Growing your own cucumbers can help you add a fresh taste to salads within minutes of the cucumber being picked. To make the most of your plant, you can save the seeds from your cucumber and store them for planting next year. To prepare cucumber seeds you'll want to plan for seed collection while there are still cucumbers on the vine and be prepared to wait until the time for harvesting the seeds is right.
Look over your cucumber plants and plan to leave one cucumber on each vine on up to six vines for seed collection. Allow the cucumbers to ripen past the eating stage for at least five weeks until they turn from deep green to golden in color.
Cut the cucumbers from the vine and bring the fruits inside. Cut open the cucumbers lengthwise, working with one cucumber at a time. Hold one cucumber half over a bowl and use a spoon to scrape down the length of the cucumber and scoop out the seeds and gelatinous material and let them fall into the bowl.
Collect from all of your cucumbers and pour the mixture of seeds and gel-like material into a jar. Leave the jar uncovered and set it in an undisturbed area at room temperature.
Stir the mixture daily for three to four days, as a fungus layer will form on the surface and the gel will dissolve. After four days, use a spoon to collect any floating pieces from the jar and discard. The good seeds will have sunk to the bottom.
Rinse the good seeds in a mesh strainer until they don't feel sticky. Spread out your rinsed seeds on a paper plate or coffee filter and set them in a warm, dry location to dry out completely for a week or two.
Store dried seeds in an envelope in a cool, dry location. Label the envelope as to the type of vegetable, common name variety, if known, and the date you collected the seeds.