Select large, healthy pumpkins from healthy plants. Remember, large begets large, and round begets round.
If one plant appears more disease resistant than others, use a pumpkin from this vine.
Select two or three (or more) pumpkins, if possible. Using several fruit increases the likelihood of good germination.
Extract the seed from the pumpkins.
Wash and rinse seeds thoroughly, using soapy, lukewarm water. Do not use hot water, and do not soak them in water.
Drain seeds in a strainer.
Spread seed out on a screen.
Stir the them often the first two days. Turn them over as you stir.
Allow the seeds to air dry in a cool, dry area for three weeks. Longer is recommended. Do not cut the time short, even if the seeds appear “dry”.
Store them in a bag, envelope or jar in a cool dry place. Use of an air tight jar is not recommended, because if the seeds have not thoroughly dried, they will mold and rot.
Mark the them with date and type of pumpkin.
Some people place the seed in a freezer for a couple of weeks before sowing them, to replicate nature’s winter cycle. This is optional and I have seen no difference.