If you’re looking for a new winter squash to add to your rotation this year (or next) - look no further than the Black Futsu Squash. This interesting Japanese heirloom is in the pumpkin family and has been grown for hundreds of years in its native country. And while you’ll sometimes see it described as producing an “ornamental” or “decorative” fruit, these squashes are actually a superbly delicious addition to any food garden.
As far as growing Black Futsu goes, it’s hardy, relatively pest resistant and shares many commonalities with the winter squashes you’re already familiar with. So inject a little beneficial variety into your garden with the underrated gem that is the Black Futsu Squash!
Starting Black Futsu Squash Seeds
Black Futsu Squash seedlings outgrow standard seed tray cells very quickly, so we recommend planting directly in the ground after the last frost has passed. If your growing season is too short to make that work, they will also do fine starting in a tray or in paper cups (we’ve tried both). Just be careful to move them before the seedling becomes root bound.
In either case, plant two seeds for every mature plant you want to ensure at least one germinates. Black futsu squash germinates easily however, so expect to thin half your seedlings - leaving only the most vigorous to grow out.
Similar to a pumpkin seed, plant black futsu squash seeds at a depth of .5” - 1” in. and keep their soil moist.
Plant Black Futsu Squash
Black Futsu Squash are members of the cucurbitaceae family and as such grow into large, vining plants with deep root systems. They will be more productive grown into the ground or in a large raised bed, but can absolutely be successfully planted into a large container like a grow bag as well.
Traditional spacing calls for six feet between planting rows and 2-3’ ft. between plants in a row. With diligent pruning or trellising (or both), you can push the spacing closer.
These vining plants take to a trellis naturally, so consider training them to grow vertically to save space and improve air flow. The fruits they set aren’t massive, but you’ll still want a sturdy structure like a cattle panel fence.
Plant Black Futsu Squash in a full sun location if possible, but it’s still worth growing them in a partial shade area if that’s all you have. They’ll grow smaller and slower but that’s better than a bare patch of dirt!
As with most garden favorites, Black Futsu prefers well-draining soil rich in organic materials. But don’t let imperfect soil scare you off - ours are currently thriving on poorly draining, clay soil amended with plenty of compost and a very thick layer of wood chip mulch. We recommend applying 1-2 inches of compost to the planting area and regular side dressing with compost after that to feed these hungry plants.
Watering Black Futsu Squash (Pumpkin)
We’ve noticed that our Black Futsu Squash is a little thirstier than the other winter squashes in the same patch, particularly in the first few weeks after transplanting. In very warm weather, you may need to water daily.
Our untrellised Black Futsu plants also grow more closely to the soil than we expected. While we haven’t had any issues with mildew so far, we still do recommend a gentle watering style that keeps the leaves from getting too moist.
Elevate Fruits Off the Ground
If you are not training your plants to grow vertically up a trellis, it’s best to elevate the fruit off the ground to prevent rotting and discoloration. You can do this by placing the young squashes onto a piece of ceramic, a large brick, or even an old broken plate.
Prune Black Futsu Squash
To help your plants produce larger squashes, prune off all but two-three fruits from your Black Futsu so that it can focus its energy on a smaller number.
Pollinate Black Futsu Squash
If you’ve grown other winter squashes like butternut and Jack-O-Lantern pumpkins, you probably remember they have both male and female flowers. To pollinate and set fruit, Black Futsu Squash will need both to be present at the same time.
Female flowers can be identified by what looks like a miniature squash below the flower on the stem. The female’s stems are also noticeably thicker. The male flowers are the thinner stems with no fruit.
For consistent pollination, gather pollen from the male flowers with a q-tip and very gently transfer it onto the internal pistil of the female flower. You can also simply remove the male flower from its stem, peel off the petals and use it directly on the female.
Harvest Black Futsu Squash
At 110 Days to maturity, this is not a particularly fast growing crop!
Harvest your Black Futsu Squash before the first frost when the fruits are heavily ribbed and have lost all green and have transitioned completely to a grey or even orange color. If storing extras, cure them in a warm, dry spot for 2-3 weeks first.
Expect individual squashes to weigh between 3-8 lbs. depending on conditions and how many fruits you allow the plant to set.
Cooking Black Futsu Squash
Like it’s more popular cousin, the Japanese Kabocha squash, Black Futsu are an absolute revelation roasted, made into tempura, or blended into a soup. Our suggestion? Try all three!