Growing Pumpkins for Seed: Space, Timing and What to Do With the Harvest

Pumpkins are generous but greedy plants. They need space, sun and steady feeding, and in return they provide food for a whole season. The seeds inside are a bonus that many cooks treasure.

Choosing what to plant

Some pumpkin varieties are bred as hull-less or naked-seeded types, where the seeds have no thick white shell. These are often sold as oilseed or pepita pumpkins and produce green seeds that can be eaten straight from the pumpkin after drying. Ordinary carving or pie pumpkins also produce seeds, with a husk that is edible but chewier. Pick what suits your space, and check the days to maturity on the packet against the length of your growing season.

Planting and spacing

Sow seeds outdoors after the last frost, once the soil is warm, or start them in pots indoors three to four weeks earlier. Plant in mounds or hills enriched with compost, two to three seeds per spot, then thin to the strongest seedling. Vines can sprawl three metres or more, so give each plant generous room or train them up a sturdy trellis, supporting heavy fruit with slings of cloth. Water deeply at the base, avoiding wet leaves, which can encourage powdery mildew.

Feeding matters too. Pumpkins are heavy feeders, so mix plenty of well-rotted compost into each planting hill and give a balanced liquid feed once the vines begin to run. Mulch around the base with straw or leaves to keep the soil moist and to stop fruit from resting on bare, damp ground, which can cause rot. If you want one large fruit, you can remove some of the smaller ones after they set, though for seed production a few medium fruits work just as well.

Pollination basics

Pumpkins make separate male and female flowers. Female flowers have a tiny fruit behind the bloom. If few fruit are setting, bees may be scarce. You can hand-pollinate in the morning by touching a male flower's pollen to the centre of a female flower with a small brush. Remember that squash relatives cross easily, so seeds saved for planting may produce unexpected fruit.

Harvest and curing

Harvest when the rind is hard enough that a fingernail does not dent it, the colour is deep and the stem is dry and corky. Cut with a few centimetres of stem and cure the fruit in a warm, dry place for about ten days to help it keep longer. Handle gently and never carry by the stem.

Cleaning and roasting the seeds

Scoop out the seeds and rinse off the stringy pulp in a bowl of water. Dry them well on a towel. For roasting, toss with a little oil and salt and bake at a moderate temperature until golden, stirring often. Hull-less seeds only need a few minutes, so watch them closely. Keep any extra in a jar in a cool place and eat within a few weeks.

Use the flesh in soups, curries and baking, and compost the stems and scraps. Nothing from a pumpkin patch needs to go to waste.

This article is general information, not medical advice.