Beyond the Pond: Growing Giant Pumpkins

Published on February 24, 2024

Giant Pumpkin in truck

Why grow giant pumpkins? I ask myself this every year. I started gardening more than 30 years ago, about the same time I built my first pond. At first, it was to have some pumpkins around Halloween and take pictures with the kids. I didn’t want to go out and buy a big pumpkin. Back then, it was hard to find a pumpkin 100 pounds or more. They were few and far in between — and also expensive!

I decided I would just grow one. How hard could it be? (Pretty damn hard, actually.) As it turns out, only a couple of varieties are genetically capable of that. I found Dills Atlantic giant pumpkin seeds, a strain patented in 1979 by Howard Dill, “The Pumpkin King.” He broke the world record in 1980 with a 459-pound pumpkin. I figured I would write him a letter asking for growing tips or possibly some seeds from his pumpkins.

Aqua UV

There were barely any computers or internet back then. If you wanted seeds, you had to write letters to growers requesting them. Howard sent seeds and some tips. I was excited and wanted more information. I looked for books and found How-to Grow World Class Giant Pumpkins by Don Langevin 1993. If I read that book once, I read it a hundred times. In 1994, with my seeds and book in hand, I set out to grow something big!

Need for Seed

pumpkin seedlings to full growth
The seedlings get potted up a couple of times before going into the temporary greenhouse. The plant itself grows fast — up to 1 foot a day in all directions. Huge
leaves are like solar panels for the pumpkin’s growth.

Seed selection is one of the biggest things that can make or break a season. Back in the ‘90s, there was a limited selection of seeds and pumpkin growers growing them. Today, growers can choose from thousands of giant pumpkin seeds available. More people involve themselves in the pumpkin growing hobby every year. It’s all about trying to find the right seed genetically to grow the big one.

Most competitive growers choose “proven” seeds. This means they have a track record of growing pumpkins between 1,500 – 2,000 pounds or more. At auction, some of these seeds will sell for hundreds of dollars. You can also opt for a rookie seed. Rookie seeds come from a great lineage or weighed heavy the year it was grown. First-year seeds can typically be found for free if you contact the grower.

All seeds have a hierarchical tree, or a lineage dating back years with pumpkins that were crossed to produce it. A grower can look at the hierarchy tree and see what traits the pumpkin they are growing will have, including color, wall thickness and weight.

I start my seeds in mid-April. After sprouting, seeds may be potted a couple of times. The roots grow very fast, and you want to avoid the plant becoming root bound. I target the first week in May for planting in the pumpkin patch. The weather can still be cool and wet. I put up mini greenhouses that are 8 by 10 feet. This keeps the soil and air temperatures warmer, while protecting small plants from the elements.

Patch Work

Prior to the plants going into the patch, I have my soil tested. This is a must to know what you are starting with. Otherwise, you are starting the season blind. You will find out how much, or how little major nutrients are in the soil. Cation exchange capacity (CEC), pH, organic content and micronutrients are also key. The lab will help you decipher the results. You can then adjust your fertilization program for the season based on the results. Basically, you need to become a scientist of your soil. I add compost every year to keep my soil fertile and healthy.

I have two pumpkin patches — one at my house and one at our shop — that are 30 by 30 feet each. One plant will encompass this area; it will support just one pumpkin. Most competitive growers give 800 to 1,000 square feet per plant. The plant will root and feed wherever the vines grow.

I try to pollinate the pumpkin in mid-June. The plant has both male and female flowers. All pumpkins are female. Pollination is not left up to the bees! I select male flowers the night before and cover them with plastic cups. I tie the female flowers shut to ensure that the cross will be pure and not contaminated by insects. It also keeps the flowers dry in case of rain. I try to use, if available, two to three male flowers to one female. Male flowers are more abundant than females.

I might just get a couple of good chances at pollinating before July 4, and I want the actual pumpkin to grow in the 100-day range. So, mid-June is crucial for pollination. We harvest at the end of September for the pumpkin weigh-off.

Tip the Scale

Pumpkin weigh-in
This 1,807 ½-lb. pumpkin is the biggest I’ve grown to date.

In 1996, I grew a pumpkin that weighed 477 pounds. That was a large pumpkin back then! It took all season to get that size. Today, if you want to be competitive at the weigh off, it needs to weigh that or more after 30 days of pollination. Nothing grows faster than a giant pumpkin, I’m convinced of that!

This is how you get hooked into the hobby. At day 30, the pumpkin should be doing at least 30 pounds per day as a benchmark. The 1,807 ½-pound pumpkin I grew this year hit 50 pounds a day at its peak.

