Chilli is sweet pepper's genuine cross-partner -- commonly the same species, Capsicum annuum -- but the two diverge in two useful ways. Chilli is more heat-tolerant than sweet pepper, and unlike pepper it's a real storage crop: dried properly, chillies keep for years, turning a fresh summer harvest into a shelf-stable staple. It's also a short-lived perennial rather than a strict annual, and a healthy plant can be overwintered indoors to skip starting from seed again.
Water need
Consistent moisture supports steady fruit development -- irregular watering checks growth and can affect fruit quality and heat level.
Calories at a glance
400 kcal/kg -- the highest-calorie crop in this category, though eaten in small quantities as a flavouring (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
- Start under cover, very early. Sow seed under cover in January or February -- chilli needs an even longer head start than sweet pepper to ripen fully by the end of the season.
- Plant out only once it's reliably warm. Chilli has essentially no frost tolerance outdoors -- wait until night temperatures are consistently above about 15-16°C before planting out.
- Keep watering even. Consistent moisture supports steady fruit development -- irregular watering checks growth and can affect fruit quality and heat level.
- Harvest as fruit ripens. Pick chillies green for a milder flavour or leave to ripen to full colour for maximum heat and flavour -- either is fine depending on what you're using them for.
- Dry a portion for long-term storage. String or lay out ripe chillies to air-dry somewhere warm and well-ventilated -- properly dried chillies store for years, turning a fresh summer crop into a shelf-stable one.
Sowing & Harvesting Calendar
Pick your zone under "Temperature Range by Month" above and this updates too. Notice the Sow row starts earlier than sweet pepper's in most zones -- chilli's longer season to full ripeness means an even earlier under-cover start pays off. Boreal and Alpine show no window at all, the same as sweet pepper.
Calories & Yield
Chilli is the highest-calorie crop in this category at about 400 kcal per kg, though it's eaten in small quantities as a flavouring rather than in bulk. Subtropical and Mediterranean zones give the best yields here, and Boreal and Alpine aren't viable at all.
| Climate Zone | Yield per plant | Calories per plant | Viability |
|---|---|---|---|
| Tropical / Humid | 0.3 kg | 120 kcal | Viable |
| Subtropical | 0.4 kg | 160 kcal | Viable -- best yield |
| Mediterranean | 0.4 kg | 160 kcal | Viable -- best yield |
| Temperate Maritime | 0.2 kg | 48 kcal | Viable -- challenging, protection needed |
| Temperate Continental | 0.3 kg | 120 kcal | Viable |
| Cool / Boreal | -- | -- | Not viable |
| Arid / Semi-Arid | 0.3 kg | 120 kcal | Viable |
| Highland / Alpine | -- | -- | Not viable |
Figures per plant, from the site's own crop database. Maritime's yield already reflects the 60% penalty the calculator applies where the zone is rated "challenging" rather than fully viable.
Varieties Worth Knowing
Chilli varieties span a huge heat range -- worth knowing roughly where each sits before committing a row to it. 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
Most chillies are Capsicum annuum, the same species as sweet/bell peppers, and will cross with them. The exception is the hottest habanero-type chillies, usually a different species (C. chinense) that doesn't cross with the rest.
SERVINGS, NOT DAILY CALORIES This works out plate-sized servings of chilli 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 chilli -- 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
The site's own crop data highlights drying as chilli's real storage strength -- unlike sweet pepper, dried chillies store for years, not months, making this a genuine shelf-stable staple rather than just a fresh-eating crop.
String whole chillies to air-dry in a warm, well-ventilated spot, or slice and dry them for faster results -- either way, once fully dry and stored somewhere cool and dark, they keep their heat and flavour for a genuinely long time.
Growing Chilli Without Bought Inputs
Aphids are the main pest to watch for, sharing the same pressure as sweet pepper, especially on plants grown under cover.
Encouraging natural predators like ladybirds is a genuinely effective input-free defence against aphids, the same approach as for sweet pepper.
Overwintering a healthy plant indoors doubles as a way to skip a full growing cycle from seed -- less time as a vulnerable seedling means less overall exposure to pests each year.
Frequently Asked Questions
Does chilli cross-pollinate with sweet pepper?
Yes, genuinely -- chilli and sweet pepper are commonly the same species, Capsicum annuum, and cross freely if flowering nearby. If you're growing both for seed in the same year, keep them well apart or stagger which one is flowering.
Why does the crop database say chilli can overwinter indoors?
Because chilli plants are genuinely short-lived perennials, not strict annuals -- a healthy plant brought indoors before frost and kept in a bright, cool spot over winter can resume growing and fruiting the following season, skipping a full year of starting from seed again.
How cold and hot can chilli survive?
Roughly 0°C to 38°C -- genuinely more heat-tolerant than sweet pepper, matching the crop database's own note that chilli handles heat better than its sweeter relative. Frost is still fatal outdoors, and growth slows sharply below about 16°C.
Why is chilli not viable in Boreal or Alpine zones on this site?
The same reason as sweet pepper -- both zones lack the sustained warm season chilli needs to flower and ripen fruit, and chilli's total lack of outdoor frost tolerance rules out stretching the season the way a hardier crop could.
Is chilli a good calorie crop for self-sufficiency?
Modest -- around 400 kcal per kg, the highest-calorie crop in this entire category, though still eaten in small quantities as a flavouring rather than bulk food. Its real value is genuinely long dried storage and heat, not calories at scale.