Gardeners wishing to warm the soil early and prevent weed growth around their pumpkin patch often lay down black plastic mulch before they plant their pumpkin seeds. Plastic mulch also keeps the soil more evenly moist, which helps you grow larger pumpkins. Prepare the soil first by enriching it, because pumpkins require a rich soil full of organic material. This preparatory work will enable you to reap a healthy pumpkin harvest in the autumn.
Prepare the planting area in the early spring when the soil dries enough to be workable. Cultivate the soil to a depth of 6 to 8 inches with the garden spade. Add 4 inches of compost to the top of the soil, and work the compost in thoroughly with the garden spade to incorporate it fully. Level the soil surface using the rake.
Spread the black plastic sheeting over the planting area. Secure the edges of the sheeting with bricks or rocks.
Cut holes in the black plastic for the pumpkin mounds. Set the holes so that they are approximately 3 feet apart on all sides, and make the holes approximately 4 inches in diameter.
Dig a shallow hole in the center of each plastic sheeting hole using a trowel. Make the holes 2 inches deep. Plant two pumpkin seeds in each plastic sheeting hole. Cover the seeds with 2 inches of soil.
Water the newly planted pumpkin seeds thoroughly to saturate the soil. Allow the soil to dry between waterings, and then water to moisten the soil again. Do not allow the soil to stay dry between waterings.
Harvest pumpkins when the vines are withering and dry. Slice the pumpkins from the vine (leaving 1 to 2 inches of stem attached to the pumpkins) before the first frost. Cure the pumpkins at temperatures between 75 and 85 F for two weeks immediately after harvesting. After curing the pumpkins, store them at temperatures between 50 and 70 F.