How to Grow a Large Pumpkin

Some pumpkin varieties naturally grow larger than others.

Pumpkins come in a wide variety of shapes, sizes and colors. The most visually impressive pumpkins tend to be giant pumpkins, growing several times larger than standard pumpkins, and weighing up to 40 lbs. or more. Though giant varieties of pumpkin grow large naturally, those who want to grow especially large pumpkins can increase the size of their giant pumpkins even more by ensuring they grow in conditions favorable to producing large gourds.

Instructions

1. Start with the right pumpkin seeds, ensuring they're seeds for a jumbo giant pumpkin variety instead of a standard or pie pumpkin. If using commercially bought seeds, the packaging will state whether they are giant pumpkin seeds or not.

2. Plant the seeds indoors in individual peat pots at the end of April or early May to allow ample time for germination and growth.

3. Transplant the pumpkin plants to a prepared garden patch outdoors two weeks after they begin germinating; this should occur in mid to late May or early June at the latest. Build up a small hill of soil around each plant with the roots 1 to 1 inches deep, spacing them at least 12.5 feet apart in all directions, to give the plants a minimum of 150 square feet of development room.

4. Apply liquid fertilizer to the ground surrounding the pumpkin vines. Use a high-phosphorous fertilizer the first time you fertilize, to encourage root growth, then switch to a balanced fertilizer that provides equal amounts of nutrients.

5. Thin out the pumpkin patch as the vines grow, removing those plants that grow slowly or produce small vines. This gives the remaining plants more room to grow and also helps ensure that only the strongest plants produce pumpkins.

6. Pinch off the first two or three flowers that appear on each vine. Removing the flowers gives the pumpkin vines more time to grow leaves before focusing on the growing of pumpkin gourds -- resulting in more leaf area available for photosynthesis once the pumpkins start to grow.

7. Allow a single pumpkin to develop on each vine, then remove all of the other flowers on the vine so that additional pumpkins don't start to grow. Lift the vine near the pumpkin periodically to ensure roots and smaller vines don't develop, which will hold the vine to the ground and restrict the pumpkin's growth.

8. Water whenever the soil around the pumpkin vine becomes dry, as large amounts of water are needed to produce large pumpkins. Continue tending the pumpkins until they reach the size you desire or when they attain a deep and uniform color with a hard rind.

Tips & Warnings

• Keep water off the leaves when watering your pumpkins to avoid the development of mildew that often damages or kills the pumpkin vine.

References

• University of Illinois Extension: Pumpkins and More -- Questions and Answers
• University of Illinois Extension: Watch Your Garden Grow -- Pumpkin
• Ohio State University Extension: Fact Sheet -- Growing Giant Pumpkins In The Home Garden; David A. Mangione