Red kuri squash, how to grow it from seed to harvest

Red kuri squash

Red kuri squash, also called Orange Hokkaido and Japanese squash, is a delicious vegetable, fleshy and tasty.

Summary of Red Kuri facts

NameCurcubita maxima
Family – Cucurbitaceae: gourd family
Type – vegetable

 – 8 to 16 inches (20 to 40 cm)
Exposure – full sun
Soil – rich and well drained

Sowing red kuri squash: spring  –  Harvest: September, October, November

Easy to grow, they prefer rich soil and sunlit spots.

Sowing and planting red kuri squash

Red kuri seedlingIt is possible to start sowing during the month of March, in a sheltered place, or in mid-May directly in the ground. Red kuri squash is a frost-sensitive plant and you must ensure that the last frosts are past before transplanting them to their growing bed in the vegetable patch.

For areas with milder climates, the first seedlings can be started in the month of April.

  • Red kuri squash loves heat, and requires warm to hot climate to germinate properly.

If sowing in nursery pots in spring, count more or less 3 weeks before transplanting them to the ground. That’s why there is no need to sow early.

In a good soil mix:

  • Lightly press down 2 to 3 seeds per nursery pot.
  • Once seeds have sprouted, keep only the most vigorous one.
  • 3 weeks later, they can be set into their growing bed, provided  the last frost spells have passed.

It is also possible to sow directly in the ground, starting from the month of May.

  • The richer your soil, the more abundant your harvest will be.
  • Feel free to add fertilizer or manure upon planting.
  • Place 2 or 3 seeds in each seed hole, placing them 8 feet (2.5 m) apart on all sides.
  • Thin after 2 to 3 weeks, keeping only the most vigorous seedling.

Pruning and caring for red kuri squash

You must pinch stems off regularly to stimulate plant growth, this will ensure better productivity.

Pinching or pruning red kuri

Young red kuri fruit will grow more if the plant is pinchedMore branches will grow from the base: best keep a single fruit on each branch.

  • When the red kuri squash has 5 leaves per stem, pinch each  stem off just above the second leaf from the center.
  • When these stems have again grown around 10 leaves, pinch each stem off again above the 5th leaf.
  • When a red kuri squash gets about as big as a large apple, pinch off the stem that bears it two leaves after the fruit.

Once the plants have grown well, mulch their base to keep the soil moist and cool.

  • Mulch also keeps the squash from touching the soil thus avoiding the risk of fruit rot (see below). You can use flax mulch, straw, a slab of wood or upside-down crates.

Watering red kuri, fruit rot and diseases

Red kuri squash leaf with diseaseWater regularly in summer and avoid wetting the leaves.

Other diseases include:

Pollinating red kuri and fruit set

Red kuri, like all other squash, has both male and female flowers on the same plant. Male flowers tend to open and appear earlier. Female flowers open up a bit later.

Only female flowers can set fruit. You can tell by checking the base of the flower: if there’s a bulge, it’s a female flower.

Female red kuri flower with bulgePollinators normally do the work well, and most female flower set fruit naturally.

If you want to control pollination (for instance, avoid cross-pollination, or because many flowers dropped already), you can hand pollinate red kuri:

  • Pick a male flower and remove the outer petals.
  • Brush the central stamen (stem with pollen) round and round inside a female flower.

Harvesting red kuri squash

When to harvest red kuri, tipsHarvest the red kuri squash as soon as leaves dry up and skin darkens.
Fruits should start to mature as early as September, but best is to harvest your squash when the stem has dried up and foliage has turned yellow.

  • That is why harvest usually takes place at the beginning of October.
  • They must be harvested before the first frost spells when their color is a deep orange.
  • Keep the stem as long as you can when cutting the red kuri squash off.

After the harvest, red kuri can keep for almost a year, in a dry room with a temperature ranging between 50 to 60°F (10 to 15°C).

  • After the harvest, a good practice is to destroy any remaining leaves and stems which often bear diseases and fungus.

Keeping red kuri seed for sowing

  • Sliced red kuri with seeds for keepingDry the seeds and make sure all flesh is washed away.
  • Let them dry on a cloth or paper towel for about a week. A dry spot is best.
  • Store in a paper envelope (nothing airtight because it might mold) and keep the envelope in a cool, dark spot.
  • Write the year on the envelope: germination is always highest the first year.

Learn more about red kuri squash

Native to North America, red kuri squash usually boasts a brick-red color, but some may turn out yellow.

Red kuri squash from the gardenWith high levels of vitamin A, B, C, D and E and trace elements (phosphorus, calcium, magnesium, potassium, sodium and iron), these fruits also have the advantage of keeping for a long time over winter, ideally at temperatures of about 50 / 55°F (10 / 12°C).

Since it contains 92% water, red kuri squash is low on calories and is potassium-rich, which makes it an excellent vegetable against hypertension. Its flesh has high levels of vitamin A, giving it antioxidant properties.

The different varieties of red kuri squash that are grown most are ‘Red kuri’, ‘Uchiki kuri’, ‘Akaguri’ or the ‘Potimarron français’.

Of course, another reason why the red kuri squash is very appreciated is because its sweet flesh reminds one of chestnut.

Smart tip about red kuri squash

Unlike squash, you don’t need to remove the skin of red kuri squash before cooking.

Try growing red kuri vertically up a wall to maximize space in your vegetable patch!

Images: CC BY 2.0: Maja Dumat, CC BY-NC 2.0: seeingbeauty; iStock: ; Pixabay: Steve Buissinne