My Outdoor Chilli Plant Isn’t Growing!

About 3 weeks ago I wrote a piece on moving chilli plants outdoors. It is often difficult to judge when it is OK to do it, and it is always a compromise, it is where I live anyway.

So I thought I’d update people as to what my plants are up to. Generally, I keep all mine in the greenhouse until they grow so big I have no choice, and if any go outside I’m always picky and try to keep the best ones under glass.

This time, just as an experiment I planted one outside on our patio in a stone pot to see what happens. I did this much earlier than I would normally do, but in doing so I was mimicking the dilema which most chilli growers that don’t have a greenhouse. I also put one in a raised bed, and kept the others from the same batch inside.

And after about 3 weeks, here are some results.


The outdoor plant has had some pretty good weather, not perfect, but OK. It has had warm days and cool nights to start with, some rain, a fair bit of wind, and not too much in the way of pest damage, just a couple of nibbled leaves as you can see. But this has still taken its toll, down to 8°c on some nights, some cool winds and a max of maybe 23°c in the day times isn’t ideal. The leaves are curled and quite tough, but mainly the plant has grown slowly, maybe 20cm high and hardly branched out with not many extra leaves, though it is starting to flower.

I stress that this plant hasn’t been neglected at all, it has beeb watered whenever it needed it, fed, staked, and moved about to shelter it from the worst of any wind.


The one in the raised bed (above), has fared better. The leaves have toughened, but not curled much, it has more side shoots and the flowers are more developed. This is because it has been protected from the elements with green mesh around and over the bed too stop the wind and raise the temperature, the soil temperature is warmer and more stable too.


The third one (above), has been kept in the greenhouse all the time, and has grown a lot more. It is taller and probably has twice the amount of foliage than the outdoor one, there are more side shoots, more flower buds and it is looking generally more healthy.

All these plants are the same variety, grown alongside each other until they were separated for this experiment. They are a variety called Nigel’s Outdoors, not one I have grown before, nor one I am familiar with. The seeds came to me as part of a swap I did with Alex the Air-Pot Gardener, a friendly chilli grower here in the UK. I assume it has been bred, (no doubt by someone called Nigel), to be more tolerant to the conditions of my experiment. Other varieties may not have fared even as well as this one. I suspect a similar experiment with habanero plants would have resulted in the outdoor plants not growing at all.

So what is the lesson here?

  • In temperate climates keep your chilli plants indoors for as long as you can, it will pay dividends.
  • Don’t expect too much from your chilli plant if you put it outdoors before the warm summer nights and while it is still young and tender.
  • The outdoor plant won’t grow as quickly and you won’t get as much of a crop.

Watch this space for another update in a few weeks. I suspect we might be picking fruit of the one in the greenhouse.






When can my chilli plants go outside?

Let’s be honest, unless you live in a Mediterranean or tropical climate, you will, like me and millions of other chilli growers, be looking to put plants outdoors as soon as you can because your window, conservatory, polytunnel, or whatever, is never big enough to house all of your chili plants. It is never big enough because we always grow too much, it’s a bad habit.

I grow too much, I don’t need as many as I grow, I give them away, which brings me joy, but still I end up with an overflowing greenhouse and want to move them out into the elements as soon as I can.

So… When is it safe to do it and what special care should you take?

Remember, especially it the UK, it is always a compromise, they will never do as well as they would in the shelter of a greenhouse, but follow these guidelines to give your plants the best chance possible.

1/ My book has loads about temperatures, but just to summarise – If they go below about 18°c they won’t grow (some need even higher temperatures). You needn’t worry about them getting too hot. Even UK record high temperatures will make them jump for joy. Look at the forecast and judge accordingly, they can go cooler at night, but keep an eye on both daytime and night-time temperatures. For me this is, and it is the same most years, about the beginning of May through to early September.

2/ Think about bringing them indoors at night or in cold weather. They will benefit from this protection. It doesn’t matter if you put them in a dark corner, or even a garage, it is night time anyway.

3/ Try and only move established plants outside. Pot on your seedlings into their big pots but let them get established before they go outside. Tender small plants are more likely to get bashed by the wind and rain.

4/ Use big pots, these will keep moisture levels more balanced in drying winds and when the plants get bigger they won’t blow over. They also store heat during the daytime which keeps the roots warm at night.

4/ Protect them from the elements – Put them in sheltered warm spots, try and shelter them from wind as much as possible with trellis or other plants, anything to stop them being bashed.

