Last updated:
Black turtle beans are the crop for anyone who wants a store cupboard rather than a glut. They are ordinary bush beans grown to full maturity, which means the work is front-loaded: sow them like any bean, then leave them alone until the pods yellow and rattle. What you get is a year's supply of black beans at a fraction of the shop price.
The catch is the season length. They need around 90 days from sowing to dry pod, against 50 for snap beans, so they suit gardeners with a real summer. Everything else about them is unremarkable — which is exactly what you want in a drying crop.
Quick answer
Sow black turtle beans after the last frost, when the soil is 20–27°C (68–80°F). Push seeds 2.5 cm deep and 15 cm apart, water them in, and expect seedlings in 8–16 days. They are bush plants, so no support is needed. Water weekly at the base, never over the leaves, and leave the pods on the plant until they turn yellow and the beans rattle. Harvest at about 90 days, shell, dry indoors for a few days, and store airtight — they keep up to two years.
| At a glance | Details |
|---|---|
| Botanical name | Phaseolus vulgaris — a black-seeded cultivar of the common bean |
| Family | Fabaceae; fixes nitrogen |
| Habit | Bush, 60–90 cm (2–3 ft); no support needed |
| Flowers | Purple |
| Sun | Full sun |
| Soil | Well-drained, organic-rich, pH 6.0–7.0 |
| Sowing | After last frost, soil 20–27°C |
| Germination | 8–16 days |
| Days to harvest | About 90 for dry beans; 50–60 if picked green |
| Yield | Up to 30 pods per plant, 6–8 seeds per pod |
{getToc} $title={Table of Contents}
What Black Turtle Beans Are
Black turtle bean is a cultivar of the common bean, Phaseolus vulgaris — the same species as the green and yellow snap beans in the next row. The difference is the harvest stage: snap beans are picked as immature pods, black turtle beans are left until the seed inside is fully mature and dry. Botanically nothing changes; agronomically everything does, including the season length.
Plants are bushy, top out around 60–90 cm, and carry purple flowers followed by green pods that dry to a pale straw colour. Each pod holds six to eight small, oval, shiny black seeds. A single plant can carry up to 30 pods, which is why a short row is usually enough.
Where They Came From, and Why They Matter
Black turtle beans originated in Central and South America. Spanish and Portuguese traders carried them to Asia and Africa in the late 1700s; they only became common in North America and Britain much later, largely through Latin American cooking.
Nutritionally they are a serious food: high in protein and fibre, a useful source of iron and folate, and rich in anthocyanins — the pigments responsible for the black skin. That is the honest claim. They are a good food, not a medicine, and much of what gets written about beans and health outruns the evidence.
When to Sow Black Turtle Beans
After the last frost, when the soil has warmed to 20–27°C (68–80°F). This is not a crop to gamble with: seed sown into cold, wet ground rots before it emerges, and you will not know it has failed until nothing appears. A soil thermometer is worth more than a fortnight's head start.
In short-season climates, start them indoors and plant out once the weather has settled — see starting black turtle beans indoors. Handle the roots carefully; beans resent disturbance.
Where to Grow Them
Full sun, well-drained soil, plenty of organic matter and a pH around 6.0–7.0. Work compost or well-rotted manure in before sowing — after that they need no feeding, because the roots fix their own nitrogen.
Watch: Using Composted Chicken Manure
How much rotted manure to work in before sowing, and why it must be well rotted.
Prefer YouTube? Watch it there.
Sowing Black Turtle Beans
Soaking the seed overnight is optional but does shave a day or two off germination. Beyond that, the method is the same as any bush bean. Black turtle bean seed is widely available if you cannot find it locally.
- Wait for warm soil — 20°C or above, after the last frost.
- Sow 2.5 cm (1 in) deep, 15 cm (6 in) apart, in rows 45–60 cm apart.
- Two or three seeds per station, then thin to the strongest. Five or six per hole is wasteful of seed and gives you a clump that competes with itself.
- Water lightly, then keep the surface moist until they are through.
- Expect 8–16 days. The sprouts come up dark purple.
- Mulch once they are up to hold moisture and suppress weeds.
- Succession sow every three weeks until midsummer if you want fresh pods as well as dry beans.
Caring for Black Turtle Beans
Watering
Weekly, at the base, and more generously once flowering starts. Never overhead — wet foliage overnight is how bean rust and mildew get a foothold. The soil should be moist, not saturated.
Feeding
None. The nodules on the roots fix nitrogen, and feeding nitrogen produces leaf at the expense of pods.
Rotation
Grow beans in the same ground no more than one year in three. A three-year rotation keeps soil-borne disease pressure down, and it is the cheapest disease control available.
Watch: Growing Organic Black Beans
The growing season start to finish, in the garden.
Prefer YouTube? Watch it there.
