How to Grow Capsicums

Capsicums are one of my very favourite vegetables to grow. The plants themselves are quite attractive, but this is multiplied many times when the fruits themselves start to form.

Whats more, not all capsicums look just like the standard “bell peppers” that are typically available from shops; you’ll find there are a whole range of different types, colours, shapes and flavours to enjoy. Once you start to get your hands dirty, like me you’ll probably look forward to trying something new each year!


Planting Capsicum Seeds

Capsicums hail from the warmer parts of the world, and it’s critical to remember this when growing them in cooler climates.

The warmer you can keep them, the faster they’ll grow and the better your eventual harvest will be. Planting the seeds is no different, where a warm, moist environment hastens their germination.

I personally start my seeds in small 3-4″ plastic pots, filled with a good quality multi-purpose compost. There’s no need to be too careful – just scatter the seeds over the surface then add half a centimetre or so of compost ontop.

An alternative method, which takes longer to set up, but saves you time in the long run, is to use a seed ray with modules. Just plant one seed per module as the germination rates tend to be excellent among capsicums. I then soak the pot thoroughly, by placing it into a tray filled with water.

Once the compost is well dampened, the pot is removed from the tray and wrapped in a clear plastic bag. This serves a number of purposes. Firstly, it helps to keep the moisture in; you basically don’t need to water your seeds again until the seedlings start appearing.

Secondly, of course, it acts like a mini greenhouse, keeping the seeds warm during their initial stage. The fact that the plastic is clear means that the seedlings can also photosynthesize if I don’t notice that they’ve germinated for a day or two.

I then aim to keep these pots nice and warm. I actually use a low-wattage heat mat, as sold to pet keepers, and normally expect to see my seeds germinating within days.

When planting capsicum seeds it is important to appreciate that cropping takes quite a long time. This isn’t something you’ll want to be planting in May or June if you want to get the most fruit possible. Instead, I plant my capsicums bright and early in the year, often in February or March, in order to give them the longest growing season possible.

Potting Up Capsicum Seedlings

Once the seedlings start to appear the plastic bag can be removed, in order to give the seedlings plenty of space to grow. Within a few weeks you’ll find your healthy, green seedlings are already starting to outgrow their pot. Its then time to upgrade their accommodation.

I have found in the past that capsicums don’t tend to take well to repotting. It seems that disturbing their roots can have a negative effect on their growth, as they take a week or more to re-establish themselves.

This first repotting is therefore a sensitive time, and once the process is complete you may not see much growth for a while.

The process is quite simple. If you’ve planted multiple seeds in a large pot then gently tip the compost out of the pot, gently pick up the various seedlings by their leaves, and transplant them into individual pots. I tend to go for 3-4″ pots here, to give them plenty of room to grow.

If you opted to use the modules I mentioned then the process is much easier. Simply let the seed tray dry out slightly, then push each module from underneath. You should find that the whole thing – plant, compost and all – pops neatly out in one piece. This can then be transplanted into a larger pot. I like this method because it reduces stress on the plant, as the compost around it remains in place, meaning less shock to the root system.

Once the repotting is done, once again you’ll want to keep the plants warm and in a very light area (to prevent them getting leggy). Depending on how early it is in the season, the best option is a heated plant propagator, placed on a sunny south-facing windowsill. This offers the optimum growing conditions.

Alternatively, a windowsill or frost-free greenhouse may be used, but the typically lower temperatures here may lead to slower growth than the propagator method.

Growing Capsicum Plants

As the tiny plants grow and develop, and the weather starts to warm up, you can begin thinking about the final placement for your plants. Over the years I have tested numerous varieties under different conditions. While it can still sometimes be possible to get fruit outdoors, I have always got better results from growing them under glass. This means placing the plants either into a sunny conservatory or a greenhouse.

Capsicums seem to respond very positively to nutrient-rich soil, so choose a rich compost for your plants. They can be planted in containers of around 12″ across, in growbags (probably the cheapest option) or even in the ground, if suitable organic fertiliser has been added beforehand.

Give them the sunniest and warmest position possible, being sure to water them thoroughly in hotter weather. If your only option is to grow capsicums outside then also try looking for the warmest place possible. A south-facing terrace, patio or against a wall tend to work well, drawing the sun’s heat, and staying warm late into the evening.

Capsicum Flowering & Fruit Growth

Over time, as the plants develop, you’ll start to see tiny flower buds appearing at the top of the plant. These will grow over time, eventually opening up to reveal simple white flowers.

I have never had any problems with pollination, whether plants are grown indoors or out, and soon enough the flower head will drop off, and in it’s place a tiny fruit will appear.

This is the best time for me.

The earlier those flowers appear, the longer the fruits will have to develop. Observing those first tiny fruits appearing is always a wonderful sign; all the better if you see them in May or June, rather than in September. These fruits will grow over time and, at a suitable point, you’ll start to see the colour changing.

