If you live in a drier, more arid area, seed can be planted up to 1.75 inches deep to keep them in a moisture zone. Normally, shallow cultivation just enough to control weeds is sufficient for this crop. Rows should be about 4 feet apart, with hills containing two or three seeds. Each hill should be about 3 feet apart. Although pumpkin plants produce a profusion of flowers throughout the life of the plant, however, as a rule of thumb, about 2 pumpkins per vine can be expected.
All pumpkins produce separate male and female flowers on the same plant for natural pollination.
While pumpkin size is generally controlled by genetics, any factor that limits plant growth will adversely affect it's size. This includes water, temperature, insects , diseases, pollination, fertility, soil type, plant population, weeds, etc. It is not uncommon for some pumpkins to wither or rot and die soon after flowering. This condition may be due to either to poor pollination or the natural tendency for a plant to let some pumpkins die so that the good ones will live, natural selection. Other factors that can contribute to the dying off of some pumpkins include overcrowding of plants, prolonged periods of cool and cloudy or rainy weather or drought.