How to Grow Pumpkins

Guide Note Halloween is just one of the many reasons people want to grow pumpkins. They also make a great fall decoration, are great in pies and fun to carve. A good way to get started early on fall festivities is to learn how to grow your own pumpkins.

Table of Contents

• Introduction
• Step 1: Choosing a Variety
• Step 2: Where to Plant
• Step 3: How to Plant
• Step 4: Pumpkin Care
• Step 5: Dealing with Problems
• Step 6: Harvesting
• Step 7: Growing Giant Pumpkins
• Conclusion
• References

Growing Pumpkin Tips

1. Pumpkins belong to three different species: Cucurbita pepo, Cucurbita maxima and Cucurbita moschata.
2. The cultivar of pumpkin planted will determine how much space it needs.
3. Planting pumpkins too close together can cause problems with disease.
4. Pumpkin size is determined more by its type than by gardening conditions.
5. The smallest pumpkin weighs less than a pound; the largest can weigh more than a 1,000 pounds.

Newest How To Guides

Tips on dealing with difficult people

Great ideas for mixed drinks

Beat the cold of winter by making the perfect cup of hot chocolate

Need to save money? Learn how to spend less on food

All the information you need to make the digital TV switch

• by Darcy Logan

Introduction

• Pumpkins have been grown somewhere in the world since 8750 B.C. Today, there are over 100 varieties of edible pumpkins, although not everybody agrees what a pumpkin is.¹ The term "pumpkin" refer more to the description of the fruit. It is not a member of one species, but selections from three different species: Cucurbita pepo, Cucurbita maxima and Cucurbita moschata. These species include many varieties of squash and zucchini as well as pumpkins. Not that the species really matters, since they all have similar requirements and growing habits.

Step 1: Choosing a Variety of Pumpkin

• 

  Pumpkins come in more shapes and sizes than your traditional Halloween fare. (Creative Commons photo by Tambako the Jaguar)
  Your first step is to select the type of pumpkin you want to grow. The type you select will help determine the space needed, when to plant and harvest and how to plant.

1. Miniature pumpkins are all varieties of C. pepo and will weigh up to a pound. Plant two feet apart with rows six to eight feet apart.²
2. Small pumpkins weigh between two to eight pounds. Plant two feet apart with four to six feet between rows.³
3. Medium pumpkins weigh between eight to 15 pounds. Plant three feet apart with four to six feet between rows.³
4. Large pumpkins weigh between 15 to 25 pounds. Plant four feet apart with six to seven feet between rows.³
5. Extra large pumpkins weigh between 20 to 40 pounds. Plant four feet apart with seven to nine feet between rows.³
6. Jumbo pumpkins weigh more than 30 pounds. Plant five to six feet apart with 10 to 12 feet between rows or more.³

• • For more information, check out Mahalo's guide on How to Choose a Pumpkin Variety.

Step 2: Decide Where to Plant

• For best results, pumpkins need to be planted in a sunny location with fertile, well-draining soil. They are a warm-season crop and can be easily damaged by frost.⁴

1. Pumpkins require full sunlight.⁵
2. Do not plant pumpkins in the same place two years in a row. Instead, rotate them with non-cucurbit crops to help control disease.
3. Pumpkins need plenty of moisture, especially during planting.³
4. Soil needs to drain well as pumpkins will not do well in soil that remains soggy.
5. Pumpkins are moderately tolerant of acid soils but have a preferred pH range of 6.0 to 6.5.
6. Heavier soils, such as clay, can be improved by adding organic matter such as peat, compost or rotted manure.
7. In northern areas, light, sandy soils are preferred because they are quicker to warm up during the spring.

Step 3: How to Plant Pumpkins

• For the best pumpkins, you need to plant them correctly. This will help minimize problems with disease and give you the best quality pumpkins when you need them.

When to Plant

1. Plant pumpkins once the soil has warmed to 65°F and all danger of frost has passed.⁶
2. If you want pumpkins for Halloween, plant them between late May and early July. You will want to plant them earlier in northern locations and later in southern regions.⁴

Depth and Spacing

1. Pumpkin seeds should be planted one inch deep.⁴ However, if you live in a drier area, you can plant them up to 1.75 inches deep to keep them in a moisture zone.⁷
2. Spacing will depend on the cultivar and size of pumpkin you are growing. Below is the minimum guidelines. If you are growing larger pumpkins, they may need more space. See Step 1 for more information.
   1. 

      Make sure to space out your pumpkins so they have room to grow comfortably. (Creative Commons photo by Kyle Flood)
      Vining pumpkins should be planted four to five seeds per hill. Each hill should be five to six feet apart, with rows being 10 to 15 feet apart. Once plants are well established, thin each hill to the best two to three plants.⁴
   2. Semi-bush pumpkins should be planted four to five seeds per hill. Each hill should be four feet apart with eight feet between rows. Once plants are well established, thin each hill to the best two to three plants.⁴
   3. Bush pumpkins should be planted one to two seeds per foot of row and thinned to a single plant every three feet once they are established. Rows should be at least four to six feet apart.⁴
   4. Miniature pumpkins should be planted one inch deep, with two to three seeds every 2 feet apart. Rows need to be 6 to 8 feet apart.²

How to Plant

1. Remove all residue of any previous crops before planting.³
2. Apply four to six cups per 100 square feet of either 16-16-8 or 10-10-10 fertilizer to the soil before planting.⁶
3. If seeds are not colored, you need to dust them with thiram or captan before planting to help prevent disease.⁵
4. Seeds are planted one to two inches deep in mounds or hills about eight to ten inches high. Form the hill by creating a three to six inch deep trench around each mound.⁵ Once seedlings have sprouted and have two to three leaves, thin them out based on the guidelines listed above under Depth and Spacing.
5. If you are transplanting pumpkins, take care not to damage the roots.⁶

Step 4: Pumpkin Care

• Pumpkins do not need extensive care. However, if you want the best quality pumpkins, there are a few things you can do to help ensure this.

Water

1. Watering should be done deeply and infrequently.⁶
2. Apply between one to inches of water each week, making sure that it soaks into the soil about 6 to 8 inches deep.^{6 5}
3. This amount should be reduced as the fruit ripens.⁶ Water in the morning or early afternoon.⁵

Fertilizer

1. Once runners have developed, sidedress with an additional nitrogen (34-0-0) fertilizer.
2. Use approximately one to two tablespoons per plant or mound at least six inches from the plant.^{6 8}

Mulches

1. Mulching will help conserve soil moisture and reduce weed growth.
2. Using a black plastic mulch has the added benefit of helping to warm the soil allowing for earlier planting and maturity.
3. If you decide to use an organic mulch, do not add until the soil is warmer than 75°F.⁶

Row Covers

1. The use of hotcaps, plastic tunnels or fabric covers can help you protect your young plants from cool weather and will enhance growth.
2. Remove the row covers when the pumpkin starts to flower or temperature exceeds 90°F.⁶

Pollination

1. Pumpkins require the use of insects for pollination. Without them, pumpkins experience poor fruit shape and excessive blossom drops.⁸
2. Avoid using insecticides during the first four weeks of flowering in order to prevent killing of bees that are working the flowers.³

Step 5: Dealing with Problems

• Three problems that any gardener will have is how to control weeds, disease and pests. Pumpkin growers will find some particular problems with them that are common to pumpkins.

