Saving Watermelon Seeds

Watermelons are cross-pollinators who need pollinators like bees and butterflies to spread their pollen in order to set fruit.  No pollinators- no watermelon.  Disaster!  
As cross-pollinators, its best to save seed from as many plants as possible to prevent inbreeding.  Keep that fact is in mind when you're picking the fruits for seed saving.
Watermelon seeds are easiest to harvest after a day or two of fermentation- here's the SUPER EASY step by step process of that:

1.  Let watermelon fully ripen on the vine before picking- the seeds need to come from fully ripened fruit.
2.  Dig seeds out of watermelon flesh and put in a bucket for fermentation.  You'll invariably get some watermelon flesh in there- don't worry, that helps the fermentation process.
3.  Eat and use the remaining flesh as desired.  We love to juice ours and freeze the juice.
4.  The bucket should be left at room temperature to help fermentation.  
5.  After 24-36 hours, fermentation will have allowed the heavy ripe seeds to sink to the bottom of the bucket, leaving the unripe fruit and flesh on the top.  You should be able to smell a little fermentation/alcohol type smell.  Fermenting longer than necessary will shorten the overall seed life, so we aim for 24 hours.  You can reach in (slimy!) and see if there are a lot of seeds that have sunk to the bottom to help you gauge the timing. 
6.  Pour the floating contents of the bucket off, adding water and utilizing several pours to get clean seeds at the bottom. 
7.  Strain and spread out seeds to dry in an airy place, or next to fans.  The quicker the drying, the longer the overall seed life.