Some growers use digital platform scales. For now, I still rely on flexible tape measures and reference charts to calculate daily gains and final weight. Pumpkins are around 90% water. So, you need to water a lot. Every pumpkin patch has a different soil composition. I ended up watering about 100 gallons a day or more during peak pumpkin growth. At my home patch, I pump warmer, nutrient-rich water from my pond or bog and stored it in large containers. Small amounts of fertilizer are added every time I water.

Don’t just grab the miracle grow off the shelf and go at it. Too much chemical fertilizer at once is the worst thing you can put on the plant. The mixture is sprayed overhead once or twice a day. Too much water or rain can be problematic. You need to find the right balance of rain, water and fertilizer, and then dial it in.

Insecticides and fungicides need to be used throughout the season as well. Insects and disease can ruin the season fast if you don’t stay on top of it. I inspect the plants daily for both. I spray various fungicides and insecticides once a week throughout the season.

Petal to the Metal

Several things need to happen to give your pumpkin room for rapid expansion. I often lay a bed of sand down and belt material that is used in paper mills. Both help keep the bottom of the pumpkin dry and protect it from mice (or anything else that wants to burrow in from the bottom). Vines are pruned and trimmed away to allow for future growth. I cover the small pumpkins with laundry baskets to protect them from squirrels and raccoons. I have lost early pumpkins to both if they are not covered.

As the pumpkins grow, I erect small tents to cover them. The tents keep the pumpkins shaded from the sun and dry from rain. Sheets and blankets can also be used for protection. As the pumpkin grows, the vine growth will slow down. The pumpkin will demand most of the energy the plant can offer. The plant itself is misted with cool water or covered with shade cloth on hot days. Leaves can wilt and burn up on hot days. If they do, they are not producing efficiently. Every leaf counts for pound producing power.

Measuring the Pumpkins

pumpkin patch
An overview of the patch — it’s at about full size to support the beast’s pollination time.

I begin measuring the pumpkins’ circumference 10 days after pollination. I measure my pumpkins in the morning. They put on the majority of weight at night. In the daytime, the plant makes sugars through photosynthesis and stores them at night. Weight benchmarks are important at day 20 and 30. You should be able to tell if you have a big one around these dates by comparing to your past records or published 2,000-pound pumpkin growth rates.

This is the most exciting and stressful time for pumpkin growing. I have cut pumpkins off the vine at this time that don’t measure up. I have also had pumpkins split and look as if they shattered in the morning. Sometimes they grow too fast for their own good!

In July and August, most of the weight will be put on. I hope for a warm and drier September. A cool and a wet ending to the season does not help the pumpkin put on the weight it needs for possibly a personal best or winning the weigh-off.

The Big Reveal

Scarry giant pumpkin
Halloween is always fun around our house. I have some pumpkins professionally carved and others hacked up in a scary way.

Harvest day is one day prior to the weigh-off. It is a holiday, or an easy workday is scheduled. My employees, custom pallets, lifting rigs, skid steers, trucks and a good plan are all needed for loading and unloading the pumpkins.

If I’m lucky I have two to load. There are no guarantees in pumpkin growing. All could be lost at this point. So, it is somewhat of a victory getting a pumpkin that is not damaged to the scale. Growing a personal best, not necessarily winning the weigh-off, is most important to me. Pumpkins will be disqualified or marked as “exhibition only” if they are cracked or damaged to the cavity of the pumpkin. All pumpkins are inspected at the weigh-off for these defects.

At our weigh-offs we typically have 15 to 20 pumpkins. It’s also a time to reconnect with other growers. We talk about the trials and tribulations of the season — what worked or didn’t work. I have known some pumpkin growers almost 30 years and have become great friends. I have also seen a lot of growers come and go. It’s a tough hobby with a regimented schedule. It will drive growers away if they have no success or get burned out.

After the weigh-off, my pumpkins are set up as a display in front of my house. Other growers will sell them off. You can expect to pay $1 or more per pound for a giant pumpkin if you can find a grower willing to part with theirs. I get joy out of having them carved and displayed. Hundreds of people stop by to take pictures and ask questions. Halloween is a pretty crazy time at our house! The fire department stopped by one year because of all the fog my fog machine had generated and all people who had gathered. (They stayed and handed out candy.)

Growing Plans for 2024

Every year I still ask myself if I should grow again. When I grew my 159-pound pumpkin in 1994, I got hooked. Then I wanted to grow to 500, 1,000, 1,500 … and now 2,000 pounds is sight in for 2024. So, I will grow on until I reach at least 2,000 pounds!

If you would like to try growing in 2024, contact me at George@gemponds.com. I can get you more growing tips and seeds to get you started in the hobby. Read more Beyond the Pond features here.

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