Growing Giant Pumpkins in Melbourne 16

Growing Giant Pumpkins in Melbourne

Beni Meier holds the heaviest pumpkin world record.

The biggest pumpkins come from the variety called ‘ATLANTIC GIANT’. The current world record for an Atlantic Giant pumpkin is held by Beni Meier from Switzerland, with a 2,323 pound Pumpkin, which is a whopping 1054 kg!

How to grow Giant Pumpkins in  Melbourne

Dale Oliver holds the Giant Pumpkin Australian Record

The current Australian Record is held by Dale Oliver, with an impressive 743kg Pumpkin.

There are hundreds of websites and books on how to grow giant pumpkins. Most of these guides are suited to growing pumpkins in Northern America, rather than here in Australia. We’ve taken the principles of Giant Pumpkin Growing and distilled it down into a simple to follow guide for Temperate Australian Conditions.



Good seed, good soil, good luck and a little hard work are needed to grow an Atlantic Giant Pumpkin 150 kg or larger.

The good luck plays a big part when growing Giant Pumpkins in temperate Australia, as our variable weather plays a huge role in determining success or failure.


Your patch should receive as much full sun as possible.

Optimally, you will need 50 square metres (approx. 7 x 7 m), to grow a giant pumpkin, but many have been grown in much smaller spaces.

Soil preparation is the most important thing you can do to help in growing a giant pumpkin. Soil preparation should be done from late autumn, into winter (or even very early spring). Add lots of organic matter, compost and manure, to the general planting area and dig it over.

If you are planting your pumpkins early (late September, or early October) you’ll need to protect them from the frost. Make a mini hoop house over your patch about a week before transplanting. This will warm up the soil and protect the plant when it grows. Use clear plastic sheeting to cover it.



Choosing the right seed is important for How to grow Giant Pumpkins in Melbourne

One of the most important considerations when growing giant pumpkins is choosing the right seed.

An important decision when trying to grow a giant pumpkin is seed selection. Choosing your pumpkin seed can be like choosing a racehorse. Seed suppliers in Australia are somewhat limited, so you might have to go with whatever seed you can source. If you want to get really serious, you might like to try importing some seeds from North America. But, remember Australia has very strict quarantine laws, so make sure you research Customs regulations first.



In Melbourne, planting times for pumpkins are generally late October, avoiding frost damage. Recently, backyard tomato growing has seen a trend in starting earlier, and this could also be the case with pumpkins.

In North America, where the winters are colder, they propagate their seeds inside and transplant after the danger of frost has passed. You could try starting you seedlings off in August/Early September, in a hothouse and then transplant them later. But, be warned, these plants grow very quickly, so don’t start them too early, or they’ll take over your hot house.



If you want to take the lazy approach (which we use) plant your seed directly into the ground. Hill up a low flat mound of soil, about 1 metre in diameter and create a depression in the top (for watering). Plant your seed in the depression and water well. Keep the soil damp, but not saturated until the seed has germinated. Letting the soil get too wet may cause the seed to rot.

Growing Atlantic Giant Pumpkin Seedlings Melbourne

You can sow your giant pumpkins seeds early, in pots. Just make sure you re-pot them or plant them out before the roots start coming out the bottom.

On the other hand, if you’re really keen, you could start your seed off earlier (August/September) in a pot of seed raising mix. Keep it indoors, somewhere warm (but not hot). A close watch is needed, as the plant will grow quickly. It will be need to be either re-potted into something larger, or transplanted before the roots start growing out of the hole in the bottom of the pot. Use a liquid fertiliser when transplanting the seedling. Ideally use something containing seaweed which helps to promote root growth.



Your plant should start to send out its first vine within 2-3 weeks, depending on the temperature. This vine is called the main vine. As the plant grows it will produce side vines off the main vine, called secondary vines. The pattern of growth is naturally in the shape of a stylized Christmas tree with the longest secondary vines closest to the beginning of where the plant starts (called the stump) and getting progressively shorter as the vine gets longer. These secondary vines are where the plant gets most of its food for the fruit. Nurture both the main and secondary vines.

Later the plant will produce tertiary vines that grow off of the secondary vines. Usually growers trim these off so more energy can go into growing the fruit.



Keep your pumpkin vine well watered. The vines themselves will be putting down roots. To assist with producing the extra roots, cover parts of the vine in places with soil (just not on the leaves!). The soil should stay nice and damp at all times.



Weekly feeding is important if you are trying to grow a truly massive pumpkin. Every pumpkin grower seems to swear by their own specific formulations. The general rule is” Lots of Fertilizer, with the, right stuff, at the right time.” Start with a high nitrogen formula in the spring. Apply a high phosphorous fertilizer in advance of the blooming/fruit set stage. Finally, switch to a high potassium formula, for fruit growth and plant health.

