Black Futsu is a Japanese heirloom winter squash that transforms as it cures, arriving dark and moody on the vine before softening to a rich chestnut color in storage. The fruit sits squat and heavily ribbed, with the smooth, dense flesh that cooks into something genuinely special: sweet, nutty, with that subtle chestnut note that separates the best squashes from the ordinary. At 105 days to maturity, it's a solid mid-season choice that produces abundantly on compact vines. Grow it in full sun with plenty of room to sprawl, and you'll harvest small, manageable fruits that store exceptionally well through winter.
Full Sun
Moderate
3-11
?in H x ?in W
—
Moderate
Hover over chart points for details
The color shift alone makes this squash memorable: dark black skin ripens to a warm chestnut hue as it sits in storage, signaling perfect sweetness developing inside. The flesh stays remarkably smooth and fine-grained, never grainy or stringy. On productive vines that won't take over your entire garden, each plant yields multiple small fruits perfectly sized for a household meal. This isn't just a storage squash; it's one that actually improves with time, developing deeper flavor and better texture week after week in a cool corner of your kitchen.
Black Futsu shines in the kitchen as a roasted squash, where its sweet chestnut flavor develops fully and the smooth texture breaks down into a silky puree. It works beautifully in soups, especially Asian-inspired preparations with ginger and miso, where its subtle sweetness complements savory broths without overwhelming them. The smaller size makes it approachable for baking or braising whole, and the dense flesh holds up well to longer cooking times without becoming mushy. Store it and you can enjoy it through winter in any preparation where you want squash that tastes like something rather than nothing.
No timeline data available yet for this variety.
You can start seeds indoors in warm conditions 3 to 4 weeks before your last frost date, keeping soil temperature around 70 to 95 degrees Fahrenheit. Transplants should be hardened off carefully before moving outdoors, as squash seedlings are brittle and sensitive to temperature shock.
Set out transplants after your last frost date, once soil has warmed and there's no danger of cold nights. Space plants 18 to 36 inches apart in full sun, burying them slightly deeper than they grew in their pots to encourage stronger root development.
Direct seed is the most reliable method: wait until soil has warmed to 70 degrees Fahrenheit or higher, then sow seeds 1/2 to 1 inch deep, spacing them 18 to 36 inches apart. Germination happens in 5 to 10 days under warm conditions.
Black Futsu reaches maturity in 105 days from sowing. Harvest when the skin has hardened and resists puncture from a fingernail; the fruit should feel solid and heavy for its size. Pick all squash before the first frost, cutting them from the vine with 2 to 3 inches of stem attached. The black skin is the first indicator of ripeness, though the fruit will continue to mature and develop sweetness in storage as the skin gradually turns to a rich chestnut color over several weeks.
Enter your ZIP code to see a personalized growing calendar for this plant.
“Black Futsu comes directly from Japan, where it has been grown for generations as a reliable producer and exceptional keeper. The heirloom classification speaks to its authenticity: this is the real squash, preserved and passed along by gardeners who valued its practical virtues and honest flavor. It arrived in American seed catalogs through the careful curation of heirloom seed savers who recognized that some older varieties offer something modern breeding had overlooked: genuine taste and the ability to store without losing quality.”