French bean is common bean (Phaseolus vulgaris) grown for fresh pods -- the exact same species as this site's Borlotti/Haricot, just picked young rather than dried, and a genuine cross-partner if both are left to flower. Its real trick is productivity: picked young and regularly, a single plant keeps setting new pods for a genuinely long season, since leaving pods to mature signals the plant to stop producing. At around 350 kcal per kg it's the lowest-calorie legume on this site, but the sheer volume a well-picked plant produces makes it worthwhile for fresh eating.
Water need
Even moisture through flowering and podding matters more than at any other stage for a good, sustained set.
Calories at a glance
350 kcal/kg -- the lowest-calorie legume on this site, similar in scale to fresh pea (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 Harvest
- Sow direct after frost risk has passed. Sow direct once all frost risk is over and the soil has warmed -- French bean is frost-tender and won't forgive an early sowing.
- Choose dwarf varieties for windy sites. Dwarf varieties are self-supporting and better suited to exposed or windy positions; climbing types are more productive but need a sturdy support.
- Keep watering steady through flowering and podding. Even moisture through this stage matters more than at any other point in the plant's life for a good, sustained set.
- Pick regularly, while pods are still young. Harvest every couple of days once pods start forming -- pick young and often, since leaving pods to mature signals the plant to stop producing new flowers.
- Eat fresh, or preserve a surplus. French bean doesn't store the way dried beans do -- eat fresh within a few days, or blanch and freeze, or pickle, any surplus from a productive plant.
Sowing & Harvesting Calendar
Pick your zone under "Temperature Range by Month" above and this updates too. Like Borlotti/Haricot, every zone here shows a spring sowing window only -- common bean's frost tenderness rules out an autumn-sowing option.
Calories & Yield
French bean is modest in calorie density at about 350 kcal per kg fresh -- the lowest-calorie legume on this site. Subtropical and Mediterranean zones give the best yields here, though the crop's real strength is its long, productive picking season with regular harvesting.
| Climate Zone | Yield per plant | Calories per plant | Viability |
|---|---|---|---|
| Tropical / Humid | 0.25 kg | 87.5 kcal | Viable |
| Subtropical | 0.30 kg | 105 kcal | Viable -- best yield |
| Mediterranean | 0.30 kg | 105 kcal | Viable -- best yield |
| Temperate Maritime | 0.28 kg | 98 kcal | Viable |
| Temperate Continental | 0.28 kg | 98 kcal | Viable |
| Cool / Boreal | 0.12 kg | 42 kcal | Viable -- challenging (60% yield) |
| Arid / Semi-Arid | 0.15 kg | 52.5 kcal | Viable |
| Highland / Alpine | 0.12 kg | 42 kcal | Viable -- challenging (60% yield) |
Figures per plant sown, from the site's own crop database. Boreal and Alpine's yields already reflect the 60% penalty the calculator applies where a zone is rated "challenging" rather than fully viable.
Varieties Worth Knowing
French bean (green bean) varieties differ mainly in growth habit -- bush types crop all at once, pole types over a longer season but need support. All the varieties below are open-pollinated (OP), meaning seed saved from them breeds true and is worth keeping under this site's seed-saving approach; none are F1 hybrids.
Seed Saving -- Quick Guide
French bean is Phaseolus vulgaris, the same species as kidney bean, pinto, navy, cannellini and borlotti -- all will cross with each other, but mostly self-pollinate so the risk stays low even grown close together.
SERVINGS, NOT DAILY CALORIES This works out plate-sized servings of french 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 french 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
French bean isn't described as a storage crop in the site's own crop data at all -- it's grown to be picked young and eaten fresh, typically within days.
For genuine long-term storage, grow Borlotti or Haricot instead and let the pods dry fully, or blanch and freeze any fresh French bean surplus -- this crop's role here is high-volume fresh eating through a long picking season, not a winter staple.
Growing French Bean Without Bought Inputs
French bean shares bean beetle and blackfly risk with Borlotti/Haricot, the same species.
Good spacing for airflow and picking off the worst-affected leaves early handles most pressure without any spray needed.
Like most legumes, French bean fixes some of its own nitrogen, a modest soil benefit worth factoring into a wider rotation.
Frequently Asked Questions
Does French bean cross-pollinate with Borlotti/Haricot?
Yes -- both are Phaseolus vulgaris, the same species, just grown for different endpoints (fresh pods versus dried seed). Common bean is mostly self-pollinating, so the risk is more modest than broad bean's, but it's real enough to matter if you're saving pure seed from more than one variety.
Why does picking regularly matter so much for French bean?
Because leaving pods on the plant signals it to stop producing more -- once a few pods are allowed to mature and start toughening, the plant redirects energy into finishing those seeds rather than setting new flowers. Picking every couple of days while pods are young keeps the plant in continuous production for a much longer harvest window.
How cold and hot can French bean survive?
It's genuinely frost-tender -- roughly 0°C to 32°C, with all frost risk needing to have passed before sowing or transplanting. Reproductive development is especially heat-sensitive, and sustained day temperatures above about 30°C significantly cuts yield, the same limits as Borlotti/Haricot.
Why is French bean only "challenging" rather than fully viable in Boreal and Alpine zones?
Both zones have shorter, cooler growing seasons than common bean's genuine warm-season needs, so the crop can still be grown there -- just at a real yield penalty, which is what the "challenging" rating reflects rather than an outright failure.
Is French bean a good calorie crop for self-sufficiency?
No -- at around 350 kcal per kg fresh, it's the lowest-calorie legume on this site. Its value is fresh eating and a genuinely long, productive harvest window with regular picking, not calorie density.