CULTURE:Fertile, well-drained soil with a pH of 5.8–6.8 is best.
TRANSPLANTING:Sow 2 seeds in 1½–2″ cell-type containers or pots. Thin to 1–2 plants/pot with scissors. Harden plants 4–7 days by reducing fertilizer, water, and temperature, and moving flats outside if there is no frost danger. Transplant out after danger of frost has passed; earlier only if plants are to be covered with floating row covers. Place about 18″ apart for bush and small-fruited varieties and 24–36″ for vining and large-fruited types. Take care not to disturb roots!
DIRECT SEEDING:Sow in late spring after frost danger when soil is warm — minimum 62°F (17°C) for treated seeds and 70°F (21°C) for untreated seeds — as seeds will rot in cool soil, especially cool, wet soil. Sow 2 seeds every 12″ (24–36″ for large-fruited varieties) ½–1″ deep. Thin to 1 plant per spot.
PLANT SPACING:Medium- and large-fruited pumpkin varieties need plenty of growing room for sufficient sunlight penetration for successful fruiting, and to grow to their fruit size potential. 6′ row spacing is recommended. See the comparison chart linked above for individual plant spacing per variety.
TIMING:Sow pumpkins to mature in September for the fall market. Too many days of sun on fruits in the field after maturity will bleach handles and sunscald the fruits.
FALL FROST:Frost kills leaves and can thus facilitate harvest; however, it can also damage fruits and cause spotting and poor storage. Mature fruits can usually tolerate 1 and sometimes 2 or 3 light frosts without substantial damage. Sprinkler irrigation wards off moderate frost damage to fruits.
DISEASES:Cucumber beetles can carry bacterial wilt and must be controlled. Gummy stem blight (black rot) causes black, sunken spots to appear on fruits in storage. Downy mildew may occur in damp weather, powdery mildew in cooler, dry periods and in late summer. Consult your local Extension agent for specific fungicide control. Choose well-drained soil to avoid phytopthora.
INSECT PESTS:Protect young plants with floating row covers. Cucumber beetles can carry bacterial wilt and must be controlled. In addition, squash bugs and vine borers can be a challenge. Pyrethrin offers some control. Squash bug eggs laid on the underside of leaves may be located and crushed. Keep borders well mowed. For vine borers, cut out of vines and hill soil over the wound. Clean up refuse in the fall, and spring-plow the ground to bury the pupae.
HARVEST:Before frost or after 1 or 2 light frosts. Clip stems close to the vine. Use care to avoid gouging or bruising. Avoid lifting fruits by handles. Store under cover with plenty of air. White pumpkins should be harvested once foliage starts to die back and placed under cover. Direct sunlight will cause white skin to turn yellow.
AVG. DIRECT SEEDING RATE:250 seeds/125′, 500 seeds/250′, 1,000 seeds/500′, 15M/acre @ 2 seeds/ft rows 6′ apart.