Brandywine tomatoes and Moon and Stars watermelons are showy heirlooms that grab headlines, but the humble potato has taught us all a lesson or two about the need for preserving and planting genetic variety. Potatoes (Solanum tuberosum) as a group are one of the most diverse vegetables. They originated in the high elevations of the Andes mountains in Peru, Columbia and Bolivia and were probably domesticated over 10,000 years ago. Since then, they have become one of the most important food sources throughout the world. Potatoes are especially popular in high altitude areas where many grains will not grow. They found their way to North America via Irish settlers.
Most people never notice the seed pods that form on potato plants. Not all plants set seed, but be on the lookout for round green pods about the size of a dime. Supposedly this is how Luther Burbank got his start in plant breeding. He stumbled on some potato seed pods and replanted them, looking for an improvement over the parent potato. The rest is culinary history.
If you should find some seed pods on your plants and want to do some experimenting on your own, the pods should be picked when they have had about two months to fully mature. They will still be a bit soft at this point, but they will easily pull from the plant and may even begin dropping on their own. Squeeze the seeds out of the pods and cover with water. The good seeds should sink to the bottom. Dry and save those seeds. Potato seeds prefer a warm (60 degrees F) soil to germinate.
However, while potatoes do set seed, they only grow true to type when reproduced vegetatively – by replanting the actual tubers or potions thereof or by taking cuttings. Replanting the tubers is good and bad. It’s great for seed savers. You don’t have to worry about cross pollinating, because you are not interested in seed. But it is also a great way to transmit disease. The Irish Potato Famine was due in part to the carryover of disease from one year’s crop to the next year’s seed potatoes.
The Irish had been planting potatoes for over 200 years before the famine started in 1845. Potatoes ease of planting and storage, high nutrition, and calories per acre planted made them favorites of poor farmers. They also constituted the bulk of their diet.