How to: Grow giant pumpkins, Part 1

by Lala

The giant pumpkin project started at the end of September 2014. After reading up on hugelkultur we set up a raised bed using some of its concepts. The bed didn’t turn out quite as I’d envisioned, but it has been working wonderfully, as evidenced by the happy pumpkins growing so fast there. I may do a detailed post on hugelkultur (German, meaning hill culture) in future.

Preparing the bed

The soil was very poor when we moved in, and because pumpkins thrive on soil with rich organic matter, a lot of work was required. I chose an area in full sun for the raised bed. It is a semi circle, sectioned off by short wooden poles (the kind often used for edging). It is about 5 metres long on the straight side. We dug 3 or 4 trenches and placed thick branches from trees we had pruned earlier in the year, in there. Great carbon sequestration with this method. This was followed by a thick layer of our own garden compost, then manure and topsoil. The top layer was a mulch of mostly intact leaf litter from the compost heap, in order to suppress weeds, retain moisture and eventually to enrich the soil when it breaks down. We watered it and let it rest for a week or so before planting anything.

The raised bed, mulched with a lot of compost and leaves to enrich the soil and slow evaporation.

The raised bed, mulched with leaf litter from the compost heap.

Preparing the pumpkin seeds for planting

The Dill's Atlantic Giant and Big Max pumpkin seeds were ordered online and arrived quickly via courier.

The Dill’s Atlantic Giant and Big Max pumpkin seeds were ordered online and arrived quickly via courier.

The seeds were purchased from Seeds for Africa, whom I can highly recommend. Delivery was fast and it was via courier right to my door, so I didn’t have to worry about them sitting at the post office for weeks. They even put some herb, chilli and veggie seeds in the package as freebies. I soaked the seeds in lukewarm water for 24 hours. I don’t recall if I filed down the edges. This prep is recommended by the giant pumpkin experts in the USA, on their forums. On 2 October 2014, I planted the seeds directly into the soil, where I wanted them to grow. The five Dill’s Atlantic Giants went into the raised bed and the Big Max pumpkins were planted between other plants in different areas of the yard. I had 100% germination rate after about a week and a half or two weeks. Very impressed with that.

The full grown Dill’s Atlantic Giants start to tip the scales at around 90kgs (200lbs) if the are on the small side and can get to over 450kgs (1000lbs). Those monsters are usually from specially selected seed that is grown by the competition level pumpkin growers. As a first timer, I will be happy if mine reach 90kg. The thrill of growing a pumpkin bigger than me will be a hoot! The Big Max giant pumpkinvariety is smaller, but it can get over 45kgs, which is still very impressive.

The first true leaf emerging, on a Dill's Atlantic Giant pumpkin sprout.

The first true leaf emerging, on a Dill’s Atlantic Giant pumpkin sprout.

The plants were fed with organic fertilisers including fish emulsion and Neutrog Bounce Back pellets every couple of weeks. They needed regular watering during the extreme heat of late spring in Gauteng. There was a very long dry spell this year before the first proper Highveld storms. By 22 December 2014 the Atlantic Giant vines were starting to fill up the bed and climb all over the place, including onto the young Oom Sarel peach tree and roses nearby.

Two giant pumpkin vines are pictured here, on 22 December 2014.

Two giant pumpkin vines are pictured here, on 22 December 2014.

After the pic above was taken, the raised bed was weeded, then mulched with our own garden compost and store bought, cow manure. Our chickens’ manure was not ready yet. There was a lot of rain in mid to late December. The heat and humidity seemed to cause a growth spurt.

Progress and more pictures will follow in Part 2.

Part 2
Part 3
Part 4

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