Herbaceous Vine

Pumpkin

USDA Zone: 3a-11b
Lifecycle: Annual
Mature Size: 1-3 ft. tall, vine spread of 3-20 ft.
Native Region: Oaxaca Highlands (Central America)
Sunlight Requirements: 6-8 hours per day

Care

Whether growing them for pie or jack-o-lanterns, pumpkin plant care is much like other gourds. They require a minimum of six hours of direct sunlight per day (or 12-14 hours of indirect sunlight). Pumpkins also need well-draining soil and about an inch of water a week. Water the plants deeply, but avoid the leaves to reduce disease risk. Some pumpkin varieties climb if you give them a trellis or other support, helping manage smaller growing spaces.

Pests and disease concerns are similar to squash and cucumbers. Watch for signs of aphids, squash bugs, stink bugs, vine borers, downy mildew, anthracnose and blossom-end rot. Proper care, mulching and cleaning up debris will reduce the chances of these hazards.

Seeding

Pumpkins thrive in soil temperatures from 65 to 95 degrees, making them a prime summer and southern crop. For northern regions, starting the seeds indoors gives you the necessary 3-4 months of growing time. Sow seeds 1-2 inches deep in starter mix with the seeds on their sides. Place one seed per small pot or tray cell. With warm temperatures and consistently moist soil, the seeds will likely germinate within a week. At this point, move them to a sunny location. Seedlings are ready to transplant when they have two or three true leaves.

Planting and Potting

Wait until the soil reaches 65 degrees before planting or transplanting pumpkins. You can plant seeds 6-12 inches apart in rows separated by eight feet or group seeds in hills four feet apart. The hill method warms the soil up faster and improves drainage. For row planting, thin small seedlings to a spacing of 18-36 inches. Put pumpkins near the edge of the garden to keep the vines away from other plants. Containers must be at least 20 gallons and 18 inches deep to support pumpkins, and you should plant smaller varieties with high-quality potting soil.

Feeding

No creature gets big without eating a lot, and the same goes for pumpkins. Add compost or a balanced, slow-release fertilizer when preparing your planting spot. When the pumpkin plants reach a foot tall, fertilize every 2-4 weeks with a high-nitrogen formula for leaf and vine growth. Change to a high-phosphorus fertilizer when blooming starts for better fruit development. Soil testing will help you determine the exact formula and how often to apply it.

Winterizing

Pumpkins are annual plants and will not survive the winter, especially in colder climates. The main concern is that, since letting the pumpkins grow longer produces better flavor, you may need to protect them from earlier-than-expected fall frosts. Do so by adding more mulch and a frost cloth, blanket or other insulating covering.

Harvesting and Pruning

There are two ways to prune pumpkins. Cutting away female flowers, which swell underneath the bloom, during early flowering stages will produce more pumpkins that are smaller. To grow giant pumpkins, let three or four develop per vine and remove any subsequent flowers. Squeezing the main vine tips off when they’re two feet long will encourage branching.

A pumpkin can be harvested when you knock on it and the gourd sounds hollow. Carefully cut the pumpkin away from the vine. If you want to store the fruit long-term, leave a long stem and set the pumpkin in a sunny area for 10 days to cure the skin.