How to grow courgettes / zucchini in containers

Courgette : Zucchini flowers

Courgettes / zucchini are productive and easy to grow in containers - and one plant will give you fruit for several weeks.  Homegrown, they are firmer, less watery and with fuller flavour than shop bought.  They do grow big and bushy and take up lots of space - for climbing alternatives see end of post. To do well they need a big pot, plenty of sun and feeding.

What size of pot?

Courgettes need big pots. 20 litres (4 gallons) is probably the smallest, 30 - 50 litres (6 - 10 gallons) is even better. An old recycling bin, a 'bag for life' or an old water tank is ideal.

How to grow courgettes / zucchini

  1. Plant seeds in small pots (1/2 to 1 litre) inside from late April to early June, and keep in a warm bright place. If on a windowsill, putting white paper or foil behind the plants will help reflect more light on to the plant.
  2. When the plant is a 4 - 6 inches (10 - 15cm tall) start moving it outside on warm sunny days. This will help acclimatise it to the outdoors (gardeners call it 'hardening off'). Remember to bring it in again at night. Young plants do not like wind so keep your plant inside on windy as well as cold days.
  3. Once the plant has filled the pot (when you see roots coming out of the bottom holes) it is time to move it into a bigger pot. If the threat of frost has passed (usually late May / early June in much of UK), you can move it outside into its final pot. If possible, avoid doing this on a windy or very hot day. Water well after moving it. (If it is too soon for the plant to go outside, you will need to move it into a slightly bigger pot inside.)

    This courgette was started in this one litre pot - and is now ready to move into its final, big pot. This courgette was started in this one litre pot - and is now ready to move into its final, big pot.
      
  4. You can grow courgettes in old, used potting mix / compost (they are not too fussy) but you need to mix in fertiliser first. Worm compost (if you have any) and / or a good handful of general purpose fertiliser like blood fish and bone will do nicely.
  5. Courgettes are hungry beasts - for water, food and sun. Put in a sunny place, (six hours plus a day), and keep well watered. Feed with liquid tomato feed once a week once it starts flowering.
  6. Courgettes produce male flowers (no fruits behind them) and female flowers (with fruits behind them). Sometimes they produce male flowers only for a few weeks before producing female flowers. The flowers are a delicacy and can be eaten stuffed or added to risottos or salads.

    Male and female courgette flowers.
  7. Picking the fruits small (and at their most tasty) will encourage the plant to produce more fruits.
  8. Courgettes will usually grow into BIG plants, and can start to overshadow  plants nearby. To reduce this problem, it's ok to remove a few of the largest, oldest leaves without damaging the plant.

    A few large leaves can be cut back to reduce overshadowing of neighbours. It grows big and bushy! A few large leaves can be cut back to reduce overshadowing of neighbours.

Common Problems

The most common problem in courgettes is mildew, a fungus that looks like white dust on the surface. It won't usually kill the plant but it will reduce its productivity. Removing the worst infected leaves can help slow the spread. Good watering can also help reduce the chance of plants getting mildew (it thrives in dry conditions).

Mildew is a common problem - regular watering can help delay its onset. Mildew is a common problem - regular watering can help delay its onset.

Climbing courgettes?

Because courgettes are big and bushy, they can take up a lot of room in a small space. Some websites show how they can be encouraged to climb. I've tried this and it's not as easy as it looks. An alternative solution is to grow tromba or tromboncino squash. This has a flavour similar to courgettes and is a vigorous climber. It's great for making the most of vertical spaces and also fun to grow. The squash can be eaten small like courgettes or left to grow a metre long!

Tromba or tromboncino squash is an excellent climbing alternative to courgettes. Grow it the same way, and provide string or trellis for it climb up. Tromba or tromboncino squash is an excellent climbing alternative to courgettes. Grow it the same way, and provide string or trellis for it climb up.

Your turn

I’d love to hear your tips for growing courgettes / zucchini in containers in the comments – and any varieties that you particularly like to grow?

30 comments

Pix
 

Hi Mark, thanks for all the info, guidance and encouragement. I think I have solved the slug problems with my salad greens. I raised a grow-bag tray on bricks and sandwich between them an over hanging layer of copper mesh from builders merchant. My dahlias and hostas are still nibbled But the romaines, cos and pick-and-come-again are all thriving.
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Reg
 

I am trying Yolanda courgettes this year as they are compact and mildew resistant. So far they are looking good but the fruits are quite small. Good job I have 5 plants instead of the usual 2 Zuccini. I like your website and look forward to your tips even though I have been gardening for many years. Best wishes Reg
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Mark Ridsdill Smith
 

Many thanks for sharing that, do let us know at the end of the season how you think Yolanda performs. It is always invaluable to learn from each others experience - especially as most of us only have space to try one or two varieties each year.
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Emily Findlay
 

I have tried 2 years in a row to grow courgettes in window boxes in my South facing 2nd floor flat but the plants only seem to grow a foot wide and then falter. could this just be the wind they don't like? Is there any other veg a bit more wind tolerant? Thanks, Emily
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Simone Micallef
 

Ha!! I think you ve solved why I only have beautiful flowers so far...Must be patient....and enjoy the flowers....too beautiful to cut! xxxxsimone
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Mark Ridsdill Smith
 

Courgettes need big pots (ideally 20 litres minimum) so it might be that your window boxes are a little on the small side and the courgettes run out of energy? That said, courgettes also do not like strong winds, particularly when they are small and young, so that might also be a factor. Here's a link to a post on wind I wrote - it includes some ideas for more wind tolerant plants.https://www.verticalveg.org.uk/growing-in-the-wind/ But unless your home is in a bad wind tunnel (which is possible) courgettes should normally do OK so my first guess is pot size.
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Nicola
 

