Per the crop database: edamame fresh or dried for tofu/tempeh, needing a warm summer to fill its pods. Soya bean (Glycine max) is strongly self-pollinating -- flowers typically pollinate themselves before they even fully open -- so isolation from other beans is barely a concern, and it's its own genus entirely, unrelated to common bean, runner bean or any of the Vigna beans on this site. Like other legumes, it fixes its own nitrogen as it grows.
Water need
Water matters most while pods are filling out -- even moisture through that stage has the biggest single effect on final yield.
Calories at a glance
4,000 kcal/kg dried -- a genuine calorie staple as well as a protein and oil crop (scale is log-based across all 55 crops in the calculator).
Temperature Range by Month
Month on the bottom, temperature up the side. The pale green background is what the plant can survive at all -- fatal above or below it, labelled directly on the chart where that applies to your zone. The coral band is its ideal range, and only fades in during the months this zone would actually have the crop in the ground -- reusing the exact same sowing/harvesting data as the calendar further down the page. The blue line is real monthly climate data (not a modelled estimate) for a representative rural/agricultural location in this zone -- a small farming town or agricultural research station rather than a major city, to avoid the warmer bias city weather stations have. For the actual verdict on how well this crop does in your zone, see the badge at the top of the page -- that's based on the site's own researched yield figures, not this chart.
Quick Start: Sowing to Storage
- Sow direct once soil is warm. Sow direct once the soil has genuinely warmed up -- soya bean is frost-tender and germinates poorly in cold, wet ground.
- Inoculate if growing it for the first time. If soya bean hasn't grown in that soil before, a rhizobium inoculant on the seed at sowing gets nitrogen fixation going faster.
- Keep soil evenly moist through pod fill. Water is most critical while pods are filling out -- even moisture here has the biggest effect on final yield.
- Pick young and green for edamame, or leave to dry. For edamame, pick pods while still green and plump; for dried storage, leave the plant standing until pods rattle and have turned brown and papery.
- Shell and finish drying indoors. Shell dried pods and spread the beans out somewhere warm and airy for a final week of drying before storing in an airtight container.
Sowing & Harvesting Calendar
Pick your zone under "Temperature Range by Month" above and this updates too. Boreal and Alpine show no window at all, since this site's own yield data marks soya bean as not viable in either.
Calories & Yield
Soya bean is a genuine calorie staple when dried at 4,000 kcal per kg -- among the highest of the dried pulses on this site. Tropical gives the best yield here.
| Climate Zone | Yield per plant | Calories per plant | Viability |
|---|---|---|---|
| Tropical / Humid | 3.5 kg | 14000 kcal | Viable -- best yield |
| Subtropical | 3.0 kg | 12000 kcal | Viable |
| Mediterranean | 2.5 kg | 10000 kcal | Viable |
| Temperate Maritime | 0.9 kg | 3600 kcal | Challenging (60% yield) |
| Temperate Continental | 2.5 kg | 10000 kcal | Viable |
| Cool / Boreal | -- | -- | Not viable |
| Arid / Semi-Arid | 0.9 kg | 3600 kcal | Challenging (60% yield) |
| Highland / Alpine | -- | -- | Not viable |
Figures per plant sown, dried weight, from the site's own crop database. Maritime and Arid already reflect the 60% penalty applied to challenging zones.
Varieties Worth Knowing
Soya bean varieties differ in seed colour and how they're typically used. Both below are open-pollinated (OP), meaning seed saved from them breeds true and is worth keeping under this site's seed-saving approach; neither is an F1 hybrid.
Seed Saving -- Quick Guide
Soya bean is highly self-pollinating -- one of the most forgiving legumes for seed saving, with very low crossing risk even between varieties grown side by side.
SERVINGS, NOT DAILY CALORIES This works out plate-sized servings of soya bean from your seed during its fresh harvest window only, not your group's full daily calorie needs. For that, use the main calculator.
Estimated for your selected zone above, using this site's own germination, loss and yield figures for soya bean -- a helping is roughly what you'd put on a plate as part of a meal with other veg. Treat it as a planning estimate, not a promise.
Storage & Preservation
Soya bean can be eaten fresh and green as edamame, or grown here specifically for dried storage -- pods left on the plant until fully dry, then shelled and given a final week of airing indoors before going into an airtight container.
Stored this way in a cool, dry place, dried soya beans keep for a genuinely long time -- years rather than months, the same storage league as wheat, oats and this site's other dried staples.
Growing Soya Beans Without Bought Inputs
Bean beetles and pod-boring caterpillars are the main pests to watch for, along with slugs on young seedlings.
Rotating away from the same ground each year and hand-picking pests off the plants are simple, genuinely effective input-free measures.
Soya bean fixes its own nitrogen via bacteria in root nodules, genuinely improving the soil for whatever's grown there next -- factor that into a wider rotation plan, not just a calorie one.
Frequently Asked Questions
Why is soya bean such a big deal as a crop?
Soya bean is the world's most important legume oil and protein crop by a wide margin -- grown at a scale no other pulse comes close to, precisely because it delivers both a genuine oil crop and a genuine protein crop from the same plant.
Does soya bean need isolation from other beans on this site?
Barely -- soya bean is strongly self-pollinating, with flowers that typically pollinate themselves before they even fully open. It's also its own genus, Glycine, so it doesn't cross with common bean, runner bean, cowpea or any of the Vigna beans on this site regardless.
Why isn't soya bean viable in Boreal or Alpine zones on this site?
It's a genuine warm-season crop that needs a real summer to fill its pods, and it's frost-tender at both ends of the season -- exactly the combination that a short, cool Boreal or Alpine growing season can't provide.