Chillies Growing Guide
Chillies (Capsicum) are tender plants that produce a huge array of colourful, glossy fruits with varying shapes, flavours, and heat levels. They are closely related to sweet peppers and make attractive plants. They grow well in containers, with compact varieties reaching 20–30cm tall, allowing multiple varieties to be grown even in small spaces. They need heat and lots of sunshine to fruit well.
This guidance applies to the crop in general. Individual varieties and local conditions can differ.
Planting information
Sow seeds indoors from late winter to mid-spring to ensure a long growing season. Chilli seeds need warmth to germinate, around 21°C, preferably using a heated propagator or a warm windowsill. Once seedlings appear, remove them from the propagator and keep them at 16–18°C in bright light, watering regularly. When seedlings are 2–3cm tall, move each into its own module or small pot of peat-free multi-purpose compost. Once roots show through drainage holes, move them into larger 13cm pots. Young chilli plants should be kept indoors until at least late May. Plant them in their final container in a greenhouse or protected location. For outdoor planting, ensure night-time temperatures are reliably at least 12°C (usually late May or early June) and harden them off for two to three weeks. Choose the warmest, sunniest spot outdoors, ideally by a south-facing wall or patio. Plant at the same level as they were in their pot and add canes for support for taller varieties. For containers, plant one in a 22cm pot with peat-free multi-purpose compost, or three in a standard growing bag. For in-ground planting, choose well-drained, fertile, moisture-retentive, slightly acidic soil. Dig in moderate amounts of well-rotted manure (avoid fresh or large quantities). Warm the soil with cloches for a couple of weeks before planting. Space chilli plants 38–45cm apart, or 30cm for dwarf varieties. Cover young plants with cloches until the end of June for wind protection.
Harvesting information
Chillies are generally ready for harvesting from mid-summer into autumn in a greenhouse, and by August outdoors. Towards the end of the season, bring plants indoors to help remaining fruits develop. To maximise your crop, pick chillies when still green; they can be used at this stage or ripened further off the plant. Leaving fruits to ripen on the plant will change their colour and may increase heat, but will reduce overall new flower and fruit production by 25% or more. However, some prefer to let fruits mature on the plant for richer, hotter flavour and decorative appeal, despite a smaller harvest.
Storage information
Harvested chillies can be easily dried or frozen for storage, allowing enjoyment throughout the winter.