Vegetablefruiting vegetableSome care needed

Sweet pepper

Capsicum annuum

A tomato's requirements with less tolerance. Sweet peppers want more heat, for longer, and give up on ripening sooner — which in Britain makes them a protected crop in practice. Under glass they are unfussy and productive; outdoors they usually produce small green fruit that never colours.

Position: Full sun
Water: moderate demand
Drainage: Free-draining, Moisture-retentive
Grows to: 45–90 cm × 40–50 cm
Hardiness: H1C
Harvest: July to October
Difficulty: Some care needed

Described view

A bushy sweet pepper plant in a container carrying both green and ripening red fruit, showing the upright habit and brittle forked stems

August

Harvest

Sweet pepper’s year

Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.

Activity	F	M	J	A	S	O
Sow under cover	February.
Plant out		May.
Harvest			July.	August.	September.	October.

Names that cause confusion

pepper — Unrelated to black pepper (Piper nigrum). Sweet peppers and chillies are the same species, differing in whether they produce capsaicin.

Timing that travels

The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.

Sow under cover
8–10 weeks before your last spring frost
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Peppers — sowing
Checked 2026-08-13
Earlier than tomatoes: peppers germinate slowly and take longer to reach fruiting size.
Plant out
2–4 weeks after your last spring frost
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Peppers — planting
Checked 2026-08-13
Into a greenhouse or tunnel in most of Britain. Outdoors, only after settled warm weather.

Conditions it needs

Light: Full sun
Direct sun: 6–8 hours a day
Frost: Frost tender
Hardiness rating: H1c (RHS)
Grows best at: 21–30 °C
Germinates at: 21–27 °C
Soil: Loam, Peat-free compost
Soil pH: 6–7
Drainage: Free-draining, Moisture-retentive
Water needs: moderate
Drought: moderate tolerance
Waterlogging: poor tolerance
Heat: good tolerance
Wind and exposure: poor tolerance

Where these figures come from

LightSourced guidancehigh confidence: Royal Horticultural Society: Grow your own: peppers
Checked 2026-08-13
Direct sunHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
FrostSourced guidancehigh confidence: Royal Horticultural Society: Peppers — hardiness
Checked 2026-08-13
Hardiness ratingSourced guidancehigh confidence: Royal Horticultural Society: RHS hardiness ratings
Checked 2026-08-13
Grows best atSourced guidancehigh confidence: Home and Garden Information Center — Clemson Cooperative Extension: Peppers — temperature requirements
Checked 2026-08-13
Germinates atSourced guidancehigh confidence: OSU Extension Service — Oregon State University: Vegetable seed germination temperatures
Checked 2026-08-13
SoilHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Soil pHSourced guidancehigh confidence: University of Minnesota Extension — University of Minnesota: Soil pH for vegetable crops
Checked 2026-08-13
DrainageHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Water needsHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
DroughtHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
WaterloggingHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
HeatHorticultural consensusmoderate confidence: Home and Garden Information Center — Clemson Cooperative Extension: Peppers — culture
Checked 2026-08-13
Wind and exposureHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

On your soil

Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.

Soil	Verdict	Why
Heavy clay	Works, with one condition	Sweet pepper will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Sandy	Grows well here	Sweet pepper grows perfectly well on sandy without special measures, though it is not the soil it would choose.
Chalky and alkaline	Works, with one condition	Sweet pepper will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5.The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground.
Loam	Prefers this soil	Loam suits Sweet pepper as it stands: The pH suits it: it wants 6 to 7, and this soil is in that range. The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
Silty	Prefers this soil	Silty suits Sweet pepper as it stands: The pH suits it: it wants 6 to 7, and this soil is in that range. The free drainage is exactly what it wants. The soil holds moisture, which saves a great deal of watering.
Peaty and acid	Works, with one condition	Sweet pepper will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Shallow over rock	Prefers this soil	Shallow over rock suits Sweet pepper as it stands: The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting.
Made ground and urban soil	Works, with one condition	Sweet pepper will crop on made ground and urban soil, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.

Not sure which you have? Four hand tests will settle it.