Weeds

1. Weedy gardens will not only make harvesting difficult, but increase the likelihood of disease due to poor air circulation.³
2. You can control weeds with mulch or by applying a pre-emergence herbicide after seeding.⁸

Don't let pests cast a shadow over your pumpkin harvest. (Creative Commons photo by Greg Younger)

Disease

1. Common diseases for pumpkins include bacterial wilt, plectosporium blight, powdery mildew, downy mildew, botrytis blight and anthracnose.
2. Controlling these diseases require selecting resistant cultivar, rotating locations and proper site selection.³

Pests

• Pumpkins can have trouble with insects at any time during the season.³ There are three major insects that can bother pumpkins:

1. Aphid: Aphids are green or black insects that feed on the bottom of the leaves, causing them to crinkle or curl. Use insecticidal soaps to control.⁶
2. Cucumber Beetle: Cucumber beetles are yellow-green beetles with black stripes and spots that feed on the leaves. Their larvae eat the roots and tunnel through the stems. Apply insecticides at the first sign.⁶
3. Squash Bug: Squash bugs are large brownish-black insects that will suck the sap from the leaves and vines causing the plant to wilt. They are difficult to control with chemicals and will require removal by hand.³

Step 6: Harvesting

1. Pumpkins will mature about 45 to 55 days after flowering.⁶
2. You can tell they are ready to harvest because they are fully colored, the vine has begun to die back or the rind is hard and resistant to scratches with your fingernail.
3. Harvest mature pumpkins with the three to five inches of stem attached and store them where they won't freeze.^{3 6}
4. You can reduce the chances of postharvest rot by washing or dipping your pumpkins a 10 percent solution of chlorine bleach and storing them in a dry, cool place.⁸
5. For best results, pumpkins should be cured. Curing is done by storing the pumpkins at a high temperature (between 75°F to 80°F). This can be done by cutting them from the vine and allow them to stay in the field.³

Step 7: Growing Giant Pumpkins

• 

  Growing freakishly huge pumpkins will be slightly more complex. (Creative Commons photo by Jackie)
  If you have a desire to grow a giant pumpkin, expect to spend a lot of time and garden space to the task. Giant pumpkins need at least 150 square feet per plant. You will need to select one of the jumbo varieties listed above and plant early in June.⁴ Allow only one fruit to develop on each plant. With proper fertilization and insect control, your pumpkin might hit the 1,100-pound mark.⁸

• For more information, check out one of the following sites:

1. Oregon State University: How to Grow a Monster Pumpkin
2. Ohio State University: Growing Giant Pumpkins In The Home Garden
3. Backyard Gardner: 10 Steps to a Giant Pumpkin
4. Backyard Gardner: World Class Giant Pumpkin Home Page
5. Plantideas.com: How To Grow Large Pumpkins  

Conclusion

• After the harvest, you will face one of your biggest dilemmas: what to do with all those pumpkins. It can be difficult to decide between pumpkin pie, pumpkin bars, pumpkin bread, pumpkin cheescake, pumpkin cookies, pumpkin cupcakes, pumpkin fudge, pumpkin rolls, pumpkin soup or one of the many other pumpkin recipes out there.

Subscribe to Mahalo's Weekly How To Email Newsletter

• Get our best How To tips and ideas in your inbox each week
• Email
  

References for How to Grow Pumpkins

1. ↑ Lindsay Sterling: What's a Pumpkin?
2. ↑ ^{2.0 2.1} University of Illinois Extension: Watch Your Garden Grow: Pumpkins
3. ↑ ^{3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13} Virginia Cooperative Extension: Specialty Crop Profile: Pumpkins
4. ↑ ^{4.0 4.1 4.2 4.3 4.4 4.5 4.6} University of Illinois Extension: Pumpkins and More: Growing Pumpkins
5. ↑ ^{5.0 5.1 5.2 5.3 5.4} Purdue University: Growing Cucumbers, Melons, Squash, Pumpkins and Gourds  
6. ↑ ^{6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 6.12} Utah State University Extension: Pumpkins in the Garden  
7. ↑ The Pumpkin Patch: Everything You Ever Wanted To Know About Pumpkins!
8. ↑ ^{8.0 8.1 8.2 8.3 8.4} North Carolina Cooperative Extension Service: Growing Pumpkins and Winter Squash