5/ Stake the plants – Wind causes so many problems, in particular the constant swaying movement which loosens the stem at the base and tears at the roots. Also, use small sticks to support branches when the plants get bigger. Wind is your enemy.

6/ Don’t assume that rain is enough to keep them watered. I can’t emphasise this enough. Think about when you water a plant, you probably give it about 1/2 an inch at least. Very rarely do we have that amount of rain in the summer, especially on a daily basis. A light shower will get the surface wet, but it won’t reach the roots. Also, when they are kept against a wall they may be in a ‘rain shadow’; everything else nearby gets wet, but they get nothing.

7/ Too much rain can be a problem too. During we periods remove any trays from beneath pots so they aren’t sitting in water. If there is a storm forecast, then try and bring them into somewhere sheltered.

8/ Keep feeding them! Outside plants need all the help they can get, and regular feeding will keep the roots healthy and help them withstand the drying effects of wind. Use chilli plant feed or standard tomato feed.

A Miserable Chilli Plant

A fairly miserable, poorly fed and bashed chilli plant. (A deliberate experiment!)

8/ Move pots around regularly to search for slugs and snails hidden beneath. Look in the holes in the bottom of pots too. For small plants particularly this will be the biggest and most immediate threat the their existence.

9/ Holidays – If you entrust their care to a neighbour and you only have a few plants, they might get better care if you carry them round to their garden rather than making the neighbour come to you. Reward your neighbour with plenty of chillies, they might get hooked too. Alternatively consider planting them in a self watering system, more expensive, but at least it guarantees they are watered and fed for up to 2 weeks while you are away.

10/ Choose the right varieties – Be realistic, habaneros, scotch bonnets, and most of the super hot chillies need higher temperatures than our climate will give, and a longer growing season too, they really won’t do well outside unless you wait till they are fully grown, and you might not have the space for that. Stick to varieties that grow quickly or withstand harsher weather, Hungarian Wax are picked early, Bulgarian Carrot are very tough, and reasonably hot, Aji (Capsicum baccatum) varieties are also very resilient, with woody stems and small leaves. Apache F1 is nearly always foolproof as it is so quick and also compact, or for something hot and brightly coloured try Twilight.

New Chilli Seedlings

Why didn’t my chilli seeds germinate?

It is getting a little late to plant chilli seeds now, in the northern hemisphere anyway,(although there are still a few you can get away with). But there is still time to dwell on why your seeds didn’t grow, and time to learn some lessons, so here are a few reasons why your’s may not have done well.

1/ Poor quality seed. Seed that has been stored in damp or warm conditions isn’t going to germinate well, also the older seeds get the less viable they become. I still germinate seeds after a couple of years, but after 3 year or more they really don’t do well unless you have stored them in laboratory conditions of controlled temperature and humidity.

It may be you to blame, or it may be the seed seller. Reputable seed sellers should ‘germ test’ each batch of seeds before they are packaged, this involves germinating a few of them each time and working out the germination rate. If it isn’t up around 90% they should either not sell them, or at least warn you of the problem and give you extra ones to plant.

2/ Too dry  – If your seeds are allowed to dry out after you have planted them, it is likely they won’t survive. Keep the compost moist, but not too wet. If you think you could grab a fist full of it and squeeze water out then it is probably too much.

3/ Too cold – They won’t germinate at all if they spend too long below about 18°c. You will only get the best germination rates if you keep them constantly above room temperature.

4/ Too hot – A heated propagator, in direct sunlight, where the temperature might reach 50°c is going to kill of newly germinated seeds before they see the light of day, either by inhibiting germination, or baking them dry. Always try and keep your seeds warm, but don’t overdo it.

5/ Damping off – Strictly speaking this isn’t a reason for non germination, it is an affliction of seedlings, not seeds, but it is one reason why germinated shoots never make it to the surface. Damping off is simply a term used to describe rotting, when bacteria in the soil thrive because of wet conditions and lack of airflow. Think of where mould grows and you will get the idea. Usually it happens to crowded seedlings emerging from soil that is contaminated with bacteria and mould spores but it can happen to seedlings before they emerge from the soil. To guard against it, use clean new compost, not stuff that has sat in a damp shed all winter. Don’t water-log it, and don’t plant the seeds too deep, 1cm is more than enough. I generally use vermiculite to cover seeds, it is sterile and holds a little moisture but drains well.

For something more on germination times have a look at this earlier blog entry.