Space and spacing

Mature height: 45–90 cm
Mature spread: 40–50 cm
Rooting depth: 30 cm
Spacing: 45 cm apart
Row spacing: 60 cm

Where these figures come from

Mature heightHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Mature spreadHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Rooting depthHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
SpacingSourced guidancehigh confidence: Royal Horticultural Society: Peppers — spacing
Checked 2026-08-13
Row spacingHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

Measured centre to centre. Plants set closer than this compete for light and water long before they look crowded, and the crowding cannot be undone once they are in.

In a container

Minimum volume: 10–15 litres
Minimum depth: 25 cm

Where the container figures come from

Minimum volumeSourced guidancehigh confidence: Royal Horticultural Society: Peppers in containers
Checked 2026-08-13
Minimum depthHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

Well suited to a pot on a warm patio or in a greenhouse, where the compost warms faster than open ground. Stake the plant once fruit sets; a loaded pepper topples easily.

Where and how you can grow it

Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.

Method	Suitability	What it needs
Greenhouse	Well suited source Sourced guidancehigh confidence Royal Horticultural Society: Peppers under glass Checked 2026-08-13	Ventilation in high summer
Polytunnel	Well suited source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Container	Well suited source Sourced guidancehigh confidence Royal Horticultural Society: Peppers in containers Checked 2026-08-13	10–15 litres per plant; A warm sheltered position, ideally against a south-facing wall
Hydroponics	Well suited source Sourced guidancemoderate confidence Purdue Extension — Purdue University: Greenhouse pepper production Checked 2026-08-13
Raised bed	Workable source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	A warm sheltered site
Windowsill	Workable source Horticultural consensusmoderate confidence A bright south-facing sill provides much of what a small greenhouse would. No external citation — see the evidence type above. Checked 2026-08-13	A compact cultivar; A south-facing sill
Open ground	Marginal source GrowingHQ editorial positionmoderate confidence In most British summers an outdoor sweet pepper sets a few small fruits that stay green. Recorded as marginal rather than unsuitable because in a warm year in the far south it does work. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13

Growing it

SowingSow at 21–27 °C. Peppers are slow and erratic to germinate below 20 °C, and a heated propagator makes far more difference here than it does for tomatoes.
FeedingFeed with a high-potassium fertiliser once fruit has set, as for tomatoes.
SupportStake plants carrying a heavy crop. Pepper stems are brittle and snap at the fork rather than bending.
HarvestingPick the first fruits green to keep the plant producing, then let later ones colour. A plant allowed to ripen its first fruits fully sets fewer afterwards.
WateringKeep the compost evenly moist while the plants are cropping. Peppers get blossom end rot on the same terms tomatoes do — from irregular watering rather than from any deficiency in the soil — and the damage appears on fruit that set during the dry spell, not on the fruit that is on the plant now.
ProtectionPeppers are perennial in their native range and a plant can genuinely be carried through a second year, which is worth knowing because a second-year plant crops earlier and heavier. Cut it back by about two-thirds in autumn, bring the pot somewhere bright and above 10 °C, and water very sparingly through the winter — it will drop most of its leaves and look dead, which is normal. Outdoors it is frost-tender and finished by the first cold night.

Where this guidance comes from

SowingSourced guidancehigh confidence: OSU Extension Service — Oregon State University: Vegetable seed germination temperatures
Checked 2026-08-13
FeedingSourced guidancehigh confidence: Royal Horticultural Society: Peppers — feeding
Checked 2026-08-13
SupportHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
HarvestingSourced guidancehigh confidence: Royal Horticultural Society: Peppers — harvesting
Checked 2026-08-13
WateringSourced guidancehigh confidence: Royal Horticultural Society: Peppers — watering
Checked 2026-08-13
ProtectionSourced guidancehigh confidence: Royal Horticultural Society: Peppers — cultivation
Checked 2026-08-13

Is it worth putting under cover?

Whether it will grow there is on the methods table above. This is whether the space is well spent, which is a different question and usually the one being asked.

Structure	What protection is worth	What decides it
Greenhouse	Only possible under cover source GrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	Ripening heat. Peppers will make green fruit outdoors in a good year and rarely colour them, and the colour is most of the point.
Polytunnel	Extends the season source GrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	Overnight temperature. Glass holds overnight heat that polythene loses, so a tunnel runs cooler at night than a greenhouse in the same garden. For a crop at the edge of its heat requirement that difference decides whether the fruit ripens.

Growing it without soil

Nearly anything can be grown in a soilless system by somebody with enough equipment. The useful question is whether it is worth it, in which technique, and what goes wrong.

Well suited

An established soilless crop. Grown this way commercially or routinely by home growers, with predictable results.

source

Sourced guidancemoderate confidence

Purdue Extension — Purdue University: Greenhouse pepper production

Checked 2026-08-13

Behaves much like a tomato in a soilless system, with a longer season to maturity and the same light demand.

Techniques that suit it

Drip-fed mediumSolution is dripped into an inert medium around each plant. The most forgiving technique and the one that suits large, long-season, heavy crops.
Ebb and flowA bed of inert medium floods and drains on a timer. The medium holds moisture between floods, which makes it far more tolerant of interruption than NFT.

source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Root space: Moderate to large; a long-season crop suited to substrate.
Support: Staking, because pepper stems are brittle and snap at the fork under a crop.
source
Horticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
Lighting: Fully lit by lamps
pH band: 5.5–6.5

Where these figures come from

Root spaceHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

LightingHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

pH bandSourced guidancehigh confidence

Outside roughly this band, individual nutrients become unavailable even when they are present in the solution — which is why a crop can starve in a full reservoir.

Purdue Extension — Purdue University: Hydroponic solution management — pH

Checked 2026-08-13

What actually goes wrong

Warm solution. Above roughly 22 °C the water holds much less dissolved oxygen and root disease follows quickly, which is why summer is harder than winter in an indoor system.
source
Sourced guidancemoderate confidence
- Purdue Extension — Purdue University: Solution temperature and dissolved oxygen
Checked 2026-08-13
pH drift. The solution moves as the plants take nutrients up, and by the time deficiency symptoms appear on the leaves the cause is several weeks old.
source
Sourced guidancehigh confidence
- Purdue Extension — Purdue University: Hydroponic solution management — pH
Checked 2026-08-13

No nutrient recipes here

GrowingHQ records pH bands, which are measurable properties of nutrient availability, and deliberately records no EC or PPM targets and no mixing instructions. Published targets vary by cultivar, growth stage, water source and technique, and the figures that apply to your system are on the product you bought.

Harvesting

When it is readyGreen peppers are ready when full-sized and firm. Colour takes a further two to three weeks and brings a marked increase in sweetness.
How to pick itCut with secateurs; pulling tears the brittle stem.

Where the harvest guidance comes from

When it is readySourced guidancehigh confidence: Royal Horticultural Society: Peppers — harvesting
Checked 2026-08-13
How to pick itHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

Keep picking

Regular picking keeps this plant producing. Fruit or leaves left to mature signal it to slow down or stop.

What goes wrong

Problem	How often	Notes
Natural fruit colouring	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Purple shouldering and blossom-end darkening on the way to red. Not blossom end rot.
Blossom drop	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Blossom end rot	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Aphids	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Greenfly on soft young growth under glass.
Magnesium deficiency	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13

Start from what you can see

Grown with, grown after, grown instead

Every relationship states its mechanism. A pairing nobody can explain is a pairing nobody has checked, and it does not go in.

Closely relatedChilli pepper
The same species, Capsicum annuum, separated only by whether the fruit produces capsaicin. Cultivation is effectively identical, so guidance transfers directly between them.
source
Sourced guidancehigh confidence
Plants of the World Online — Royal Botanic Gardens, Kew: Capsicum annuum
Checked 2026-08-13
Same rotation groupTomato
Both Solanaceae sharing soil-borne problems and pests, so they belong in the same rotation group and should not follow one another.
source
Horticultural consensusmoderate confidence
Royal Horticultural Society: Crop rotation
Checked 2026-08-13

Safety and edibility

Which parts are edible
The fruit is the edible part; the foliage of Capsicum, like other Solanaceae, is not eaten.
source
Horticultural consensusmoderate confidence
- Royal Horticultural Society: Potentially harmful garden plants
Checked 2026-08-13
Use the fruit only.

Sources for this page

GrowingHQ editorial synthesis · Home and Garden Information Center · OSU Extension Service · Purdue Extension · Royal Horticultural Society · University of Minnesota Extension

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-13.