The whole process – from flower to ripe fruit – can take some months. This is why I recommend starting your plants very early in the season; too often I hear novice gardeners starting their seedlings in May or June, then being disappointed that their plants die off in Autumn before they bear fruit.

Note that some capsicums produce huge fruits in relation to their size, so some support is normally a good idea. I simply sink a garden cane of a suitable length into their pot, and use garden twine to gently tie them to the cane. As the plants grow taller you may need to tie them up several times.

Appreciate, also, that as your capsicum plants grow taller, so the stems will also get wider. Therefore don’t tie your plants tightly to the cane, but instead do so loosely, leaving plenty of space for the plant to grow.

Fruiting takes considerable effort by the plants, which uses up plenty of nutrients. It is therefore good form to feed the plants every few weeks using fertiliser during the fruiting season. I have found that liquid fertilisers designed for tomato plants tend to work well, and be available for a reasonable cost.

Harvesting Capsicums

The crisp, sweet flesh of a home-grown capsicum makes for a most memorable salad. Harvesting the fruits is a simple process, but be aware that the stem between fruit and plant can be quite thick. Snapping the fruits off can on occasion damage the plant, therefore, so it is a good idea to cut them off the plant using secateurs. This keeps the parent plant in top condition, so it can continue to ripen other fruits.

It is important to mention at this juncture that each capsicum plant tends to only produce a small number of fruits. Many plants may only give you 4 or 5 fruits; sometimes less. This means that if you want a large harvest in the summer, you’ll likely want to grow quite a few plants. Much of my greenhouse is taken up each summer with capsicums, which gives me an ongoing glut for much of the summer period.

The fruits should be stored in your fridge, where they should keep for a week or more.

End of the Season

All too soon, the growing season comes to an end. By early September the days will become noticeably shorter, while the temperature will drop. Your days of capsicum growing are now numbered, so it’s important to do everything possible to maximise your yield. Fortunately, there are two tips which can help with this…

Firstly, if you start to see the weather changing then remove some of the unripened fruit completely. This will allow your plants to focus all their attention on just the handful of remaining fruits, and therefore speeds up ripening.

Secondly, I have found that keeping plants under glass can significantly extend the growing season. Even if you’ve had your pots out on the patio all summer long, if the fruits haven’t yet ripened properly consider bringing them indoors.

I had some capsicums growing in a border in my garden some years back, but a cold summer had prevented the fruit from ripening. In September I dug them up, popped them in a pot, and placed them in a cold, unheated greenhouse. If I’m honest I wasn’t expecting much, but I didn’t want to waste all those green peppers.

To my surprise, the plants flourished, and over the next few weeks I ended up with dozens of extra red peppers to enjoy. Translocating your plants to a greenhouse or sunny windowsill can be well worth the modicum of effort required, therefore, if you want to get as many fruits as possible.

When winter really kicks in the plants will die off. Simply pop them on the compost heap, and start preparing again for next year.

Saving Capsicum Seeds

If there’s one thing that frustrates me as a cook, it’s getting all those annoying little seeds out of your peppers when preparing them! Fortunately, from a gardeners perspective this profusion of seeds is great news! I have strains which have been through generation after generation with me; each year I save some seeds, and replant them the following spring. This saves me money, and of course it also avoids the chance of your garden centre selling out.

Saving capsicum seeds is simplicity itself. Simply cut open one of your fruits, then scrape the seeds onto a tray. Pop the tray on a sunny windowsill where the warmth will dry them out nicely. Check regularly, and turn them as necessary, to ensure even drying. Once they’re dry and crisp, simply pop the seeds into a labelled envelope, and pop them somewhere safe till next spring.

Capsicum Varieties

One of the real pleasures of growing capsicums is just how many varieties there are. For this reason I tend to grow one or two “tried-and-tested” varieties each year, which I know will produce plenty of fruit, and then a handful of “experiments” too. In this way I’m guaranteed peppers for my effort, but I also get to experiment!

Over the last few years I have found three varieties that seem to fruit more reliably than any others, and so these have become my “staple” capsicum varieties. They are:

California Wonder – Possibly the best and most reliable variety of all, producing beautiful thick-walled flesh. These are probably the closest to the variety seen in most supermarkets and are very easy to grow indeed.

Corno di Toti Rosso – Entirely different to the previous variety are these “bull’s horn” peppers, which can grow to 20cm long or more. Thinner walled than California Wonder, these plants seem to produce incredible volumes of fruit for their modest size. Truly a talking point when you have visitors round!

Minibel Orange – At the opposite end of the spectrum, this variety produces dozens of tiny little orange “bite sized” peppers – ideal for lunchboxes. They’re sweet and tasty, and look just as good as they taste.

Enjoy salads more this summer with your own supply of home-grown sweet peppers or capsicums. A perfect read for beginners and experienced gardeners alike; find out how to grow your own peppers at home the easy way!