How to grow giant pumpkins

Picture by Julian Meade

At some time in our lives most of us have seen or touched a monstrous-sized pumpkin. It may have been at a county fair or a farm, but we were in awe and we wondered what it would be like to grow one of our very own.

This could be your year. Early spring is the time to start planning and gathering top-secret information on how to grow your own record-breaking pumpkins. Maybe this year, it’ll be your pumpkin that makes mouths drop and eyes pop. 

Genetics play the biggest role

The seed’s genetic code is the most important thing you need to have. Starting off with pumpkin seeds that have a genetic pre-disposition to huge-ness is key.

The seeds that grow the largest, in fact the only type of pumpkin to win the world’s record every year since 1979, are ‘Dill’s Atlantic Giant’. So the first thing you’re going to want to do is purchase some Atlantic Giant pumpkin seeds either from a seed catalog or a local nursery. 

Start early and prepare the bed

To take advantage of as much growing season as you can, it’s best to start the pumpkin seeds indoors a few weeks before the last frost date. While your seeds are germinating indoors, prepare the pumpkin bed outdoors. Introduce as much compost and composted manure that you can to the soil of the bed. The pumpkins will need all the nutrients they can get to grow to monstrous proportions, so you’ll want  to have as much organic matter as possible. If you would like to test the soil pH, ideally it should be between 6.5 – 6.8. 

Help with pollination

Plant your pumpkin seedlings in the prepared bed and water regularly for about 8-10 weeks. The plants should begin blooming around that time. There are female flowers and male flowers. The female flowers are the ones with the little pumpkin behind the blossom. The male flowers don't have the little pumpkin, which makes this part rather simple.

The sooner a pumpkin forms and begins to grow, the longer it’ll have to become the large pumpkin of your dreams. Ideally, this would be before July 10th as these beefy guys can gain up to 25 pounds a day! You don’t wasn’t to lose any day by waiting for natural pollinating.

So, your best bet is to hand-pollinate the flowers yourself. On early morning go out to the patch and choose an open male flower. Pick it off the fines and pull off the outer petals. What you’ll have left is the stamen with fresh pollen on it. Find an open female flower and lightly brush the inside of the female flower with the stamen of the male flower. 

Choose the contenders

When your pumpkins start to form, look for the ones that are very round and long. Also choose the ones that are growing the fastest. Measure around the largest part of the pumpkins to help you choose the keeprers. These are the ones that will become the biggest in your pumpkin patch.

At that point, you’re going to have to decide which to keep (keep only a few) and cut of the rest. It’s brutal, but necessary if you’re trying for a prize-sized pumpkin. Also, keep the end of the vines pruned to about 8-10 feet beyond the pumpkins so the growth energy is spent on the pumpkin size.

The position of the vines as related to the pumpkin’s stem is very important. As it gets heavier and heavier, if the stem is at the wrong angle, the pumpkin will snap off. You want the stem to be perpendicular to the vine it’s growing on. While you do want to fertilize your pumpkins once or twice a week, avoid over-fertilizing them. If pumpkins are fertilized too much, it’s possible that they could pull away from the vines and in effect – blow up!

When we grew our Atlantic Giants, we placed a big, thin board (like plywood) underneath the pumpkins so they wouldn’t rot on the side that was against the soil. At the end of the growing season, you just may find that you have a contender for a “largest pumpkin” contest. You may want to check out the Safeway World Championship Pumpkin Weigh-Off in Half Moon Bay, California.