In North America, there are many companies that sell specific fertilizers aimed at growing giant pumpkins. If you’re really keen you could source them out on Google and try importing them!



Many types of insects (and slugs) will damage your pumpkin vine and the fruit itself, especially where it is in contact with the ground. We recommend you use garlic sprays as a deterrent rather than harsh insecticides or chemicals.

Many pest hide in weeds and weeds suck up precious water so be sure to keep your pumpkin patch weed free.



Just like race horse owners, serious giant pumpkin growers like to keep track of their plant lineages.  To ensure the genetic lines, most growers hand pollinate so that they know who the mother plant and father plant are. This may be because they are looking for certain attributes such as bigger pumpkins, heavier pumpkins, more orange pumpkins, different colored pumpkins, and specific shapes.

If hand pollinating, it’s a good idea to pollinate all the female blossoms until you decide which one(s) you want to keep on the plant. Then once decided, cull all unwanted female blossoms and baby pumpkins, so the energy will go into the selected ones. Eventually you should cull your fruit down to only one or two fruits per plant.

If you choose to only grow one giant pumpkin plant and are not growing any other squash in the Curcubita Maxima family and don’t care about the genetic line for later seed distribution, then the bees can pollinate.


How to grow giant pumpkins in Melbourne

Male flowers (left) do not have the baby pumpkin present under the flower like the females do (right)


Positioning the fruit is important, as you don’t want the fruit to grow on top of the vine that is providing nutrition Optimal positioning of your pumpkin is perpendicular (90 degrees) to the vine but is not always possible. Start positioning the pumpkin relative to the vine when it is little. Gently move the pumpkin a few centimetres a day away from the vine until it will be clear of it when it gets bigger. This will reduce stem stress when it starts to really gain weight. Be very careful when moving, as it can snap or crack easily.



Your pumpkin stem should be free of any tension so it can grow upwards with the pumpkin. Cut any taproots that may have formed on either side of the pumpkin so the vine will be free from the ground at that point.



Build a shade structure with a tarp, or put shade cloth on your pumpkin, to protect it from sunburn and premature aging in the hot sun. If the skin stays soft the pumpkin will grow faster than when it hardens. If the pumpkins’ skin starts to harden it may cause the pumpkin to stop growing in size and start ripening.



Put 10 cm of sand under your pumpkin when it gets to be about the size of a soccer ball to keep it dry. Spread it out to a 1.5 metre circle to allow for the pumpkin to grow. If you wait too long, the pumpkin will be difficult to pick up and do this. Use two people to lift the pumpkin. Alternatively you could try growing your giant pumpkin on a large sheet of polystyrene.



How to grow atlantic giant pumpkins in Melbourne

Burying the pumpkin vines promotes root growth to provide further nutrients for pumpkin growth.

Train the secondary vines at right angles to the main vine to keep it in the stylized Christmas tree shape. When the vines start to get about 2 metres long, dig a 5 to 10 cm trench and bury all vines (but not the leaves) with soil as they grow out. This protects the vines from pests as well as promotes a secondary root system to really fuel the pumpkins growth. Allow about half a metre of open vine at the growing end unburied. Trim tertiary vines off of the secondary vines.



Growth will slow tremendously later in the season as the temperatures cool in the day and night. Put shade cloth and blankets over your plant when the temperatures fall below 15 degrees C at night.


When your pumpkin has stopped growing and is ready for harvest, cut it from the vine. Then you’ll need some heavy lifting machinery with lots of care to move it. You can even buy Pumpkin Tarps and Pumpkin Slings online to help you get your pumpkin to a weigh-off!


Remember to keep us updated with your giant pumpkin growing progress by sharing photos on the Leaf, Root & Fruit Facebook Page.

Looking to grow a giant vegetable but limited on space? Why not have a go at growing a Zucchini Tromboncino instead?

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16 thoughts on “Growing Giant Pumpkins in Melbourne

  • Kyleen Partridge

    Hi there guys, we have been addicted to growing big pumpkins since 2009 and have taken out awards and wins at the local kootingal big pumpkin festival a few times – are looking to source some new seed genetics for the upcoming season – any help advice for imported stock would be welcomed! What does seedstock from Dale Oliver’s winner go for?

    We respect the price attached to good genetics and just love growing the biggest we can!! we have developed a good performer with our original seedstock both from the Pumpkin Lady and a South African import but always on the hunt to experiment and look at other lines to keep it exciting.

