How to grow Kiwano

Cucumis metuliferus · horned melon, African horned cucumber, spiked melon

Kiwano (Cucumis metuliferus) — a climbing annual from the semi-arid regions of southern and central Africa, related to cucumber and melon. Its spiny fruit turns yellow-orange when ripe and has green, juicy, jelly-like flesh. Frost kills it and it needs real heat, so in cool climates it is raised from transplants and grown against a warm wall, in a greenhouse or in a large pot.

Checked against sources: October 3, 2026

Quick facts

Type	Vegetable
Family	Cucurbitaceae
Light	Full sun
Soil pH	6–7.5
Frost	does not tolerate frost
Soil for sowing	from 15 °C
Germination	7 days
Seedlings ready	25 days
Sowing to harvest	90 days
Where it grows	Greenhouse, Open ground, At home

When to plant

Sow for seedlings about 5 weeks before planting out.

Plant out in open ground about a week after your last spring frost, once the soil is warm.

In an unheated greenhouse everything moves about three weeks earlier.

The first harvest comes about 90 days after the shoots appear.

Frost dates · When to plant

Care

Greenhouse

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	20…24 °C	balanced (NPK), 7 days into the stage
Growth	every 3 days	—	balanced (NPK), at the start of the stage; balanced (NPK), 7 days into the stage; balanced (NPK), 14 days into the stage
Flowering	every 2 days	21…35 °C	potassium, at the start of the stage; potassium, 7 days into the stage; potassium, 14 days into the stage
Fruiting	every 2 days	21…35 °C	potassium, at the start of the stage; potassium, 7 days into the stage; potassium, 14 days into the stage; potassium, 21 days into the stage
Harvest	every 3 days	—	—

Open ground

Stage	Watering	Temperature	Feeding
Growth	every 4 days	—	balanced (NPK), at the start of the stage; balanced (NPK), 7 days into the stage; balanced (NPK), 14 days into the stage
Flowering	every 3 days	21…35 °C	potassium, at the start of the stage; potassium, 7 days into the stage; potassium, 14 days into the stage
Fruiting	every 2 days	21…35 °C	potassium, at the start of the stage; potassium, 7 days into the stage; potassium, 14 days into the stage; potassium, 21 days into the stage
Harvest	every 3 days	—	—

At home

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	20…24 °C	balanced (NPK), 7 days into the stage
Growth	every 2 days	—	balanced (NPK), at the start of the stage; balanced (NPK), 7 days into the stage; balanced (NPK), 14 days into the stage
Flowering	every 1 days	21…35 °C	potassium, at the start of the stage; potassium, 7 days into the stage; potassium, 14 days into the stage
Fruiting	every 1 days	21…35 °C	potassium, at the start of the stage; potassium, 7 days into the stage; potassium, 14 days into the stage; potassium, 21 days into the stage
Harvest	every 2 days	—	—

Growing notes

Light

Full sun — at least 6–8 hours of direct light a day — in a warm, sheltered spot.

Soil

Loose, rich, well-drained soil kept evenly moist; it does not tolerate waterlogging. pH 6.0–7.5. Raised rows drain better and warm up faster.

Care

About a month before planting out, sow 2–3 seeds 1–2 cm deep in a 10 cm pot. They sprout in 3–8 days at 20–35 °C, only slowly at 12 °C and not at all at 8 °C. Keep the strongest seedling and grow it on at 20–24 °C. Plant out once the air stays above 15 °C, 50–60 cm apart, and give the vines a trellis; flowers need 21–35 °C. Water regularly at the base without wetting the leaves — in hot weather even daily — and feed about once a week, as kiwano is a heavy feeder. In a pot, use at least 20 litres of soil. Fruits reach full size about 5 weeks after pollination and ripen fully about 2 weeks later. Pick them, wearing gloves, as they begin to turn yellow and let them finish ripening at room temperature. Store at 20–24 °C, not in the fridge — cold damages the fruit. Do not eat bitter fruit, and do not eat sprouting seeds.

Pests and diseases of Kiwano

Downy Mildew

Sources

Figures checked against these sources.