2 important reasons why pumpkin crops can be threatened

Planting and growing your own pumpkins on your own is a lot of fun! However, there are many difficult tasks to be solved on this path. If your pumpkin plants have grown to an enormous size but are still not fruitful, there are probably problems that prevent them from fully bearing fruit.

Lack of pollinators

Pumpkins depend on bees and pollination. Therefore, if there are not enough bees visiting your garden, this can become the number one problem. You can attract them to your site by growing these plants and providing valuable food for these delightful gardeners. In addition, you can create a home for bees yourself, making them regular guests who will responsibly pollinate various plants during the summer.
Pollination occurs when a bee visits a male flower before visiting a female flower and transferring pollen on its paws and fur. In pumpkins, male flowers are often the first to appear. The female flowers will begin to bloom in a few weeks. They can be identified by the small fruit bud under the flower, while the male flower grows directly from the pumpkin vine.
If you are still unsure if laborers are visiting your garden, you can manually pollinate the flowers. This can be done with a thin brush or cotton swab. Follow the development of the female flowers. On the very first day when they open, you need to extract some pollen with a brush or cotton swab from the stamen of male flowers and transfer it to the pistils of a female flower.
You can do without a brush. To do this, you should carefully pick the male flower, remove all the petals, leaving only the anthers, and gently touch them to the pistils of one or two female flowers. Hand pollination is best done around 10 am. Since the dew has already dried up, the heat has not yet come, and the flowers, which opened at dawn, are ready for pollination.

Bad conditions         

If you are trying to grow pumpkin during a hot season, the unfavorable heat conditions can slow down the vegetables' performance. Hot and humid weather can retard the development of female flowers, and if the soil becomes dry, any existing fruit may stall to conserve the plant's resources.
Pumpkins need plenty of water to stay healthy.
This makes it difficult to grow them in containers that can only contain a limited amount of liquid. After rain or watering, mulch the soil around the base of the plant using well-rotted compost or manure. This will help keep the roots cool and moist.
Too much nitrogen in the soil can also inhibit the reproduction of female flowers, which means that you are left with only male flowers that cannot pollinate each other. Signs of nitrogen toxicity in pumpkin plants include yellowing of the leaves and “burnt” edges, making them brittle and brown in color. Avoid feeding plants with plant foods that are high in nitrogen and feed them with tomato fertilizer instead.