Companion Plants and Rotation
Black turtle beans grow well alongside beetroot, cabbage, carrots, cauliflower, celery, sweetcorn, cucumber, aubergine, marigolds, peas, radishes, rosemary, chamomile and sunflowers. The useful ones are the flowers — marigold and chamomile — because they bring in the hoverflies and parasitic wasps that deal with aphids.
Avoid following other legumes in the same bed, and keep them clear of onions and garlic, which are traditionally thought to suppress bean growth.
Growing Black Turtle Beans in Containers
Because they are short and bushy, black turtle beans work in pots where pole beans would not. A container 30 cm across with about 18 cm of potting mix is enough for two or three plants. The constraint is water: containers dry out fast, and consistent moisture matters most once flowering begins. If they dry out at that stage, they drop their flowers and the crop is over before it started.
Harvesting
For dry beans, leave the pods on the plant until they turn yellow and the seeds rattle inside. That is around 90 days from sowing. Pull or snap the pods off, shell them, and spread the beans on a tray indoors for a few days to finish drying before storing.
If you want to eat them green, treat them exactly like snap beans and pick at 50–60 days while the pods are still tender. You cannot have both from the same plant: once the pods start maturing seed, the plant stops producing new flowers.
Watch: When and How to Harvest Black Beans
Pod colour, the rattle test, and shelling without losing the crop.
Prefer YouTube? Watch it there.
Storing and Using Them
Dry the shelled beans somewhere airy for a week, then store in an airtight jar labelled with variety and date, in a cool dark place. Properly dried, they keep for up to two years — and because black turtle is an open-pollinated variety, you can hold back seed for next year and it will come true.
They cook like any black bean: soups, stews, rice dishes, salads. Dried beans need soaking overnight and a hard boil for ten minutes before a long simmer — the boil matters, particularly with slow cookers, because it destroys the lectins that cause stomach upset.
Black Turtle Bean Seeds I Recomand
Black turtle beans are a fuss-free bush bean — sow them once the soil warms and they crop heavily for drying or fresh eating. Whether you want a small 25-seed start, a soup-ready heirloom, or a bigger 50-seed packet, these are the picks I reach for most often.
A small, no-fuss start of heirloom black turtle beans. Bush habit means no trellis needed, and 25 seeds is plenty to try a row.
Rich-flavored black beans bred for soups and stews. A high-yield warm-season legume from Isla’s Garden Seeds — a nice gift idea too.
A bigger 50-seed packet of heirloom bush beans for a proper harvest. Terrific black beans for drying or picking fresh.
The same reliable heirloom bush bean in a 25-seed packet. Terrific black beans with an easy, compact habit.
Affiliate links above. As an Amazon Associate I earn from qualifying purchases.
Black Turtle Beans: Frequently Asked Questions
How long do black turtle beans take to grow?
About 90 days from sowing to dry pods. If you pick them green as snap beans, 50–60 days.
Do black turtle beans need support?
No. They are bush beans growing 60–90 cm tall and hold themselves up, which makes them easy to fit into gaps.
How many beans does one plant produce?
Up to 30 pods per plant, with six to eight seeds in each pod.
Can I eat them fresh instead of dried?
Yes. Pick the pods young and cook them like snap beans. Just decide early — leaving pods to mature stops the plant flowering.
Can I grow them in containers?
Yes, better than most beans. Use a pot at least 30 cm across with about 18 cm of compost, and keep the water consistent once flowers appear.
Why did my seeds not come up?
Almost always cold or wet soil. Below 20°C the seed rots rather than germinates. Wait for warmer ground, or raise plants indoors.
Do they need fertilizer?
No. They fix their own nitrogen; compost at planting is the only feed needed.
How long do dried black turtle beans keep?
Up to two years in an airtight container in a cool, dark, dry place.
Can I save seed from them?
Yes. It is an open-pollinated variety, so saved seed comes true. Choose your healthiest plants and let those pods dry fully on the plant.
What can I plant after black turtle beans?
Anything leafy that benefits from nitrogen — cabbage, spinach, lettuce. Cut the stems at soil level and leave the roots in the ground.
Final Thoughts
Black turtle beans are the least demanding way to grow your own protein. No trellis, no feeding, one sowing, and a harvest that keeps for two years in a jar. The only thing they ask for is patience at the start — warm soil, and the discipline not to sow a fortnight early.
Grow a row alongside your snap beans: pick the snaps fresh through summer, and leave the black turtle row alone until the pods rattle in September.
More Bean Guides
- How to Grow Beans: Pole, Bush and Drying Types
- How to Grow Broad Beans
- How to Plant Black Turtle Bean Seeds
- How to Start Black Turtle Beans Indoors
- When and How to Harvest Black Beans
- Health Benefits of Black Beans
Never miss out on future posts by following us! Drop a comment below with your black bean questions, how you dry and store yours, or the variety that crops best where you garden, and let's grow something beautiful together.
Affiliate disclosure: This website is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon. Some of the links to products on this site are affiliate links. These are products that I've used or recommend based on my homesteading experience. I do make a small commission (at no extra cost to you) from these sales.