English cucumbers contain no viable seeds. Photo: producegeek.com
Question: Do store-bought (English) cucumbers produce seeds that are viable for planting? Can I harvest them, clean them, dry them, then sow them? I tried and they were very hard to extract; plus the seeds appear to be about the size of an atom. How do you handle them? Last but not least, will they grow and will they produce cucumbers? If all are female, how do they pollinate?
Answer: The fast and easy answer to all of your questions but the last one is simply “no.”
The seeds are not viable, so you can’t sow them. In fact, the seeds of store-bought cucumbers of any kind, even the stockier, shorter regular cucumbers (slicing cucumbers), with larger, more readily extractable seeds, will never be viable, because we eat cucumbers when they’re immature and supermarkets and stores only sell ones that are in an edible state.
Cucumbers turn big, yellow, brown or orange and insanely bitter at maturity and are generally considered no long edible at that point. If you grow regular cucumbers in your garden, you could easily allow a cucumber or two to mature on the vine if you want to produce your own cucumber seeds, harvesting them and drying them at the end of the season. But store-bought cucumbers will always be green and immature at purchase, because they’re sold when they’re ready to eat… and they’re ready to eat when they’re immature.
Secondly, English cucumbers (also called Dutch, hothouse or greenhouse cucumbers), those long, narrow cucumbers you see wrapped in plastic in supermarkets, the ones with thin skins you don’t have to peel, are considered seedless. There is simply no seed to harvest! The tiny little dots in the center of the fruit you noted are not seeds, but simply embryos that were never pollinated. They can’t sprout even if you did let the fruit grow to maturity or even beyond.
This kind of cucumber is parthenocarpic, that is to say it produces fruit without having been fecundated (that’s why its seeds never fully develop). Moreover, it produces only female flowers, eliminating the risk of accidental self-pollination. As a result, English cucumbers are almost always grown commercially inside a greenhouse. This prevents any insects from fecundating them using pollen from male flowers from a regular cucumber nearby, as that would result in misshapen, seedy fruit.
You can’t produce English cucumber seeds at home. They’re raised under glass by carefully crossing inbred lines. (Growers can chemically fiddle with even parthenocarpic plants to force them to produce male flowers with viable pollen, allowing such crosses to be made). The extra manipulation means English cucumber seeds are considerably more expensive than standard cucumber seeds … either that, or there will be fewer seeds in the packet you buy.
Cucumbers aren’t the only parthenocarpic plants that produce fruit. Bananas have been doing so for thousands of years. Those minuscule black dots inside the banana are just tiny unpollinated embryos. If ever a banana were pollinated (unlikely for genetic reasons), the giant, hard seeds that form would take up so much space there would be little flesh in the fruit to eat.
Bananas make life simpler for growers than cucumbers, though. They’re perennials and reproduce through offsets (pups); there is no need to restart them annually from seed.