Peppers are an underrated vegetable in my opinion. It’s super versatile, tasty, and healthy. Yet, not too many people are growing sweet peppers in the UK.
I want to change that. Did you know that they are a great source of dietary fibre while being low in calories? Bell peppers also contain many vitamins and minerals, as well as other compounds that will support your health.
Wether you add you them raw to your salad, on your pizza, in your sauces and curries, or roast them, they are a great addition to a healthy diet.
And homegrown peppers have much more taste then shop-bought ones, and are sweeter. Best of all, they are so easy to grow.
This guide will tell you all you need to know to grow your own delicious peppers here in the UK.
Sweet Pepper Varieties To Grow In The UK
Let’s start with looking at the different varieties you can grow. Choosing the right variety for you is important if you want to grow bell peppers successfully.
Both sweet and chilli peppers are part of the nightshade family, like tomatoes, aubergines, and potatoes. As such they’re warmth-loving plants and thrive in a greenhouse or polytunnel.
But there are also varieties that can be grown outside in the UK. And even if you don’t have much space or only a balcony or window boxes, there are varieties that will suit your space.
Here are some of the best bell pepper varieties you could try:
- Californian Wonder – this is a heavy cropper and will give you beautiful red peppers. While they will do best under cover, they can be grown outside too.
- Cardinal F1 – this pepper plant will produce fruit that start off purple and turning into a rich red, which will look beautiful in your garden. This variety is best grown in a greenhouse or polytunnel
- Jester F1 – the snack-sized fruit this pepper variety grows is striped in different colours and turns red when fully ripe. It can be grown outdoors or under cover and will look stunning in your garden or meals.
- Black Knight F1 – the small purple-black fruit of this variety are super sweet and attractive. It can be grown under cover for early fruiting or outdoors, where it will set fruit later.
- Paragon – this bushy pepper variety is ideal if you have little space, and can be grown in pots, window boxes and windowsills.
- Corno Di Toro Rosso – this long red pepper is a firm favourite with gardeners thanks to it delicious flavour. Grows best in a greenhouse/polytunnel and is well suited for growing in containers or grow bags.
Which variety you’ll choose will depend on the space you have, whether you have a greenhouse or polytunnel, and your preference.
Growing Sweet Peppers In The UK Step-By-Step
Now that we have talked about varieties and you know how to choose the one that fits best with your garden or growing space and preferences, let’s get to it.
We’ll talk you through every step of the way to grow your own sweet, delicious, and healthy peppers.
Step 1: Sowing Your Seeds
It all starts with a tiny, perfect seed, which you can start sowing as early as February and as late as March/April, like their fiery cousin the chilli pepper.
You need to start you pepper plants off in doors, as the seeds need warmth to germinate. Fill a small seed pot with good quality peat-free compost. Water the pot so the compost is nicely moist.
Put two seeds per little container and press them in slightly. Then add a layer of compost to cover them.
Put the pots on a sunny windowsill or in a propagator in a greenhouse/polytunnel. Pepper seeds need temperatures between 18°C and 21°C (64°F and 70°F) to germinate.
Keep the compost moist but not wet, as too wet conditions can make the seeds rot.
In the right conditions your seeds will germinate in 7 to 21 days. Once the the green shoots have come through, keep them at 16°C (60°F) minimum.
Step 2: Transplanting Your Seedlings
Once your seedlings have grown two true leaves (these are the leaves that grow after the initial two), transplant it into a slightly bigger pot, one per container this time.
Be careful when handling the seedlings, as they are still very fragile. Take special care not to damage the roots of the young plants.
Continue to do this until they are ready to be planted into their final spot, whether this is a in a bed in a polytunnel/greenhouse, outside, or a container or window box.
Water your seedlings regularly. You want the compost to be moist, but not wet.
Step 3: Finding The Perfect Spot
As we have already said, sweet peppers need warmth and most varieties will do best in a polytunnel or greenhouse. We always grow our peppers in our polytunnel, and every year we get a great yield.
But if you don’t have the luxury of either, there are varieties that can be grown outside, especially in the parts of the country that have a warmer climate.
To give your bell pepper plants the best chance outside, select a sunny spot, where the plants will get a lot of sun. It should also be a sheltered spot, to protect the peppers from harsh winds.
If you decide to grow your peppers in pots, a patio is ideal or even a balcony will work. Or just a sunny, sheltered spot somewhere in the garden. I know people who grow their peppers in pots in their conservatory.
The right spot also has to have the right soil. You want it to be well-drained and nutrient rich. The best way to achieve this is by digging in a good amount of well-rotten organic matter in spring.
Or, if you have a no-dig garden, add a layer of organic matter, such as leaf mulch or homemade compost to your soil.
The right time to plant your pepper plants in their final spot is in May for a greenhouse or polytunnel, and June, when there is no more risk of frost, outside.
These timing are general, and it might be slightly different depending where in the UK you are. Further north you might have to wait a bit longer, further south it might be earlier.
For peppers grown outside, make sure you harden them off first to get them used to the outdoor conditions. This means you put them outside during the day for a few hours for a week or two.
Every day or two leave them for a bit longer.
Step 4: Taking Care Of Your Pepper Plant
I have already said that growing sweet peppers in the UK is easy, so caring for them won’t take much time or effort.
First you have to make sure they are well supported, as the weight of the fruit can be considerable, unless they grow small fruits or a bush variety.
The best thing to use is a sturdy bamboo cane. Stick it next to the plant after you have planted it in its final spot. As it grows, attach the main stem lightly to the cain with some jute string.
There is no need to pinch out the top of the main stem, unlike with tomatoes, unless the plant grows very tall. But most don’t tend to grow much taller than 30cm.
Water your pepper plants regularly but don’t overwater them. I tend to water them every other day in our polytunnel. Unless it’s really hot for prolonged periods, then I water them more often.
Outside, do the same during prolonged dry periods, otherwise adapt your watering routine to the weather.
If you’re growing your bell peppers in containers, keep in mind that the soil will dry out quicker, so more frequent watering might be necessary.
Once the plants start flowering, it’s time to feed them. Like with tomatoes, at this point feed them with a high-potash liquid fertiliser. I have used this one for years and it works great.
However, nowadays the only liquid feed I use is the fertiliser from our wormery. It’s a magic substance that will make your plants thrive.
It doesn’t just contain a wide range of nutrients, including the vital potassium for fruit growth, but in addition it also contains beneficial bacteria, so-called probiotics. (Yatoo et al., 2021)
But there is more, the worms release a substance that kills pathogens, harmful microorganisms, which is transported in the the compost and fertiliser you get. (Alkobaisy et al., 2021)
So I can highly recommend getting your own wormery in addition to a compost heap, your soil and plants will thank you for it.
Step 5: Harvesting Your Own Homegrown Sweet Peppers
Harvesting generally starts mid-summer for peppers grown under cover. However, this will depend on the variety, as well as the weather conditions.
Some bushy varieties that grow smaller fruit might ripen sooner.
Knowing when to harvest the fruit is fairly easy, as they tend to turn red, yellow, orange, or even purple when ripe. That said, many varieties can also be eaten when green, although they are more bitter than the ripe fruit.
I love green peppers as a pizza topping, so I always pick some before they have ripened.
Peppers need sunlight to ripen, so make sure you remove foliage that is blocking out light from your peppers.
To harvest your sweet peppers, snap off them off at the stem, but be careful not to harm the plant.
Harvesting can continue into autumn, especially if grown in a greenhouse or polytunnel. We routinely harvest our last peppers we grow in our polytunnel in October.
If you grow your plants in pots on a patio, bring them inside when it gets cooler to ripen the remaining fruit.
Troubleshooting Any Issues
Here you go, these are your steps to grow sweet peppers here in the UK. While growing these fantastic plants is easy, you might hit some issues, as any gardener does at some point.
So we have put together a list of some issues you might encounter and how to solve them.
Pests And Diseases
Pests are part and parcel of growing your own fruit and vegetables, and should be tolerated as much as possible. They are an important part of your garden’s ecosystem.
It’s also worth saying that most plants can easily tolerate being nibbled at a bit, without any harm being done to them. It’s when a pest becomes an infestation that issues can occur.
The good news is that there aren’t that many pests to be aware of, only these three:
- Aphids – whitefly in a greenhouse or polytunnel
- Slugs
- Snails
Slugs and snails will eat pretty much any plant in your garden. But they are only really a threat to your pepper plants while they are young. The young and juicy leaves are just too good for these slimy customers to resist.
To avoid them being eaten fully rather than just nibbled at, don’t plant them out in your beds until they are well established. If start sowing them indoors in February, this will happen naturally, as you won’t be able to bed them out until May or June.
You can also put physical barriers up to prevent the slugs and snails from reaching your pepper plants, such as these copper rings.
- Protect your plants from slugs and snail by placing these best selling Copper Slug Rings around them. This pack contains 6 x LARGE Copper Slug Rings (17cm / 7″ in diameter)
- These solid Copper Slug and Snail Rings will last for many years and are simply placed around the plant where they form a barrier which slugs and snails will not cross. Slugs and snails hate copper because of reaction between their mucus and the copper.
