How to Grow Sweet Peppers

Colouful sweet bell peppers at farmers market

How to Grow Sweet Peppers

A far wider range of Sweet peppers is available as seeds than as produce in the shops. There are lots of varieties to grow in different colours, shapes, sizes and unique flavours!


Sweet peppers are not hard to grow from seed but need a long time to mature. It is therefore best to start sowing them early indoors or in your Harvst. Late winter is generally a good time. Smaller varieties may be grown till maturity in your Harvst whilst larger plants can be moved to a sunny, sheltered and warm position outside when the night temperatures are minimum 10-15°C.

Fill a pot, tray or multi-cell tray with peat-free compost and water it. Sow the seeds at least 2cm apart and cover lightly with compost or vermiculite unless it says on the seed packet that they need light to germinate. Water again carefully. Putting a plastic dome or cling film on top can help germination but make sure it has air holes for ventilation. Keep the soil evenly moist until the seeds germinate because if they dry out they will most probably not germinate at all. Having said that, be careful not to overwater! 

Peppers will ideally need 18-26°C to germinate well and normally appear within 7- 14 days. Some varieties can take longer to germinate. Once the seedlings appear, remove the plastic and place in a bright location with 12-16hrs of light. 18°C is an ideal growing temperature.

Plant care   

Transplant the seedlings to their individual 7-9cm pots when at least one set of true leaves have formed. Repot them into slightly larger pots when the roots start to stick out at the bottom aiming for a 30cm pot as the final one. 

Many growers recommend to pinch out the growing tip when the plant is about 20cm tall, to encourage branching, which should lead to more fruit. There is however a difference of opinion amongst growers of what is best. 

You can keep the pot in your Harvst if you have space or put it outside in early summer when the night temperatures are at least above 10°C. To acclimatise the plants to outdoor conditions, lift them outside in a sheltered, lightly shaded spot during the day, and put them back in at night. Gradually increase the time outside. Do this for about two weeks before leaving them out all the time. 

Try to keep the pots evenly watered and feed every 10-14 days with a balanced liquid fertiliser, changing to a high-potash feed every 7-10 days once the first fruits start to set. 

It’s a good idea to stake the plants to provide additional support, as the crop can be heavy.

When growing in your Harvst, pollinators may struggle to get to your plants so they will need help to pollinate properly. Stroke the inside of the flowers with a small paintbrush to pass pollen from one flower to another.  

Mist the foliage regularly when growing indoors or under cover with tepid water to discourage red spider mites and to help flower set. 


You can harvest Sweet Peppers at any colour you like but the flavour will change with ripening so ensure you check out the details of the particular variety you are growing.

Watch out! 

The biggest problem tends to be red spider mites. Avoid them by regularly misting the plants, especially if grown under cover. Whitefly and aphids can also be a problem which can be treated with an organic soap spray. Blossom end rot is a result of erratic watering but is not as common as on tomatoes. 

Pro Tip

If you are growing two plants of the same variety, pinch out the growing tip on one when it is about 20cm tall, to encourage branching, which should lead to more fruit. There is a difference of opinion amongst growers so see what you think!

Nerdy facts

Although Sweet peppers are treated as an annual plant in our climate it is actually a perennial. They can be overwintered indoors but growers often have mixed results in the second year.

Recommended Varieties

There are lots of different varieties but here are some that are suitable to grow in your Harvst and outdoors in a sheltered spot. 

‘Corno di Toro Rosso’ produces large, long and sweet red fruits up to 20cm long.and reaches a height of 150cm unless the growing tip is pinched out for a smaller but bushier plant.  

‘King of the North’ is a good early variety to grow outside yielding good-sized peppers. 

‘F1 Redskin’ is a dwarf pepper producing good yields of sweet-flavoured deep red fruit . 

‘Lunchbox Sweet Mini Peppers’ is a compact plant reaching a height of between 60-70cm tall producing lots of small delicious peppers. 

‘Mohawk’ is a dwarf bell pepper with a trailing habit producing high yields of fruit that mature from green to orange.