Pumpkin (Cucurbita pepo; C. maxima; C. moschata; C. mixta)-Hort Answers - University of Illinois Extension
University of Illinois Extension

University of Illinois Extension

Hort Answers


Cucurbita pepo; C. maxima; C. moschata; C. mixta

Select a site with well-drained, fertile soil. Control perennial weeds. Test the soil and apply recommended amounts of nutrients. Apply recommended amounts of phosphorus and potassium fertilizers before planting. Apply 60-100 pounds of nitrogen per acre. Apply about 70% of the recommended amounts of nitrogen pre-plant and the rest as sidedressing or through drip irrigation when plants start to vine. Pumpkin can be grown on bare ground or in plasticulture system. Plant treated seeds when soil temperature is 58 to 60 degrees Farenheit. Move bee-hives to patch when flowers start to appear. Irrigate when needed. Control the weeds by putting straw mulches around the plants or using plastic mulch, and by cultivation.  

Pumpkins and squash belong to the Cucurbitaceae family. Generally pumpkins belong to the Cucurbita pepo, C. maxima, and C. moschata species. The C. pepo species are usually recognized as the true pumpkin. Pumpkin varieties within this group have orange-yellow flowers, and fruits with bright orange skin and hard, woody, distinctly furrowed stems. This group also includes gourds, vegetable marrow, Pattypan summer squash, scallop summer squash, gray and black zucchini and summer crookneck squash.

The maxima species also contains varieties that produce pumpkin-like fruit but the skin is usually more yellow than orange and the stems are soft and spongy or corky, without ridges and without an enlargement next to the fruit. They don't really make good handles for jack-o'-lanterns. Varieties such as Atlantic Giant, Big Max and Show King are often listed as pumpkins but are more properly called pumpkin-squash or squash- type pumpkins. Other members of the maxima group are Hubbard squashes, banana squashes, buttercup squashes and turban squashes - in short, most autumn and winter squash.

The moschata species containvarietiesthat producelong and oblong fruits . Mature fruits havetan rather than orange skin. The stems are deeply ridged and enlarged next to the fruit. Members of this group are used for canned pumpkin pie production. The other non-pumpkin members include the squash-like cushaw, winter crookneck squash and butternut squash.

The mixta species contain varieties that have yellow to green or orange flowers, and produce cylindrical, curved fruits that are bulbous at the apex. The rinds are hard to soft , and they have hard, five angled, large fruit stem. Some of the white pumpkins, blue or blue-green pumpkinsbelong to this group. The other members of this group include Cushaw squash.

When growing pumpkins, select varieties that perform well in your area.

Planting Time
Pumpkin is a warm season vegetable that is planted after the danger of frost is gone, and the soil is warm enough for the seed to germinate. This depends on the frost-free date in your location.


Harvest Time
Pumpkins mature at different times. Pumpkin for Halloween are planted so that they mature as close as possible to the Halloween time. Pumpkins for making pie can mature early or late depending on the variety. Harvest pumpkin fruits when the rind is hard and cannot be poked by finger-nail, and the fruit is orange in color. Avoid cuts and bruises when harvesting fruits.


Pumpkins are spaced according to growth habit (vining or bushy). Plant pumpkin seeds one inch deep when the soil is warm. The vining types require more space than the bushy types. The vining types require a minimum of 50 to 100 square feet per hill. Plant seeds one inch deep (four or five seeds per hill). Allow 5 to 6 feet between hills, spaced in rows 10 to 15 feet apart. When the young plants are well-established, thin each hill to the best two or three plants.

Plant semi-bush varieties one inch deep (four or five seeds per hill) and thin to the best two plants per hill. Allow 4 feet between hills and 8 feet between rows.

Plant miniature varieties one inch deep, with two or three seeds every 2 feet in the row. Rows should be 6 to 8 feet apart, with seedlings thinned to the best plant every 2 feet when they have their first true leaves.

Plant bush varieties one inch deep (1 or 2 seeds per foot of row) and thin to a single plant every 3 feet. Allow 4 to 6 feet between rows.


Soil Conditions
Moist, Well-Drained
Exposure/Light Requirements
Full Sun
Pests and Problems
Additional Notes


Related Resources
Home, Yard & Garden Pest Guide
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic