Pumpkins are technically a fruit in botanical terms. Botanically a fruit is the mature ovary of a flowering plant which is formed from the fertilized ovaries of flowers and serves as a means for plants to protect and disperse their seeds.
Vegetables refer to various edible parts of plants, typically those that are delicious in flavor and used in cooking. They can be roots (e.g., carrots, potatoes), stems (e.g., celery, asparagus), leaves (e.g., lettuce, spinach), flowers (e.g., broccoli, cauliflower), etc.
Therefore, botanically pumpkins are fruits but culinary oculturally, pumpkins are referred to as vegetables because they are used in cooking. To enjoy this delicious & nutritious vegetable according to culinary uses or a fruit botanically you can grow them in your garden of farm from seeds.
They can be grown in USDA zones 3, 4, 5, 6, 7, 8, and 9. To grow pumpkins, start sowing seeds in spring and late summer season.