Green nasturtium seeds are the developing, round pods that remain on the plant after the flower has faded. The plant produces these pods throughout the growing season, offering a continuous harvest opportunity. Nasturtium seeds serve a dual purpose, being sought after for their peppery flavor in the kitchen and for future planting.
Harvesting Green Seeds for Culinary Use
Harvesting the seeds while they are still green is done to create a pickled condiment often referred to as “poor man’s capers.” The optimal time for harvesting is when the seed pods are plump, firm, and a vibrant green color. They should feel solid to the touch, indicating they are fully formed but not yet beginning the natural drying process. Avoid any pods that show signs of wrinkling or have started to turn yellow or brown, as these are past their prime for pickling. Harvesting involves gently pulling or snipping the pods from the stem. Harvest the pods only when they detach easily from the plant, ensuring they are at the correct stage of immaturity.
Proper Preparation of Green Nasturtium Seeds
The raw, green seeds contain isothiocyanates, potent mustard oils that give them an intensely strong, bitter flavor. Preparation is necessary to make them palatable.
Brining and Rinsing
The initial step involves washing the harvested pods to remove any debris. This is followed by a brining or soaking stage to mellow the flavor. To brine the seeds, submerge them in a solution of salt and water, typically for 24 to 48 hours. This process draws out bitter compounds and begins to condition the texture of the pods. After soaking, the seeds must be thoroughly rinsed to remove the excess salt before the final pickling process begins.
Pickling
The final step is to cover the pods with a hot pickling liquid, which usually consists of vinegar, water, sugar, and various spices. The heat from the liquid helps the pods absorb the pickling flavors and ensures a safe, preserved product. The seeds are then sealed in sterilized jars and allowed to mature for several weeks, completing the transformation into a pleasantly tangy and peppery caper substitute.
Harvesting Seeds for Propagation
Seeds intended for planting require full maturity, unlike those harvested for pickling. Green seeds are not viable for propagation because they lack the necessary internal development for successful germination. For planting, the seeds must be left on the plant until they are fully mature and dry. This stage is reached when the pods detach easily, turn a tan or light brown color, and become hard and shriveled. Mature seeds often drop naturally to the soil when fully ripe, but they can be collected directly from the plant if they brush off with minimal effort. After collection, the seeds must be spread out in a dry, warm location away from direct sunlight for a few weeks to ensure they are completely desiccated. Proper drying is necessary to prevent mold and establish the dormancy required for successful storage and later spring planting.