I’m intrigued about growing them in a bag for life?! I would’ve thought the sides would sink. Any tips on that? I’ve got a courgette I need to pot up and that would be a great and more eco friendly option for me than buying another pot. Thanks!
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Adrian
 

Hi. Thanks for the guidance and inspiration! After many, many years, I've finally cleared out my balcony/patio. I now have quite a few plants growing in pots: two kinds of squash, plus cucumber, tomato, aubergine, courgette, and herbs and calendula. I'd just like to ask about feeding courgettes. Do you advise stopping feeds when the plant flowers? And would a tomato fertilizer be good or would a courgette need something a bit different? In addition to giving the courgette tomato fertilizer, I leaf-sprayed my in-flower plant with liquid seaweed. Do you think I should continue with the seaweed? At the moment, the plant is in a small pot. With this fast-growing plant, I should pot on into as large a pot as I have space for, yes? Looking forward to your thoughts...
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Mark Ridsdill Smith
 

Start feeding when the plants flowers and continue once a week or so while it is fruiting -tomato feed is perfect. Continuing with the seaweed is also a good idea. And, yes, put it in a large pot, at least 20 litres.
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Adrian
 

Thanks! Got some reasonably priced 35 litre pots from Amazon and repotted the courgette today. Gave the roots a seaweed spray to lessen the shock. One or two spherical fruits (Geode variety) at the moment. I’m expecting lots more and I think the plant’s going to become a giant!
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Reg
 

Further to my comment of 21 June, my Yolanda courgettes are now doing well. The fruits are a good size - about 8ins (20cms) - and do not grow too big. 3 plants are doing so well that we have made chutney and given some to the neighbours.
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Joanna
 

I decided this year to grow courgettes in pots. As i never did before i was wondering if there is a particular pot material that I should use or can i plant in my large ceramic pots? Also what is the best size for it? Many thanks
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Mark Ridsdill Smith
 

A large container is best for containers - minimum 20 litres but 30, 40 or even 50 litres is better. Small terracotta pots dry out rather quickly but a large one should be fine. Large plastic containers have the benefit of being light and easier to move - but terracotta is a nicer material to grow in.
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joanna
 

Thank you for the guidance.
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Simone Micallef
 

last summer I had mainly male flowers....Any ideas how to get female ones that then obviously fruit? many thanks Simone
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Kevin Christie
 

Growing two types of courgettes standard and 8 ball. It's my first try, have grown supermarket garlic, very nice, This time acquired garlic from seed merchants.
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Nan
 

Congratulations for your great post. I came here looking for guidance on my courgettes. I started them from seeds in a windowsill. The weather has not been good enough to move them outside, and they are flowering!! In pots far smaller than mugs!! I am puzzled, as they are so young and small. Is this bad? Are they going to stop growing? Should I halt the transplant plant outside?
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Mark Ridsdill Smith
 

Sometimes plants flower early when they get stressed- it might be that the pots are now a bit too small for them. Try moving them into slightly larger pots with some fresh compost and they may still be ok. You could also sow a few more as backup, just in case.
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Nan
 

Thanks for your swift reply! I will follow your advice.
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ann newcombe
 

Do courgettes need staking?
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Lesley Liggins
 

My courgettes have small spiral like tentacles on like peas have does that mean they are climbers and will have to be grown vertically Thanks lesley
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Mark Ridsdill Smith
 

do you know what variety they are?
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Mark Ridsdill Smith
 

Normally they form a bushy plant that isn't really suited to staking.
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ann newcombe
 

Thanks. They're in large pots now & fruiting already. Thirsty little things aren't they!
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Kaifa
 

I’d advise cutting the male flowers would encourage(signal) the plant to direct its energy stores towards producing female flowers which require more energy. Retain 1-2 male flowers (stamen) for fertilisation. It’s not uncommon for a plant to put out male flowers initially as it requires much less effort, while it establishes itself.
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Kaifa
 

I used large PP(BPA-free, safe plastic) rollerboxes which was great because, I could then roll and change their position around my veranda, so the plant could receive max sunlight during the day or put them under the roof cover when there was heavy rain.
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Shelagh Troy
 

Hi I want to grow courgettes in a raised wooden planter would this be sufficient ?
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Mark Ridsdill Smith
 

As long as the planter is at least 20 litres in volume it should be fine.
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Valeria
 

I love planting courgettes, but so far we've eaten precious little of them (over the last 6 years), as mildew usually kills our plants before they get to produce anything. We live in Spain, just outside Barcelona, and hot, dry conditions are the norm these days, starting in March. I will give them another go in a few large containers I've found beside the bins (they are communal here, not one for every house). As an anecdote, last summer an enormous pumkin plant grew spontaneously in an empty plot. It covered about 20 m2! We ate the male flowers in various preparations until well into November, until the first frost killed it. Every neighbour in the area had a chance to get some green pumkins or even the larger, orange ones. They weren't delicious - in fact they were rather tasteless, but they could be breaded and fried or used to bulk up a stir fry- , unlike the flowers which nobody else ate, but they were free and I think that alone made all of us quite happy.

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Mark Ridsdill Smith
Staff
 

I love your story of the rogue pumpkins! And so glad you made good use of the flowers - a delicacy. Yes, sadly, courgettes are more prone to mildew if they dry out. You could maybe also try to rig up some sort of simple DIY irrigation, too - perhaps a plastic bottle full of water with a small hole in the top. There are instructions online. 

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