Life-cycle of a Giant Pumpkin

The timeline of a giant pumpkins growth

How long does it take to grow a giant pumpkin?

It can take anywhere from 140 – 160 days to grow a giant pumpkin, the general rule is 60 days of plant growth and 90 days of fruit growth. This can vary between sites due to climate, aspect, soil condition, seed genetics and a whole bunch of different factors. But transplanting your seedling in late October (Labour Weekend here in NZ) will give you a pumpkin ready in March/April the following year.

How to Work Out When to Start

To help work backwards to make sure you have enough time to grow for your event check out, a great tool to help you work out dates in the future or in the past.

When a giant pumpkin is in it’s biggest growth phase it can be putting on as much as 20 + Kg’s a day at its peak. This is pretty mind-blowing when you think about it, one seed that only weighs a few grams can grow and produce a fruit that is in the hundreds of kilos.

Life-Cycle of a Giant Pumpkin

Please Note:  This is a general guide to a giant pumpkin’s growth.  Everyone’s will be slightly different, due to seed, location, weather, water etc.

Day 1

Planting Seeds Indoors

Starting your giant pumpkin seeds early on in pots is the best option, early October is a good time to do this.

Learn About Seed Starting



Plant Extras Just in Case

It always pays to have backup seeds, you never know how the start of the season will go.


Day 9 - 10

Seeds Start Germinating

If all goes well and you have started your seeds properly, they should be germinating by now.  Some seeds can be slow starters.


Day 20

First True Leaf will Appear

The first true leaf will appear in the middle of the seedling.  Between the 2


Day 22 - 25

Transplant to Patch

Hardening off your seedling is an important step to a successful transplant out to the patch.

Learn About Transplanting


Day 25 - 36

Early Season Protection

Keeping your seedling protected from wind and cold is very important.

Learn About Early Season Protection


Day 51

Pest Control

Keeping on top of any pests at the early stage of growth is important.

Learn About Pest Control


Day 55-65


Pollination and the position of your pumpkin on the vine are things you need to think about.

Learn About Pollination


Day 75

Phosphate Fertiliser

A change in fertiliser to maximise growth of the pumpkin is advised around this time.

Learn About Fertilising


Day 80


Protect your pumpkin from the harsh sun will allow it grow bigger.

Learn About Shade


Day 81


Consistent watering will help your thirsty pumpkin plant put on better growth.

Learn About Watering


Day 82


These may be required to help control things like powdery mildew.

Learn About Fungicides


Day 96


Lots of growth in the pumpkin will occur around this time.


Day 100

Skin Hardens and Darkens

The pumpkins skin will start to harden, and possibly begin to darken.


Day 156

Growth Slows

By this time the growth has slowed right down, not much more will happen.


Day 160

Moving your Pumpkin

It’s time to get your pumpkin out of the patch and off to a weigh-off.

Learn About Moving Your Pumpkin