Chilli crop sheet

Information sheet

Don’t have a greenhouse? Not a problem. Chilli plants can be easily grown indoors on a sunny windowsill. Here are our top tips on how to grow them.

  • School term: Early Spring, Late Spring
  • Level of experience: No experience needed
  • Subject(s): Science

Sowing

When: February to April

  1. Sow seeds on the surface of pre-watered composted in a seed tray or large pot.
  2. Cover with a thin layer of compost or vermiculite and label with the variety and date.
  3. Place the tray or pot into a propagator until the seeds germinate (usually after 7 days or longer), ensuring the soil is kept moist.

If you don't have a heated or unheated propagator, try recycling a clear plastic bag or plastic bottles.

Growing

  • Once the seeds have germinated, remove the tray or pot from the propagator and check for watering whilst the seedlings are growing. Do not to over water the seedling as this may cause them to rot. 
  • The seedlings can be pricked out once they have developed their true leaves and are large enough to handle. Each seedling will need to be in an individual 7.5cm pots to give the seedling enough space to grow. Place the pots onto a sunny windowsill away from draughts.
  • Water regularly and feed every two weeks once the first flowers have appeared. You can use plant food that is specifically for chillies or otherwise one that is suitable for tomatoes.
  • Pot on into larger containers when the plants have outgrown their pots.
  • In milder parts of the UK, you can plant them outside when the danger of frost has passed or put them into the greenhouse or polytunnel.
  • Larger chilli plants require staking and pinching out to keep them compact.
  • If you are growing your plants indoors, your chilli flowers may not have been pollinated by visiting insects, you could give them a helping hand by cross pollinating them with a fine paint brush. To cross pollinate, move the brush in a circular motion around the centre of the flower. Pollen will stick to the bristles on the brush and be deposited onto the stigma where pollination takes place.

Harvesting

When: 9 to 17 weeks after sowing (depending on the variety)

  • Chillies are generally ready to harvest from July and can be removed using secateurs or clean scissors.
  • Check the varieties you have sown to get an idea of the size, shape and colour of the ripe fruit.
  • Picking fruit regularly helps to encourage plants to produce more.

Additional information

  • Instructions on how to make a propagator from a 2 litre drinks bottle here.
  • Care must be taken when touching the fruit so it may not be a suitable crop for younger children to grow.
  • Wear gloves if unsure about handling the fruit and wash hand thoroughly once you have finished handling them.
  • Some chillies are perennial, which means that they can live for several years, however they will need to be protected from cold during the colder months, even indoors.

Using chillies

  • The fruits can be used as they are or dried. Some of the larger varieties can even be stuffed with different fillings.
  • Make your own chilli flakes by drying and crushing them. Remember to store in an air tight container.
  • Why not try growing some chilli plants competitively as part of a 'Chilli Challenge'?
  • Dry the fruits and use them in craft projects or as decorations in floral arrangements and Christmas wreath.