    Look forward to your feedback cheers Kyleen

    • Leaf, Root & Fruit Post author

      Hi Kyleen,

      Thanks for your interest in our blog. Sounds like you take your giant pumpkin growing pretty seriously! I don’t think we have anything you’d be interested in at this stage. We’re experimenting with some seed stock supplied by the guys behind the Summerland Pumpkin Competition. They have seeds available from the competition’s winner from last year (367kg), plus other seeds from a vigorous orange pumpkin at 265kg and another at 197kg. They also have Watermelon seed from the same stock that grew a massive 82kg watermelon! You can get in touch with them through their Facebook page:

      If you’ve got any seed stock that you think our growing community might be interested in trying out, please get in touch.

      Best of luck for the upcoming growing season!

      Leaf, Root & Fruit

  • Eva Connellan

    Hi, I have a question about growing pumpkin, just normal pumpkins, not giant ones:

    I saw my brother-in-law pulling out his pumpkin vines a couple of months ago, so I took the roots and planted in my backyard. Now the plant is growing very healthily, but no sign of flowers or buds. I am wondering if planting from roots is not good, Does it have to be from seeds? Thank you for your expert advice.

    • Leaf, Root & Fruit Post author

      Hi Eva,

      I’ve never tried growing pumpkins from root cuttings, but I’m excited to hear that it has worked for you. Many plants are regulated by environmental conditions. This could potentially be the case with pumpkins and they may be waiting for warmer weather, longer (or shorter) days to induce flowering. Please keep us updated on progress. I would expect that the plant will set flowers at some point soon and would be very keen to hear from you on how they do.

      Good Luck and Happy Gardening!


      • Eva Connellan

        Dear Duncan,

        Thank you for your response to my pumpkin growing from last year’s root question. So far it looks healthy, but still no flower. Will keep you updated, hopefully see it’s flowering soon.
        Best wishes,



    Good Afternoon,
    Is the pumpkin ok for people to eat or only fit for the chooks? I work in a Primary School and if it is edible, we would like to make all sorts of things from the pumpkin flesh.
    Also, how do we tell when the pumpkin is ripe?

    Mant thanks.

    • Leaf, Root & Fruit Post author

      Hi Rosie,

      I presume you are referring specifically to the Atlantic Giant pumpkin. The answer is, yes it is edible. However, the flesh is usually fairly lacking in flavour. I’d much prefer to each a tasty butternut or Queensland blue!

      The pumpkin’s skin will go quite hard when ripe. The vine nearby to it will start t die back and the pumpkin will have a hollow sound when (gently) slapped or knocked.

      Good Luck and Happy Gardening!


  • bill howard

    i am a new grower of giant pumpkins. last year was my first try. and i ended up withtwo good pumpkins. i took one off to give the other a chance to get bigger. however at appx 90klos the pumpkin burst. how can i prevent this from happening in future.
    all advice welcomed.

    • Leaf, Root & Fruit Post author

      Hi Bill,

      That sounds very frustrating, and one that we’ve also encountered. My guess would be inconsistent watering (or too much water, too quickly). Better luck next year!


    • Leaf, Root & Fruit Post author

      Hi Jeany,

      There’s nothing wrong with the giant pumpkins. They just lack flavour and have a coarse texture compared with the more common eating varieties.

      Good Luck & Happy Gardening!


  • John Lewis

    I have a question about pollination.
    My plant is growing vigourously but I was bit late planting, I think, and although it is starting to produce male and female flowers, I wonder if I should nip them all off until the plant is much bigger and screaming to reproduce itself – and then start the hand-pollinating.

    • Leaf, Root & Fruit Post author

      Hi John,

      Depends on if you are trying to grow giant pumpkins or not. If you are after giant pumpkins then yes, that’s a great idea. If you just want to grow lots of tasty pumpkins then I just let them do their thing. Occasionally I hand pollinate, but usually the bees have it under control anyway!

      Hope that helps


  • Meg

    Hi Duncan & Team.
    I attended a workshop you ran Duncan, at Ashburton Food First over a year back – really enjoyed it, thank you.

    I am the Convenor of Garfield Community Garden, we are running a comp of Growing a Giant Pumpkin.
    I googled “how to grow a giant pumpkin” happy to say your info from past competitions came up – it’s great information, easy to read & understand.
    I normally ask permission first to use such information, but it was a rushed time. I have acknowledged Leaf Root & Fruit on the handout sheet.
    We will have a weigh in day late February approx, would love to share the winning pumpkins with you.
    Kind Regards
    Meg Platte

  • Ghada

    Thanks a lot for the info that provide for us.
    I’m new for giant pumpkin grower and with your knowledge I think I will rich my goal
    New member