Hot chillies!


Helen Simpson, from the Mushroom Shed, tells you all you need to know about growing chillies. She has also written articles about growing basil, brassicas, coriander, cucurbits, garlic, ginger & turmeric, mint, rhubarb, strawberries, tomatoes and lesser known herbs.

Additional material from Guy’s tips: capsicums, chillies and eggplants.

Capsicums, chillies and eggplants are perennial but short-lived, typically living for around three years. But, and here’s the main point of this little article, they are frost tender and are typically killed off by the Melbourne Winter. So, if you want to get full value from your capsicum, chilli and eggplant plants, you need to grow them in pots and put those pots in a warm place (e.g. a greenhouse) during Winter. If you have some and they are outside, now is the time to move them to a warmer place (it would have been even better if you had done this before the latest cold spell!).

chilliAnyone who has tasted or handled a hot chilli will be familiar with their stimulant effects – increased perspiration, burning sensation in the mouth, running nose and eyes and laxative effect – dare I go any further.

These sensations vary with the type of chilli and are due to the amount of the chemical compound ‘capsaicin’ contained in the chilli. This compound varies from negligible in the standard capsicum to a significant amount in the very hottest chillies.

Chillies and capsicums all belong to the Capsicum genus, which contains several different species and are native to Central and South America. Numerous varieties exist – some pointy and small, others round, oval and fleshy and some look like miniature hats (e.g. the Emperors Hat or Scotch Bonnet). Colours include green, yellow, red, purple, orange, chocolate and black.

How hot is a chilli?

Chillies are generally measured in heat units using the Scoville Scale, which was developed in 1912 by Wilbur Scoville. The heat units are related to the amount of capsaicin in the chilli.

For example (and depending on your reference source), the Cayenne and Rocoto Chillies have Scoville heat units of around 35,000, the Habanero around 300,000, the Trinidad Scorpion and Naga (ghost) chilli 800,000 to 1,000,000 or higher. Wikipedia puts the Carolina Reaper chilli at around 1,600,000 to 2,200,000 heat units.

Milder chillies include the Jalapeno (2,500 to 8,000). The humble capsicum is neutral.

Some of you may have heard of the Padron chilli, of which 1 in 10 are reported to be extremely hot and the rest not so. However I’ve heard varying reports on the authenticity of the 1 in 10 probability – some experimenters reporting that they are all very hot.

Growing chillies

Chillies can be started from seed. However, as the seed can burn, care should be taken and thin plastic gloves worn. Start the seeds indoors in a small punnet or pot in October/November and transplant outdoors only when weather is consistently warm – usually early December.

Chillies generally only thrive in hot, sunny weather, so in Melbourne they have a limited growing season and are usually grown as annuals. For this reason, you may prefer to begin with a small chilli plant rather than seed, to get a head start.

With care and management, chillies grown in pots can have their season extended by bringing the pot up on a sunny veranda or placing in a greenhouse when the weather starts to cool.

The Rocoto (or Manzana) chilli is one exception. Whilst severe or successive frosts can damage the plant, it usually recovers sufficiently to grow even bigger the next year. Eventually it will be the size of a large bush and you may have to cut it back with a pair of large clippers to deter its sprawling habit. It will most likely produce more chillies than you can use. Take care – the chillies from the Rocoto can be very hot.


Around late summer, fruit starts to form. Depending on the type of chilli, it is usually green, before ripening to its final colour which may be red, purple, black, orange, yellow etc. It can be picked and used green, however will be hotter if you wait until it ripens. Fruit may be on the bush right into winter.

Some varieties lend themselves to drying e.g. Cayenne or Birdseye chillies. They can be strung up in bunches. The larger, fleshy chillies are not as successfully dried like this, so are best used fairly quickly.

Common varieties

For those people seeking out the hottest chilli available, try the Naga (or ghost) chilli, Trinidad Scorpion, or Carolina Reaper (if you can find it here). But beware – they are extremely hot. Other hot chillies going down the scale of heat are the Scotch Bonnet, Habanero or Tepin, and then Thai, Birdseye, Rocoto and Cayenne.

For those seeking a milder chilli, try the Jalapeno or Emperors Hat – the Emperors Hat is also a chilli that can survive a Melbourne winter if you are lucky.

