Because of the sprawling nature of pumpkin vines, some city gardeners feel they can't grow the seasonal plant. However, the small varieties of pumpkins grow well in large containers and are just as popular at Halloween as their bigger relatives.
Look in a gardening catalog or online for pumpkin seeds that produce small or miniature pumpkins. Purchase seeds for one or more varieties. Sugar Pie, Small Sugar and Jack Be Little are three proven varieties. These small pumpkins can grow in containers because the pumpkin vines are strong enough to support them. Larger varieties produce fruit that the vine cannot support and are unsuitable for containers.
Purchase or find a container for the pumpkin garden. A plastic kiddie pool is in inexpensive container that is easy to find, although any large, well-drained container will work. Prepare the kiddie pool for the garden by punching holes in the bottom of the pool for drainage.
Purchase or make a trellis or two. The trellis encourages the vines to grow up, instead of sprawling out across the ground.
Position the container in a sunny place in the yard.
Prepare the soil for the pumpkin container garden. Fill the container with potting soil or garden soil amended with compost. The compost gives the pumpkin plants an extra nutrient boost during the growing season.
Plant the pumpkin seeds 1 inch deep in mounds, three seeds per mound. The number of mounds depends on the size of the container; mounds should be positioned 4 feet apart, so you may have room for only one mound in a small container.
Place the trellis behind the container or in the case of a kiddie pool container, place it inside the pool and push it through the pool bottom. If the pool is large enough, add two or three trellises and tie strings between them to give the pumpkins another supportive place to grow.
Water and fertilize the pumpkin plants regularly. As the plants grow, train them on the trellis and strings. Keep the bed weed free by hand pulling any weeds as you see them.
Avoid using insecticides. Bees pollinate the flowers to produce the pumpkins. If you must spray, do it in the evening after the blossoms have closed for the day.
Harvest when the pumpkin rind is hard to the touch, and the color is a deep orange (in all but the white varieties). Cut the pumpkin from the vine using pruning shears, leaving a a 2-inch stem attached to the pumpkin.