Newly emerged chilli seedlings

Newly emerged chilli seedlings

Chilli Seedlings - From the book 'Growing Chillies'

How cold will my chilli plants go?

We had some unseasonably cold weather in the UK recently, and where I live near the south coast of Devon frosts at the end of April are almost unheard of. But we had some all the same, and it caused a few problems. For me it wasn’t so much the night time lows, but the general cold, when the sun wasn’t out greenhouse temperatures during the day were too cool for plants to grow quickly, so everything is behind.

There were a few touch and go nights though, and towards the end of April I had just too many plants to bring indoors, so they had to run the gauntlet of some near freezing temperatures.

The lowest my max/min thermometer read was -1°c in the greenhouse, but don’t take this as definite. Have you ever browsed the range of thermometers available in a garden centre? Have a close look, last time I bought one the readings on all the thermometers on offer ranged from 18 to 21°c, and they were all hanging from the same shelf! I bought an average one, but there is no telling how accurate it really is. I suspect the temperature didn’t quite reach as low as -1°c, or if it did it wasn’t for very long, maybe only 15 minutes before dawn.

So did my plants survive? Yes, they all did, (not so the courgettes planted outside). And what does this tell us about the lowest temperatures young chilli plants can endure?

My experience tells me that as long as there is no cold wind or rain blowing directly against the plants, which means they need to be in a greenhouse not outdoors, and as long as the cold temperatures only go on for an hour or two, then the air temperature can go down to just 2 or 3°c and still recover happily, but who wants to gamble on a couple of degrees this way or that? And remember this is far from desirable, they aren’t actually growing at these temperatures, as they would if they were bottoming out at 19°c, so warmer is always better.

Another factor that can seriously jeapordise the well being of small tender plants is how quickly they warm up. Generally the soil in their posts will retain a little heat to insulate the roots. The plant might wilt slightly when it draws down fluids into the roots as a reaction against the cold. When the sun suddenly starts to warm the greenhouse then the wilting leaves can’t transpire quick enough to offset the rapidly increasing temperature and the drooping leaves shrivel. In the past I have seen chilli plants looking healthy before sun-up, but two hours later they have died. This is a particular problem where a greenhouse is sheltered from the rising sun and remains cold until later in the morning when suddenly the strong sun peeps over nearby buildings or trees and the temperature rises from nothing to 30°c in a matter of seconds, rather than a gradual warming as the sun rises. This is why instructions on constructing greenhouses always tell you to site it somewhere away from such situations.

Finally, of course, different varieties react differently, tepin, most Capsicum pubescens, (so rocoto), and many aji varieties will be slightly more tolerant than others.




8 tips on keeping your young chilli plants at the right temperature

One of the best things you can do to make sure your plants grow at optimum speed is to look after the temperature and try to give them constant warmth. In the spring time this can be difficult, but here are a few tips as to how you can do your best to keep temperatures high, and consistent.

Plants aren’t human, they don’t have feelings and moods. They are simply a load of chemicals jumbled together, and each type of plant has it’s own slightly different composition, which is why some like damp, some like dry, some like heat and some cold. High temperatures are a big part of what makes chilli plants grow, and when the temperature is right for them, they grow, and when it isn’t they don’t. Look at weeds in the hedgerows, one week nothing, next week a foot high. You want your chillies to go from an inch to a foot quickly, so let’s get the temperature right.

For optimum growth rates you should be aiming for a constant 27-31°c during the day, and slightly lower at night, say 23-26°c. At these temperatures your chilli plants will almost grow before your eyes, and maybe two or 3 times the rate of something kept at ‘room temperature’ with a bit of extra sunshine during the day.  Put simply, they will grow when the temperature is right, and stop when it isn’t, so any extra time or money you can spend on maximising this growing period will be rewarded with better results.

