Pumpkins (Cucurbita) and Gourds (Cucurbitaceae)
Other vegetables in the same family include watermelons, squash, cucumbers, and cantaloupes. The cultivation of these plants predates colonial America. In fact, gourds were likely among the first plants domesticated by humans and were used as utensils as early as 2400 B.C. While pumpkins and gourds belong to the same family, the cultivated species of both vary widely, although there is some overlap.
Temperature
Transplanting: Germinate at 75-95°F
Direct Seeding: Sow pumpkins in late spring when the soil temperature is at least 70°F. Pumpkins are highly sensitive to cold temperatures (below 50°F), and both the plants and fruit can be damaged by even a light frost. The ideal temperature range for pumpkin production during the growing season is between 65–95°F. Temperatures above 95°F or below 50°F can slow the growth and maturity of the crop.
Soil
Pumpkins grow best in fertile, well-drained soil with a pH of 5.8–6.8 and minimal compaction. The soil should have good water infiltration and retention. If planting on sandy soils, irrigation is essential for optimal plant growth, consistent fruit set, and development. Wait until the soil temperature reaches 60°F at 3-inch depth before planting. Seeding in cooler soils can lead to injury from seed corn maggots.
Planting
Transplanting: Sow 2-3 seeds per 2" container or plug flat about 3 weeks before transplanting. Thin to 1 plant per cell. Harden plants 4–7 days before transplanting. Transplant after danger of frost has passed.
Direct Seeding: Sow 2 seeds at the recommended interval for the vine type, ½–1 inch deep. Thin to 1 seedling per spacing after establishment.
Spacing
- Bush types: 4–5' between rows
- Short-vine types: 6' between rows
- Long-vine types: 12' between rows
Pumpkin - Large: 48–72" in-row, 72–96" between rows
Pumpkin - Small: 24–60" in-row, 60–80" between rows
Harvest
Pumpkins: Tolerate 1–2 light frosts, but below 28°F damages fruit. Clip handles when color is full. Avoid lifting by handles. Cure 5–7 days in field or at 80–85°F indoors. White types should be removed from sunlight when foliage dies back. Store at 50–55°F, 50–70% RH for 2–3 months.
Gourds: For C. pepo, harvest when color is developed and stems are dry, before hard frost. Cure 5–7 days indoors, wash, dry, and seal with polish. For L. siceraria, harvest when color fades and stems dry. Leave on vine as long as possible. Store 3–6 months to fully dry.
For more information, please see links below:
- New Mexico State - Pumpkin/Gourd Guide
- Penn State - Pumpkin Production
- University of Kentucky - Pumpkins
Note: This information is summarized. Additional details and expanded guidelines can be found in our production sheets available in the Holmes Seed Grower's Guidebook.
Downloadable Copy: