Black Prince Tomatoes — An Early Siberian Dark Heirloom
Black Prince is the dark heirloom built for short, cool seasons — a Siberian variety that ripens in just 70 days from transplant, earlier than almost any other dark tomato. The fruit is mid-size, 5–6cm (2–2.5 in) across, with deep mahogany-brown skin and the rich, smoky interior that defines the dark tomato family. Where Black Krim or Cherokee Purple can struggle to colour up in a short or cool summer, Black Prince comes through reliably.
The plants are vigorous and genuinely productive, setting fruit heavily and continuing right through the season rather than looking good in a catalogue and yielding little. The flavour is complex and satisfying — sweet and juicy with that characteristic smoky richness — and the dense flesh eats well both fresh and cooked. The mid-size fruit is also the right size for everyday use: a slice fits a sandwich cleanly, with none of the overhang of a big beefsteak.
🇺🇸 US: An annual across the country and a real asset in northern states — the Upper Midwest, Northern Plains, Mountain West, and Northeast — where the short season is a bonus rather than a limit.
Best for: short-season gardens, everyday fresh eating, sandwiches, quick sauces, and mixed heirloom tasting plates.
🌱 How to Grow Black Prince Tomato Seeds
Start Black Prince seeds indoors 6–8 weeks before your last frost, sowing 6mm (¼ in) deep at 21–27°C (70–80°F); seedlings emerge in 5–10 days. Grow them under 14–16 hours of bright light to keep the stems compact, and pot up once the first true leaves appear. Bury the stem deeply at transplant so roots form along it, and set plants out once nights stay above 10°C (50°F).
Space plants 60cm (24 in) apart in full sun, and stake or cage them at planting — despite the moderate fruit size, this indeterminate produces so heavily that the branches droop without support. Water deeply and evenly and mulch to steady soil moisture, and mix bone meal or crushed eggshells into the planting hole for the calcium that prevents blossom end rot. Colour is heat-dependent, so in a cool summer the fruit ripens a dark red-brown rather than full mahogany — the flavour stays excellent regardless.
🍅 Harvesting & Preserving Black Prince Tomatoes
Black Prince tomatoes are ripe when the fruit gives gently at the blossom end and carries a deep, rich fragrance — judge by feel and smell rather than colour, since dark tomatoes ripen to a range of brown-red hues. The skin deepens toward mahogany-brown at peak, but colour consistency isn’t a reliable ripeness signal. Pick regularly; the plant keeps producing steadily once it starts.
Black Prince eats well fresh and holds up in the kitchen, with dense flesh that stores a few days at room temperature out of direct sun — never refrigerate. When the harvest runs ahead, the smoky richness makes an excellent quick sauce: sautéed whole in a hot pan until they burst, the mid-size fruits collapse into a deeply flavoured, dark-coloured sauce unlike anything from a red tomato. Halved and slow-roasted, the smoky notes deepen further.
🍽️ Cooking with Black Prince Tomatoes
Black Prince tomatoes are a true dual-purpose variety — excellent fresh and equally good cooked. Sliced onto a sandwich or into a salad, the mid-size fruit gives you rich, smoky flavour in a size that fits without overhang. On a mixed heirloom plate, the mahogany fruit adds dark colour and depth against brighter red and yellow varieties.
Cooked, this variety shines. Black Prince halved and roasted with olive oil and garlic caramelizes into concentrated, smoky sweetness, and sautéed until it bursts it makes a fast, dark, deeply flavoured pan sauce for pasta. Because the flesh is dense and richly flavoured, it holds its character through cooking better than a watery slicing tomato.
🫙 Saving Black Prince Tomato Seeds
Saving Black Prince seeds is straightforward because the variety is open-pollinated and grows true to type. Scoop the seeds and gel from a fully ripe fruit into a jar with a splash of water and ferment at room temperature for 2–3 days, until a film of mould forms and breaks down the coating around each seed. Pour off the mould and any floating seeds, rinse the good seeds that sank, and dry them on a plate or coffee filter for 1–2 weeks before storing.
As an open-pollinated heirloom, Black Prince is not a hybrid, so its seed comes true — but tomatoes can occasionally cross-pollinate when insects move between nearby varieties. For pure seed, separate different tomato varieties by about 3m (10 ft) and save from your best-flavoured, most typical fruit. Stored cool, dark, and dry, tomato seeds stay viable for 4–6 years, and a quick paper-towel test on a few seeds each spring confirms the batch.