Chilli heat management

If you have eaten a chilli that is too hot, milk or yoghurt helps to relieve the burning sensation. It is reported that water tends to just spread the heat, rather than relieve it. Care should be taken handling chillies as the heat from the juice will spread onto anything you touch.

And finally …

Being a strong irritant, capsicum spray is used by the Australian Police Force.

  43 Responses to “Hot chillies!”

  1. Hi Helen
    Firstly, thanks for the great site and advice. I am in Melbourne and am growing a Carolina Reaper from seed. I have nurtured my plant from seed in a pot, persisted through yellowing leaves and finally have flowers…but they kept dropping, and again have nurtured it to where I have finally got 6 chillies forming with flowers still dropping and many more at bud stage. It is early March 2024, I have the pot in a brightly shaded morning to lunch spot but early evening full sun to avoid the torture of midday heat. This has worked and I water now twice per day on warm days. Will the chillies turn ripe red this late in the season? Am I chasing a lost cause? Should I sacrifice some of the flowers and pinch them off? I am praying to get even one useable fruit after this effort.

    • Hi Matt,

      It sounds like you are doing things right. There is still time for any fruit to ripen to red. And, anyway, the green fruit are perfectly edible. Don’t bother sacrificing and of the flowers.

  2. Hi I am in Melbourne and I have overwintered a long hot cayenne in its first year. It started shooting from the bare stems about two weeks ago which are only around 5mm long at the moment, but is producing flower buds rather than leaves. It did this as a seedling last year too, seeming to want to focus on flower production rather than growing stems and leaves. What do I do in this situation please?

    • Hi Roger,

      It sounds like your plant could be a bit stressed, so is trying to reproduce quickly by growing flowers.

      Remedies are fresh potting mix and place in bigger pot or place in the garden where it’s roots can spread out.

      Regards, Helen

  3. Hi
    I live in Seaford. I have quite a lot of Joes long cayenne (p.s. these are great), Jalapeño and Habanero. They have been left on the bush, which I guess means that they won’t ripen. Is it worth picking them and drying the seeds and re-plant (I got the plants from Bunnings)?

    Your thought’s would be appreciated



    • Hi Andrew,

      You can try saving the seeds but seeds from unripe chillies generally have very poor germination rates.

  4. I have two chilli plants, one scorpion butch and naga. I am getting flowers but no fruit and the flowers fall off. Any suggestions please?

    • Hi Mahesh,

      The most common reason for this is heat waves, where the plant gets stressed and drops its flowers. Other reasons can be: it’s in a pot that’s too small, and again gets stressed, or the flowers haven’t been pollinated. If the pot is too small, there will likely be other signs, such the leaves will be turning yellow.

      Regards, Helen

  5. I’ve been growing from seed for 4 years now in Melbourne. I bought one of those tiny 4ft greenhouses from Bunnings.
    I start the seeds indoors on a sunny window shelf in jiffy pods on the last week of August. Buy the end of September, once they are 5-8cm tall, I transfer into the smallest black pots and arrange on a tray close together in the greenhouse that gets direct sun from 7am-12pm and then gradually size up the pots every month. By the end of October, all of them are out of the greenhouse and in the open. I currently still have about 9 plants that are full of chillies.

    The Black Scorpions are nearly finished for the season and I’ll cut those back ready for spring. I love them and eat them on cheese crackers every day. My Jalapeno has finished for the season but the Lilac Cayenne is still full of fruit and changing colour. The Rocoto Aji, as others have said, is still going strong with about a dozen large pods on it. My Bolivian Rainbows are all full of pods just turning red now. They were planted later in the season though, around October.

    Some of my plants have taken two seasons to fruit, such as the Naga Viper which is one insane chilli flavour and heat profile. It grew very little the first season and then this year exploded with late season growth.

    This year I will cull the Bolivians and try out a whole range of super hot ghost varieties.

    It’s a lot of fun.
    Also, to combat aphids, I found a layer of woodchips seemed to stop them, I just sprayed them off each day with water.

