Saving your own seeds preserves the genetic material of your favorite plants for the next growing season. This process ensures you maintain a supply of varieties that perform well in your specific garden conditions. For spaghetti squash, the seed saving method requires careful attention at each stage to guarantee high germination rates and long-term viability. By following specific steps for selection, cleaning, and storage, you can successfully bank your squash seeds for future planting.
Selecting the Parent Squash
To ensure the seeds produce a plant identical to the one you harvested, you must begin with a squash from an open-pollinated variety, not a hybrid (F1) type. Hybrid squash seeds often produce unpredictable or low-quality fruit in the next generation, making them unsuitable for seed saving. The parent spaghetti squash should be fully mature, meaning it has developed a deep, uniform yellow color and a hard, woody rind.
The fruit should remain on the vine until the very end of the season, and ideally, be harvested with a few inches of stem attached to prevent rot during curing. Allowing the harvested squash to cure for at least one month in a cool, dry area further improves the maturity and vigor of the seeds inside. This curing period ensures the seeds have fully developed their protective coating and nutritional reserves.
Extracting and Cleaning the Seeds
Once the selected squash is ready, carefully slice it lengthwise and use a spoon to scrape out the stringy pulp and seeds from the central cavity. The seeds are encased in a gelatinous sac, or placental lining, that contains germination inhibitors which must be removed for long-term storage. To break down this coating, place the seeds and pulp mixture into a jar with water and allow it to ferment for two to four days.
During this time, the healthy, heavy seeds will sink to the bottom, while the pulp, non-viable seeds, and fermentation scum will float to the surface. After fermentation, pour off the floating debris and rinse the sunk seeds thoroughly under cool, running water. This rinsing step is important because any remaining sticky residue or organic matter can attract mold and bacteria, destroying the seeds during storage.
Essential Drying Techniques
After the seeds are cleaned, they must be completely dried before storage to prevent mold growth and maintain dormancy. Spread the seeds in a single layer on an absorbent, non-plastic surface, such as a ceramic plate, fine mesh screen, or paper towel. Avoid using plastic or metal surfaces, which can trap moisture and promote fungal development.
The drying process should occur in a cool, dark, and well-ventilated location, away from direct sunlight or heat that could damage the seed embryo. Depending on the ambient humidity, this air-drying phase can take anywhere from one to three weeks. A definitive test for dryness is the “snap test,” where a seed, when bent, should snap cleanly in half rather than bending or feeling pliable.
Preparing Seeds for Storage
When the seeds are dry and pass the snap test, they are ready for packaging to ensure longevity. The best approach is to place the seeds into a small paper envelope, which can absorb any trace moisture that remains. This envelope should then be sealed inside an airtight glass jar or tin to protect the seeds from fluctuating humidity and pests.
Clear labeling is required, noting the spaghetti squash variety and the date of harvest, as seed viability generally declines after three to six years. The ideal environment for long-term storage is a cool, dark place with a consistent temperature, such as a refrigerator kept between 35 and 40 degrees Fahrenheit. Maintaining a low, stable temperature and humidity helps keep the seeds dormant, preserving their ability to germinate when it is time to plant.