a pile of pumpkins
Updated: September 14, 2023

Planting pumpkin facts

  • Hardiness: Very tender warm-season annual. Frost will injure top growth; needs warm weather to grow.
  • Planting: Mix compost into the soil before planting and plant on a level part of your garden. For transplants, sow seed indoors in 3-inch diameter containers 3 weeks before planting time (about mid-May). Seed or transplants can be planted through black plastic or landscape fabric to hasten maturity. After seedlings emerge, pinch out all but the strongest seedling. Handle transplants gently and disturb the root system as little as possible. A second crop can be planted between June 15 and July 1. This crop will be harvested around the time of the first frost. Full sun requires direct light at least 6 hours/day; prefers 8 - 10 hours/day.
  • Days to maturity: Most pumpkins require more than 100 days to ripen.
  • Spacing: Plant 2 to 3 seeds every 3 ft. to 4 ft. apart in rows that are about 8 to 12 feet apart after all danger of frost has passed and the soil has warmed. Plant the seeds about ½” deep in the soil. Expect germination in 7 to 10 days. Thin seedlings to a single plant.
  • Fertilizer needs: High requirement for nutrients, either from soil organic matter or fertilizers. Fertilize prior to planting; side-dress when fruits first develop. Refer to Fertilizing Vegetables for details.
  • Approximate yield: 10 to 20 pounds per 10-foot row.

Pumpkin problems

Cucumber beetles
Downy mildew
Vegetables not true to type
Powdery mildew
Pollination problems
Squash beetle
Squash bug
Squash vine borer

Growing and care of pumpkins

  • Pumpkin is a member of the genus Cucurbita and the family Curcurbitaceae. Fruits grow on long vines and comes in many varieties and colors, but are mostly orange when ripe.
  • It is harvested and eaten in the mature fruit stage, when its color has changed from green, usually well into the fall.
  • Like other winter squash, it can be stored intact for carving and eating later in the season. Some varieties are preferable for carving, some for making pies.
  • Pumpkin seeds can also be cleaned, dried, and salted for eating.
  • Similar to other members of the squash family, pumpkins produce male flowers for 1 to 2 weeks before female flowers appear. This is a normal growth habit and varies with cultivars. For a flower to develop into a fruit, pollen must be carried by bees from male flowers, on the same plant or on different plants, to the female flower (the one with the tiny fruit below the flower). Poor fruit-set is common during rainy weather when bees are inactive. Avoid using any pesticides during the bloom period to prevent poisoning pollinators.
  • Watering – Water deeply and regularly at the base of each plant, especially during hot, dry weather and once fruits start to form.
  • Weeding –Remove all young weed seedlings by hand or with a hoe and use a mulch around plants to keep weed seeds from germinating.

Tips on growing giant pumpkins

  • Check seed catalogs and garden centers for cultivars known to produce large fruit- such as ‘Atlantic Giant’, ‘Big Max’, or ‘Big Moon’. It will take 4 months to get these pumpkin varieties to produce pumpkins in the 100+ pound range.
  • Mound up the soil in the middle of the planting area and plant 3-5 pumpkin seeds about ½ in. deep. When the plants have their second set of leaves keep the strongest plant and cut the others at ground level, rather than pulling, to prevent injury to the roots of the remaining plant.
  • Select one fruit: monitor the growth of the baby pumpkin fruits on your plant. When they are 6-8 inches in diameter you should keep the largest and fastest-growing fruit and remove the others. Remove all new blossoms that appear. Place a piece of cardboard under your giant pumpkin to prevent soil rots. You may want to try rolling the pumpkin very gently into a new position each week to keep it from becoming lopsided.
    • Prune vines – After selecting your one fruit, pinch back the ends of your vines to direct the plant’s energy into the fruit. Some gardeners gently lift and move the vines to run in one direction to make access easier. Trim main vines and lateral vines as needed again later in the season.
     Fertilizing – Fertilize plants with a water-soluble fertilizer every week according to label directions. Apply the liquid fertilizer to the soil around the base of the plant. The fertilizer should supply nitrogen, phosphorous, and potassium. Alternatively, you can sprinkle a dry fertilizer around the base of your plant every 2 weeks. Over-fertilization can cause excessive vine growth and split your pumpkins.

Harvesting pumpkins

  • Generally, pumpkins are harvested in late September or October before heavy frosts hit the planting area.
  • Use a sharp knife or pruning shears to cut them from the vines, leaving 3 to 4 inches of stem attached to each fruit. 
  • Try to avoid cutting or bruising the fruit.
  • The rinds need to be hard and firm for pumpkins to store well.
  • Light frost will not damage the pumpkin skin or flesh but will kill the vines. Temperatures under 28 degrees F. could injure fruit.  

Storage and preservation

  • Store pumpkins in a dry area that stays between 50 and 55 degrees F. 
  • For pumpkins that ripen before Halloween, wash them with a weak bleach solution (1 TBS. of bleach mixed in 16 oz. of water), rinse with water, wipe them dry, and store in your basement on a pallet or platform that allows air to circulate around the fruit.

Still have a question? Contact us at Ask Extension.