Chilli & Hot Pepper Seeds: Biquinho to Carolina Reaper

Chilli seeds don't need a heated propagator. Sow them straight into the pot the plant will live in, about 1cm deep, lightly covered and watered. What they want is warmth: 25 to 28 degrees Celsius gives the highest germination rate, so a warm windowsill beats a cold greenhouse in early spring.

From 500 SHU to 2.2 Million: Pick Your Burn

Chilli heat explained: the Scoville scale

The Scoville scale does most of the choosing for you. It ranks every variety in Scoville Heat Units, from 500 SHU at the gentle end up to 2.2 million at the summit. Once you know where a pod sits, you know whether it belongs in a salad or in a bottle of sauce.

What SHU actually measures

SHU tracks the concentration of capsaicin, the compound behind the burn. The scale climbs steeply rather than evenly, so the step from Serrano to Habanero Orange is far bigger than the step from Anaheim to Jalapeño M. Figures are given as bands because ripeness, sunshine and watering shift the result from plant to plant.

Scoville table of every variety we stock

The full line-up side by side, mildest at the top. Compare before you sow, not after you bite.

Choosing by heat level

Anaheim Chilli Seeds start as low as 500 SHU, flavour with a warm edge rather than pain, and Biquinho sits in the same band, more fruity and tangy than hot. Step up through Jalapeño M Seeds and Serrano Seeds and you're into proper cooking heat. Past that it stops being about dinner: Dorset Naga Black, Bhut Jolokia and Carolina Reaper are for people who measure their sauce in drops.

Choosing by Capsicum species

The kitchen staples mostly belong to Capsicum annuum: Anaheim, Jalapeño M, Serrano, Cayenne Long Slim and Hungarian Yellow Hot Wax Pepper (Capsicum annuum) Seeds. The extreme end belongs to Capsicum chinense: Habanero Orange, Bhut Jolokia and Carolina Reaper, slower off the mark and more perfumed in the pod. Short, grey summer? Lean annuum. Chasing the top of the table? Lean chinense and give the plants a longer, warmer run.

Can't decide? The Spicy Variety Pack runs Anaheim, Jalapeño, Serrano, Habanero Orange and Carolina Reaper in one box, and we'd take that over a single pack of Serrano for a first season.

Sow in Spring, Then Sit on Your Hands

Sow under glass in spring and move the plants outside when the weather turns. Keep the soil moist but never soaked, because a drowned seedling is the most common way this goes wrong. Cling film over the pot with a few holes punched in it holds the humidity. Germination runs from a few days to over three weeks, the hotter varieties usually slowest, and a Bhut Jolokia that hasn't shown by day ten isn't dead. Don't tip out a pot that was about to sprout.

Pot Size Sets the Size of Your Haul

Bigger pot, bigger harvest, longer wait. Cayenne Long Slim Seeds reach about 75cm tall with wrinkled, twisted pods around 12cm long, and they'll do that in a container on a balcony. Once the seedling is up, pull the cling film off and give it as much light as you can find. A tomato feed covers the basics, and extra calcium as a foliar spray stops the fruits rotting at the tip.

Choosing by growing space: windowsill, greenhouse, outdoor bed

A bright windowsill is the safest start for any variety. A greenhouse pays off with the chinense types, which want that long stretch of warmth to fill out. For an outdoor bed or a big tub, wait for settled weather and pick the tougher growers: Hungarian Yellow Hot Wax copes with cold better than most and still hands you a pile of pods for the barbecue.

Picking by Colour, Not by Calendar

Wait for the fruit to let go

Days to maturity are only estimates: around 85 days for Jalapeño M and Cayenne Long Slim, roughly 95 for Anaheim, about 100 for Serrano. Judge by colour instead. Anaheim pods finish at 15 to 25cm and shift from green to red, while a ripe Serrano is 7 to 10cm and dark green just tipping into red. Tug gently, and if the pod resists, give it a few more days.

Keeping seed and pods

Leftover seed keeps in its sealed pack somewhere cool, dark and dry, ready for next spring. Fresh pods hold for a few days in the fridge, much longer dried or frozen whole. Wear gloves when you handle chillies and their seeds, and keep your hands off your eyes. If you cook most nights, Cayenne Long Slim is the pack we'd keep sowing year after year.