- When the slugs and snails come into contact with the ring they are repelled and will crawl away. They are easy to use as a spring clip allows you to open the ring. Slip it around the stem and then press lightly into the soil. If you have larger plants, just link them together to make a bigger ring.
Aphids are another common garden pest and the best way to deal with them is by:
- Encourage beneficial insects to your garden that will eat aphids, such as ladybirds, lacewings, and hoverflies
- Use companion planting to repel these sap sucking insects – basil is ideal under cover, garlic, onions, and chives work great outdoors
These are the two methods I use for all my veggie plants and it works a treat. Yes aphids still are on my plants, but they don’t cause an issue, because their numbers are kept down naturally.
In terms of dieseases, there aren’t many to worry about. Grey mould can affect peppers. This is a fungal disease that can occur in warm, humid conditions, that might arise in a greenhouse or polytunnel.
Make sure you keep your growing space well ventilated by opening windows or doors during hot days. When you plant your seedlings out, keep them 40cm – 45cm (16in – 18in) apart.
This will increase air cuirculation, reducing the risk of creating humid conditions for grey mould to thrive.
Peppers Not Flowering And/Or Fruiting
If your pepper plants have healthy foliage but doesn’t produce flowers or the flowers don’t turn into fruit, several things might be the cause.
1. Lack Of Nutrients Availability
For plants to grow flowers and subsequently fruits, they need potassium, including sweet peppers. Studies have shown that adding potassium or potash will increase the number of flowers and fruits. (Akram, 2017)
So if you find that your pepper plants aren’t flowering/fruiting well, feed them with a liquid fertiliser high in potash.
- Easy to apply simply mix with water in a watering can according to instructions
- For tomatoes and flowering pot plants
- With seaweed extract for maximum growth and better crops
2. Water Stress
Not getting enough water can also be a reason why pepper plants produce flowers but then drop them without a fruit forming. (Wubs et al., 2015)
So make sure your keep your sweet pepper plants watered well, especially during prolonged hot and dry periods. Remember, if you grow your peppers in containers they might need watering more, because soil in a pot dries out quicker than a bed.
3. Too Hot
Although peppers need consistent warmth to thrive, if it gets too hot, they won’t produce flowers or fruits. If your pepper plants start to flower, but then drop them without furiting, it could be too hot. (Erickson, 2001)
It might not seem a likely scenario in the UK, but especially if grow your peppers in a greenhouse or polytunnel, the air temperature might get too high.
The above mentioned study has shown that at 33°C (91°F) the pepper plants continued to produce flowers, but didn’t set fruit.
And a greenhouse or polytunnel can easily reach this temperature in summer, even in the UK. So it’s important that you open windows and doors to keep up good ventilation.
When it gets really hot, which seems to happen more often now, I wet the floor of our polytunnel as well as opening both doors. This lowers the temperature for my veg plants.
4. Lack Of Pollination
Most vegetable plants need to be pollinated to produce fruit, including peppers. And while there are some self-pollinating varieties, most still need pollinators, like bees.
If your flowers don’t turn into fruit, make sure pollinating insects can reach them. Leaving the door to your greenhouse or polytunnel open can help with this.
It’s also useful to encourage pollinators to your garden, by planting pollinator-friendly flowers, for example.
Fruits Have A Dark Patch On Bottom
This phenomenon is called blossom-end rot and occurs in many fruting plants, including tomatoes and peppers.
Often associated with a lack of calcium, it’s actually caused by stress. (Suare, 2014)
What causes the stress can vary, from too hot temperatures, to lack of vital nutrients, and irregular or inssuficiecent watering.
To pin down the exact cause, trial and error might be involved, but if you persist, you’ll find the reason and can solve the issue.
Stunted Growth
If your pepper plant isn’t growing, this could be caused by a lack of nitrogen or by it being too cold. (Kratky and Bowen, 1989)
As we have already said peppers need consistent warmth to thrive, which is why most varities are best grown in a polytunnel or greenhouse.
The typical British summer is often very varied when it comes to temperatures, which makes it difficult to grow peppers well outside.
However, in certain regions of the UK, the weather is mild enough for outdoor growing. If you don’t life in such an area, a greenhouse or polytunnel might be your best chance.
Check our our recommendations of the best polytunnels for vegetable gardeners.
Now that you know all about growing sweet peppers in the UK, you’re ready to give it a go. Happy Growing!