    • Hi my name is Michael. I have purchased some chilli seeds and I want to start my own chilli patch because of my love for chillies. Can you please give me a few tips how to plant my chilli when they arrive and when it’s the right time to plant the chilli and what I will need to start? I thank you for your time.

      • Hi Michael,

        Plant your seeds in August or September in seed trays out of the cold (e.g. in a greenhouse or indoors). Transplant into the ground or into pots when 15cm tall. Because chillies are small plants, I grow them in pots.

      • Thanks for the info I will just that

  6. Hi!

    I have 2 established chilli plants that I have had for 2 years. In winter I cut them all the way back, this has meant the following year twice as many chillis grew and the chillis were much bigger. It’s May now and my chilli plant is still covered in green chillis and I’m waiting for them to ripen for harvest then I will cut the plant back again for winter.

    Is this normal to have green chillis in May? I have no idea what I am doing. Should I be cutting my plants back? They seem to like it.


    • Hi Lana,

      It was such a strange Summer weatherwise that all sorts of plants seem to have got a bit confused. I don’t think that your chillies will ripen any further so I would harvest them and then cut back and shelter your plants for winter as normal.

  7. I have had manzano chillies give to me, can I grow these from seed ?

  8. Hi

    I have some Caysen chillies planted and its going really well but they have been green for weeks. Will they turn red on their own? I am in Melbourne and wondering if climate has something to do with it.

    • Hi Daniel,

      Yes, they should turn red on their own. Be patient – it is still early in the season.

      • Hey Guy,

        I sowed a few Thai red chilli seeds a couple of months back and that have all grown to about a foot tall and seem to still be growing happily.
        When can I expect them to grow any chillies?

  9. Hi Helen,

    I have been growing a chili plant at my desk while working from home in Melbourne (it gets sunlight through the window). It grew well during spring and has fruited already – around 10-12 chilies. All the guides I’ve read say that they fruit in Summer and to then prune them ready for the winter. As summer has yet to arrive, I’m not sure whether to prune it yet? I guess the plant thinks it’s summer because it’s inside where the air temp is warm due to the heater etc.


  10. Hi there. I recently purchased various chilli plants from Bunnings (first time grower) I live a few hours west of Melbourne so the weather is very similar. I’m wondering when is the best time to transfer the partially grown plants to full time outside? And is growing them in individual large pots a good idea? Thanks in advance,


    • Hi Nick,

      You can transfer them at any time after they have their second set of leaves (i.e. their first set of true leaves). They do well in pots but the bigger the pot the better.

      • Thanks for the response Guy, I can’t wait to see if we get anything from them in the months to come. If not, will be a fun learning experience. Any other tips for a beginner with ready made plants?

        • You’re welcome, Nick.

          As I said, the bigger the pot the better. For chillies, I use pots with a 30cm diameter. Chillies are actually perennials which live for 2-3 years but they get killed off by the Melbourne Winter so, if they are in pots, you can put them somewhere warmer over Winter and take them out again the following year.

          Also, some chilli plants don’t flower until late summer, so be patient.

  11. Do you need a licence in certain states to grow certain plants?

  12. Hi Helen,

    I’m back recently from Peru where we did a cooking class in Lima. Aji Amarillo is the staple of Peruvian cuisine but almost impossible to find in Melbourne (other than preserved or paste) so I’ve had some seeds mailed to me. Now I’m extremely stressed about not stuffing up in my foray into growing chillies. There’s a little label on the packet that says “Sow Sp-Su, 5mm deep in equal mix of river sand, med coarse perlite, peat moss/coco coir & fine compost/worm casting. SOIL TEMP 18-20C MUST. Emerge 10-30d. Harvest after 90d.” It’s the beginning of November now so I need to get my skates on. The specificity of the instructions has caused my levels of anxiety to rise even more however haha. The guy at the local nursery who professes to be a soil expert said that I’d be fine with just standard seed raising mix. I’ve no idea how I go about measuring soil temperature. Can you give me any further tips here to make my dreams of growing aji amarillo true?

    • I should probably be a bit more specific. As seedlings how far apart should I place seeds (2-3 per hole yes) and how often and how much should I water them?

      • Hi Jason

        Did you aji manage to survive? I bought a seedling in June and its size has managed to stay exactly the same 6 months after. Hoping they grow faster now that summer is almost here.

