Balanced (even N-P-K) at planting for roots and frame, then switch to a high-potassium ("high-potash") tomato-style feed once the first flowers open — potassium is what sizes and ripens fruit, not nitrogen. New Zealand Spinach feeds in two distinct phases — balanced to build the plant, then high-potassium the moment flowering starts to set and fill a heavy crop.

How often should I feed new zealand spinach?

Apply a balanced general fertiliser at planting. Light liquid feeds every 4 weeks maintain steady growth. Over-fertilising with nitrogen produces lush but weak growth; moderate feeding is sufficient given the plant's naturally vigorous habit. Apply a balanced general fertiliser at planting. Light liquid feeds every 4 weeks maintain steady growth. Over-fertilising with nitrogen produces lush but weak growth; moderate feeding is sufficient given the plant's naturally vigorous habit. So: a balanced feed or compost at planting, then a high-potash liquid every 1-2 weeks from first flower through harvest across the main season (spring through early autumn).

What strength of feed for new zealand spinach?

What does over-feeding new zealand spinach look like?

Vigorous dark-green leafy growth but few flowers or fruit (excess nitrogen). Lush foliage hiding the crop; soft growth prone to pests and disease. Salt crust on the soil and scorched leaf edges in containers. Staying on a high-nitrogen feed once new zealand spinach starts flowering is the classic error — you get a huge leafy plant and a disappointing crop. Switch to high-potash the moment flowers appear.

Should I flush the soil of new zealand spinach?