Our Organisation Search
Quick Links
Toggle: Topics

Sweet Peppers


Sweet peppers are tender plants which will require protection of a glasshouse or tunnel to produce successful crops in the Irish climate. In very mild areas it may be possible to get some small fruit maturing later in the summer if grown in containers in a bright sheltered spot in the garden.

Sweet peppers are available in a range of varieties. Shapes range from the traditional Bell, to the long tapered fruits. Sweet peppers are usually green and then mature to red, yellow, orange or purple depending on variety. The sweet flesh is used cooked in many dishes, in soups, sauces and added raw for a fresh sweet flavour in salads.

Sowing seeds

  • Similar to tomatoes but higher temperatures of 21-250C are required.
  • Where a small number of plants from a range of varieties are required, purchasing plants from the garden centre or garden shop is an option.
  • Select healthy plants that are not wilting and are free of disease. Check around the plant and the underside of the leaves for signs of pests.
  • Choose varieties and the number of plants required for space available.

Planting in the Greenhouse

  • Soil as for tomatoes or in compost filled containers or growbags.
  • After risk of frost has passed, plant out into growbags (2-3 plants per bag) containers or in border soil, after roots have filled the pot. Remove the pot, and plant at the same level as the compost in the starter pot.


  • A 90cm cane will be sufficient support for pepper plants grown in unheated greenhouses.
  • These plants will require little training and may be allowed to develop as a bush reaching 60-80cm in the growing season.
  • Heated greenhouses allow plants to develop faster and more careful training will be required.

Liquid Feeding

  • Sweet peppers are not as hungry as tomatoes and will not require as much feeding to maintain nutrient levels.
  • A high potash feed will encourage fruit development and intensify flavour and colour.
  • Feed at about half the strength of feed one would use for tomatoes or limit feeding to once per week. (Use tomato feed mixes according to manufacturer’s directions.)


  • The first flower or ‘King fruit’ must be removed as it will take too much energy from the plant before it puts on sufficient vegetative growth.
  • Remove any deformed young fruits to help maintain plant vigour. A strong sturdy plant will produce better quality fruit. Reducing the number of fruits will encourage larger, fleshier fruits to develop.
  • High temperatures will stimulate vegetative growth and temperatures below 120C will result in poor fruit set and misshapen fruit. Some form of heating may be required during spells of dull cold weather.
  • In prolonged periods of very strong sunshine high temperatures above 350C in the greenhouse will interfere with fruit-set. Shading and good ventilation can help.


  • Start picking fruit when they are green and the skin is smooth and shiny. Allow fruit to ripen up to red, yellow or orange for sweeter fruit but this will slow down development of new fruit.
  • Grow some plants to allow the fruit to mature and keep picking green fruits from other plants to ensure a continuous supply over the summer.
  • Cut the fruit from the plant using a knife or secateurs to leave a clean wound. Do not tear the fruit from the plant as it will cause damage which leaves the plant exposed to disease.