Capsicum annuum
Peppers are best grown under cover in Scotland, not in the open ground, so the choice of variety and how you use your greenhouse or polytunnel space are the two decisions that matter most.
Outdoor growing works only in the mildest gardens or a long, hot summer, so treat a greenhouse, polytunnel or large coldframe as close to essential for a reliable crop.
Preparing the ground
If growing in the ground, use well-drained, fertile, moisture-retentive soil, working in a few bucketfuls of garden compost or well-rotted manure if it's poor or heavy, or mulchingA layer of material spread over the soil around plants to suppress weeds, retain moisture, and improve soil structure as it breaks down. Full definition → the surface for a no-digA growing method that avoids turning the soil over, building fertility instead by adding organic matter on the surface. Full definition → bed. In containers, use a pot at least 30cm wide with peat-freeCompost made without peat, which is harvested from a slow-forming, carbon-storing wetland habitat that peat extraction damages. Full definition → multi-purpose compost: one plant per pot, or two to three in a standard growing bag.
Sowing
Sow indoors mid-February to early March for greenhouse cultivation, or late March to early April if you're aiming for eventual outdoor planting. Seed needs 18-21°C to germinateA seed sprouting: breaking dormancy and putting out its first root and shoot, given the right warmth and moisture. Full definition → (Teagasc gives 21-25°C) in a heated propagator or on a warm windowsill, then 16-18°C in bright light once through, with evenly moist compost. Pot seedlings on into their own 7.5-9cm pot once they have two true leaves.
Planting
Plant into a heated greenhouse from late April, an unheated greenhouse from mid-May, or outdoors from late May or June only in milder areas or a long, hot summer, once overnight temperatures are reliably above 12°C and after two weeks hardening offGradually getting young plants raised indoors used to outdoor conditions over 7–14 days before planting out, so cold, wind and direct sun don't shock or damage them. Full definition →. Space plants 38-45cm apart depending on variety, or 30cm for compact types. Cover young plants with clochesA small, portable clear cover placed over an individual plant or short row to trap warmth and keep off wind, rain and pests. Full definition → for wind and cold protection, ideally until the end of June.
Varieties
Redskin holds the RHS Award of Garden Merit, a UK-wide award rather than a Scottish one.
'Topepo Rosso' is an Italian heirloom with rounded, crisp, sweet fruits, 'Bianca' a mid-season variety with large fruits, and 'Jolly Giallo' has square-shaped, fleshy fruits with a mild, sweet flavour.
★ Our pick for Scotland
RedskinAGM
Compact, 45cm tall, ideal for containers, medium fruit from July
The compact pick built for greenhouse and polytunnel space.
Why this one: A compact AGMThe RHS's Award of Garden Merit: a UK-wide trials award for reliable performance, not a Scotland-specific recommendation. Full definition → pick with medium-sized fruit, ideal for containers. Greenhouse and polytunnel space is often the limit, rather than garden space, and Redskin's small footprint plus July cropping both work in its favour.
Also worth considering
Mohawk
Dwarf, 50cm tall, ideal for patio pots, bell-shaped fruit
An even smaller footprint than Redskin, ideal for patio pots and useful for a windowsill or the smallest greenhouse corner. The RHS growing guide lists it with the AGM, but its plant page shows no badge.
Corno di Toro Rosso
Large, tapering fruit up to 25cm, sweet, crisp, thin skin
Large, tapering, sweet fruit with a crisp texture and thin skin, also named by Gardener's World. It needs more space and heat than the compact picks above. The RHS growing guide lists it with the AGM, but its plant page shows no badge.
Best Sweet Pepper Varieties for Scotland → compares all named sweet pepper varieties head-to-head, with the practical detail that doesn't fit in a summary card.
Care
Keep temperatures above 12°C, ideally above 15°C: peppers thrive in warmth, but fruiting suffers above 30°C, so shade and ventilate a greenhouse in a heatwave. Raise humidity on hot days by damping down, pouring a full watering can over the greenhouse floor to evaporate. Keep soil or compost evenly moist: flower buds can drop if plants get too dry, and container plants may need watering daily in hot, dry spells. Feed weekly with a high-potash liquid fertiliser once flowering starts (Teagasc suggests about half the strength used for tomatoes); plants in enriched ground may need less.
Teagasc advises removing the first flower or fruit to set, the "king fruit", because it drains the plant's energy. Pinching outRemoving the soft growing tip of a stem to stop upward growth and make the plant branch out sideways instead. Full definition → the growing tip at about 30cm produces more, smaller fruits, though it can delay fruiting. Support with bamboo canes as the plant grows, adding more canes and soft twine for heavily laden side-shoots, which are otherwise prone to snapping.
Harvesting
Pick once fruit is swollen and glossy, at green or any later colour stage; most varieties ripen from green through to red, though some turn yellow, orange or purple, and the flavour sweetens as they ripen. Picking earlier keeps more fruit developing behind it, while leaving fruit to ripen fully on the plant slows further fruiting. As the season ends, cover outdoor plants with plastic-free fleeceA lightweight, breathable fabric laid or draped over plants to trap a little warmth and keep off frost, wind and some flying pests. Full definition →, or bring potted plants indoors, to help remaining fruit finish ripening. Peppers keep for a few days in the fridge.
Common problems
- Aphids target shoot tips and the undersides of leaves, so check both regularly.
- Glasshouse whitefly feeds on sap and leaves sticky honeydew behind.
- Blossom end rot shows as dark blotches at the base of the fruit.
See more problems
- Grey mould causes soft tissue decay, especially in humid greenhouse conditions.
- Red spider mite causes mottled leaves and early leaf loss, especially in a dry greenhouse.
Common questions
Do peppers really need a greenhouse or polytunnel in Scotland?
For a reliable crop, yes: peppers are usually grown under cover in the UK, and are only really successful outdoors in milder parts of the country or in a long, hot summer. See also: Pepper Myths →
Should I remove the first pepper that forms on my plant?
Teagasc advises it: the first flower or fruit, the 'king fruit', is removed because it drains energy the plant needs for growth. The RHS and Gardener's World don't mention it, so it is optional. See also: Pepper Myths →
Why is my pepper plant dropping its flowers?
Often dryness. Flower buds may fall off if plants get too dry, so keep the soil or compost evenly moist, especially in containers during hot weather.
Do I need to feed peppers as heavily as tomatoes?
Not necessarily: Gardener's World feeds weekly with a high-potash feed such as tomato feed once flowers appear, about half tomato strength is the Teagasc figure, and plants in enriched ground may need less (RHS). See also: Pepper Myths →
Sources
Show the 3 sources
- RHS: the under-cover-vs-outdoor recommendation, sowing method and temperature, transplant timing for heated/unheated greenhouse/outdoor routes, spacing, container growing, temperature tolerances and their effect on fruiting, humidity management, watering and its link to flower drop, feeding, pinching out and support, harvesting method and end-of-season fruit-ripening, six named varieties (five AGM), blossom end rot, aphids, grey mould, red spider mite, whitefly
- Teagasc: Teagasc: germination at 21-25C and poor fruit set below 12C, the 'king fruit' removal technique, high-potash feeding at about half tomato strength, cutting fruit with a knife or secateurs
- BBC Gardeners' World: Gardener's World: the under-cover recommendation, 10C night temperature for greenhouse planting, weekly high-potash feed such as tomato feed, pinching out at 30cm, and storage (a few days in the fridge)