Chilli in black pots

  1. Firstly, and probably most importantly; remember, half the plant is roots, so soil temperature is at least as important as air temperature.
  2. A heated propagator – For germination and for young plants this is the easiest way to keep them warm. When they have germinated and are growing nicely, you can remove the lid and the warm tray will continue to keep the roots warm.
  3. Soil warming cable – For a larger number of plants, and if you can afford the luxury, then this is the best way of optimising soil temperatures to grow your plants as quickly as possible. It means you need a big sunny window if not a lovely greenhouse, with a big tray or specially constructed bench, a purpose bought warming cable, some insulation and some sand or inert substrate. Then you can thermostatically control the temperature of the roots of your plants accurately.
  4. Let sunshine get to the pot – When sunshine is hard to come by arrange your pots so they get the maximum benefit. If they are in a position where the side of the pot is exposed to direct sunlight, then the warming effects of the sun will mean the pot and therefore the roots are warmer than the surrounding air.
  5. Use black pots rather than the traditional red ones. These are often cheaper and they absorb the heat of the sun more.
  6. Bigger pots – there is no harm in potting small seedlings straight into their final big pots, the big volume of soil acts as a heat sink to keep roots warm long after the sun has disappeared. It also stops the big temperature fluctuations that small pots suffer from. Beware – if big pots are kept in a cold place and never get a chance to warm up, then the opposite will happen.
  7. Move them around! – The simplest job is sometimes the hardest as it involves time and effort. Put them in the greenhouse or the sunny window during the day and move them into a warm room at night. The more you keep them at their optimum temperature, the more time they will spend growing.
  8. Hydroponics – This is a more expensive alternative than traditional pot growing, but once you have made the initial investment of time and money the rewards will be higher with quicker growing plants, bigger plants and ultimately more chillies. Depending on your setup, the root temperature, and possibly that of the whole plant, are thermostatically controlled. Top this with the perfect nutrient mix and you will be way ahead of the competition.

Remember there is more to it than just heat, you need to juggle all of these tips with lots of lovely bright light too.




I wish plant sellers would get it right

I wish plant growers would get it right. I saw this in my local garden centre; they took the trouble to make a special label with the name Paper Lantern, but the picture, maybe some kind of Italian long sweet pepper, is almost as far from a paper lantern as you could possibly get. How misleading for new chilli growers is that?


For anyone interested in what a paper lantern really looks like, here is a picture of one.

Paper Lantern Cropped


Chilli Seeds

How long does it take for chilli seeds to germinate?

This is one of the most common questions novice growers ask; rarely are the answers detailed enough, and often they are misleading. The most common problem is when seed merchants give a very broad ballpark estimate of 2-6 weeks or something similar, covering their backs for any eventuality thereby mismanaging peoples expectations.

The reality is that most chilli seeds should germinate within 14 days, some of them much sooner. The quickest I have ever found are senor serrano, a modern commercial variety of serrano, in good conditions they will be emerging within 4 days. A lot of commercial jalapeno varieties aren’t far behind this, and I’d say the average is around 10 days across the board if conditions are perfect.

Chilli Seeds

The exceptions are often the super hot things, especially bhut jolokia and nagas, they are very erratic and often take longer, but again there are instances where they will pop up within 10 days or so, though this is less likely as they are more particular about moisture and temperature and it is more difficult to get things spot on. The more recent super hots, like Trinidad scorpions and Carolina reapers are less fussy.

The other exceptions, according to my non scientific experimentation is anything brown, by which I mean chocolate habanero, mulato, pasilla etc. There are many times where I deliberately set these to germinate next door to each other, or even in the same pot, and they have under-performed when compared to their standard relatives, e.g. mulato v ancho, or chocolate habanero v orange habanero. This is strange as ancho and habanero aren’t even the same species, but maybe the genetic variation that causes brown-ness also weakens germination, not for me to say without some proper tests.

Notwithstanding a dubious seed supply, or seed which has been poorly stored, if your seeds aren’t as quick as I have suggested above, then there is likely to be a problem with the way you are germinating them. Don’t despair, things will still happen, but be aware that your conditions probably aren’t perfect, so next time try something a bit different. You might have to buy a book to get all the details on what to do and what not to do :), at least now you know what you are aiming for.

Hoverfly laying eggs on a chilli plant

Hoverflies, Predators of Greenfly

The most commonly talked about predator of greenfly is ladybirds, you can buy them online, or collect them from around the garden, often on stinging nettles, which are themselves riddled with greenfly.

Just as effective, and just as common, if not more so, are hoverflies. The flies themselves usually feed off of plant nectar, but the larvae of many hoverfly species feed on greenfly along with other aphids, thrips and any other small insect they can get their teeth into.

I have a few more greenfly than usual in the greenhouse this year, but today I noticed that the battle has turned against them. I have left the doors wide open in the last few days in the hope that some predators might come in, even at night, which means I risk moths coming in, and that means caterpillars. Sometimes the line between good and bad is a fine one.

I discovered a new way of finding greenfly, just watch where the hover flies go. I have never watched them this closely before.

Update – For a bit more on greenfly detection have a look at this later blog entry.