    • Hi Jason,

      I agree with your local nursery guy – standard seed raising mix should be fine. Yes, the soil does need to be warm to raise chilli seeds – you can measure via a thermometer if you get really keen, but generally just find the warmest spot you can. To create a warm environment, raise seedlings inside the house in a small punnet or pot (not direct sunlight, as it will fry the seedlings when they start to emerge) – if you have a bottom heating mat all the better, but not necessary.

      Keep seed raising mix moist, but not soggy. Once seedlings emerge, start giving them sun during the day and grow to around 6cm in the punnet, then transfer to their final ‘home’ – outside (larger pot is best, but you can also do directly in the garden – sunny position) – protect from snails, slugs, possums etc.

      As seedlings, a few cm apart is fine but, when larger, one per pot, or about 30 cm apart if planted in a row. Watering depends on the type of day – probably every day on really hot days, maybe every 2nd day if not so hot. The aim is to not let them dry out, or have them with soggy roots.

      Regards, Helen

      • Thanks for the tips on growing aji Amarillo chillies. I have just bought seeds to try and grow the chillies for my Peruvian friend who despairs that she can’t cook using fresh chilli in Australia.

  13. Chilies freeze well and can be added to casseroles and curries throughout the year.

  14. Hi Helen thanks for this post!

    Last season I planted before summer came around and ended up five plants with healthy green leaves but they did not produce any fruit. Do you have any suggestions as to why this happened? I did add seasol but it did not help.

    • Hi Stefan,

      Chilli plants can be slow to grow and sometimes the fruit doesn’t appear until well into autumn. One suggestion is to try planting a few weeks earlier this year, keeping the plants indoors if nights are still cold until warmer weather arrives. Otherwise, see if you can keep your plants through winter (this will involve protecting them in a warm spot) so the plant is well established when summer comes again.

  15. Hi – I moved into a house with two large chilli plants in the garden. It’s a cold winter but both of the plants (one is a birdseye and the other looks like a long chilli – red and green) are still producing plenty of chillis. They are both looking really sad though. They are planted in a garden bed so I can’t bring them in. What should I do to help them?

    • Hi Sandy, assuming they are too big to dig carefully around and uproot and place in a pot, leaving them as is will be the best option. If they have survived the winter so far, they will probably continue to do so – they will look sad until Spring when they will start to sprout again. You could try wrapping some protection around them on frosty nights (take off in the morning). If you like the chillies, I’d get the seeds out of the chillies and plant the seeds in a pot in November. That way, you can grow some in a pot, in case you ever lose the ones in the garden. Regards, Helen.

  16. Hello, I planted an Indian chilli plant in my backyard (Melbourne). This chilli has medium heat, but some animal/ bird eaten all the chillies, including leaves and soft branches, in the night. Any suggestions how I could to protect my chilli plant from animals/birds? Thanks.

    • Hi Vibs, it is probably a possum that has eaten it. The only reliable way of protecting plants at night is by netting, unfortunately.

      Regards, Helen

  17. I want to grow chilli’s that are not too hot for making sweet chilli sauce. What type do you recommend?

    • Hi Juliet,

      I’d recommend the Jalapeno, and also scale down the amount of chilli you put in the sauce if you want it milder. Regards, Helen

  18. Hi,
    More of a question than a comment if i may. Can chillies be grown throughout the year in a greenhouse environment? I have managed to grow garlic in pots this way in August and i am hoping for success when i plant them out in April….as i said, “hoping”
    Best Regards,

    • Hi Elliot,

      You may be able to keep chilli plants alive in a greenhouse over winter in Melbourne, however it’s likely they will lose their leaves and won’t produce chillies. If the plants survive the winter, they will start growing and producing leaves again in Spring – so you will get a ‘head start’ on chilli plants started from seed in Spring.

      If you want a chilli plant that will go through winter without a greenhouse, try the Rocoto chilli. It will generally get beaten back by the frost, but will revive again in Spring. Beware – it turns into a very large bush!


      (Note: garlic is a winter plant, that does best out in the cold. The cold weather forms the bulbs. Plant early April, and harvest early December.)

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