Hoverfly laying eggs on a chilli plant

Hoverfly on chilli plant

This chappy (chappess actually) hovered around the plants from shoot to shoot, only stopping at the ones which had greenfly in the tips.Here you can see her sucking on a leaf, maybe one that is covered with the sweet sticky dew that the greenfly exude, this is also the stuff that ants love. I couldn’t get a picture of her next move, which was to reach in with her back end and lay an egg among the greenfly. One egg laid, then on to the next shoot. Only the shoots with a greenfly benefited from an egg, so hopefully in a day or two a tiny larvae will emerge on each and start munching. They grow quite quickly so in a few days I will have a picture of one. Watch this space.

Aji Chilli Flower November

When will my chilli plants die?

I had set aside this morning to do a little bit of pruning on a handful of plants that I would like to over-winter. In my growing chillies book there is a section on keeping plants over the winter, what temperatures to keep them at, how to prune them and when. But it isn’t an exact science, and very dependent upon autumn temperatures, where you live and where you keep your plants.

Anyway, despite the fact that we are only 5 weeks away from Christmas, the plants I want to keep, which are still in a greenhouse, in south Devon, are all still healthy and don’t yet need any pruning. Having said that, the ones I am keeping are mostly ones that I know will do well, or that I know are worth investing a bit of time and warmth in. So I have a some aji plants, a nice big piri piri, and a whopping great moruga scorpion. There are a few others which have a bit of fruit to ripen, but things like jalapeno, most of my habaneros, pimiento de padron and a few others have mostly been consigned to the compost bin.

So my thoughts turned to which plants would die first if I left them as they are. Which are the most frost tolerant? And some people might be interested in an experiment we conducted at the chilli farm many years ago. With the help of the weather we achieved some fairly accurate and interesting results. In a polytunnel containing 100 varieties we didn’t do the usual autumn cleanup, which is the way it should be done, good garden hygiene, stop the spread of disease, bla bla bla; instead we left the plants in situ, and while the temperature dropped over successive days we observed the results. This was the first cold snap of the year, so to begin with all the plants still had most of their leaves.

As the temperature inside the tunnel dropped towards freezing the first plants to succumb were the tropical ones, Capsicum chinense the habaneros and scotch bonnets, they will lose all their leaves in a single night at 1 or 2°c.

The next night the temperature dropped lower, and hit zero for the first time. At this point the ones to go are the bigger Capsicum annuum big peppers and jalapenos, especially the newer more highly bred ones.

Another day went by and overnight the temperature had reached -1°c. Now looking along the beds it was really evident which ones were survivors and which ones had suffered, but the leafless plants were interspersed with quite a few that still retained their leaves. These were mostly the Capsicum baccatum, tougher leaves and stems, originating from Andean areas where frost tolerance would be an advantage. But also the piri piri, tabasco, and strangely the Prairie Fire were still lookiing good, so the Capsicum frutescens display a lot of frost hardiness too.

Yet another day, and another degree or two of frost, and the only survivor was the tepin, a scrubby bunch of twigs, tiny tough leaves, and a very poor fruiter, but this truly wild chilli out-lived the rest; in fact this very plant lived on for four more years, until a very cold winter brought temperatures of -10°c, and that was the end of it.

So what is to be learned from this? Whatever the ‘rules’ about plant pruning and overwinter temperatures there will always be exceptions. My favourite is the piri piri, always the most loved chillies in my collection. I have said this before, but my mother has the ‘mother plant’ it is the only one she keeps now, so the seed never crosses with anything else, and I always kick off more than I need every spring. There are a lot of varieties under the piri piri banner; this is a Portuguese one, from an old ladies garden, and about midsized as they go, up to about an inch long, and they are solid bullets.

Piri Piri in a Raised Bed, November

Piri Piri in a Raised Bed, November

This picture of Piri Piri plants was taken on 12th November. It sits in a fairly sheltered south facing raised bed, which most importantly gives it good drainage so its roots aren’t sitting in claggy wet soil. The mild autumn temperatures this year do the rest, and it still flourishes albeit slowly, with ripe fruit, new fruit, and flowers.








Big Greenhouse Piri Piri Chilli

Piri Piri in the Greenhouse, November

This plant is the same variety, but inside a greenhouse, it is still going great guns, and might even survive the whole winter at this rate.








Aji Chilli Flower November

Aji Chilli Flower, November

I’m always interested to know what the real survivors are in the chilli world, so if you have any anecdotes or experiences, post them underneath for others to see.