Open-Pollinated, Self-Pollinated, Heirloom, Hybrid??
To understand these terms you need to go back to your high school biology class. Plants are all about making seeds. You could even say that their only goal in life is to reproduce. Sure those lovely flowers are nice to look at, but they are just traps for unsuspecting pollinators to spread pollen. Below is a picture of a flower.
Transfer of pollen from the stamen to the pistil leads to fertilization and the making of seeds inside an ovary. Pollen is transferred by wind, insects, birds, mammals and humans.
In people, children get genetics from mom and dad and have traits of each parent but will end up their own unique person. Seeds get genetics from their parent plants and will end up with a blend of inherited characteristics.
Some plants do things a little differently. Some plants keep all their male parts and female parts together in one flower. These plants are called bisexual or perfect. Some plants grow flowers that are all male or all female, and some plants grow both male and female flowers. If a flower is only functionally male or female it is called unisexual, imperfect or incomplete.
So now that your memory has been refreshed on basic plant biology, these terms will make more sense.
Open-Pollinated and Self-pollinated – Open-pollinated plants are pollinated by wind, insects, or gardeners to set fruit and make seeds. Self-pollinated plants do not need wind, insects or gardeners to pollinate their flowers as they have what is called ‘perfect’ flowers. ‘Perfect’ flowers contain both the stigma and pollen on the same flower and sometimes are pollinated just by the act of the flower opening. Frequently the term open-pollinated refers to both self and open pollinated plants.
Open-pollinated plants have stable genetics and come true from seed. This means that if you have a 'Big Orange’ squash plant, and you've ensured that there was no cross-pollination with other plants in your garden or pollen from your neighbor didn’t sneak in; the resulting seeds that you save from the crop you grow this year will produce 'Big Orange' squash plants, and not something else.
Cross-pollination can occur with both self and open pollinated plants, but only with plants in the same family. For example, if a bee visits a tomato plant flower then goes to a squash plant flower, you will not get ‘tomquash’ or a ‘squatom’ seeds from the fruit. But if your roaming bee visits a summer squash and then checks out an acorn squash those fruit may very well produce seeds that grow a strange fruit (which may or may not be edible) that you could call a ‘sumacorn’ or maybe a ‘acornmer’. Or perhaps those seeds will not set any fruit at all (sterile).
Self-pollinated plants are what we consider ‘easy’ to save seeds as the chance of cross-pollination is small. True open-pollinated plants are what we consider ‘medium’ or ‘difficult’ to save seeds because you need to make sure the plants are not cross-pollinated with other varieties.
Seed packets may say ‘open-pollinated’ or ‘OP’ or nothing at all on the seed packet. If nothing is specified, this is where you have to do a bit of sleuthing to find out whether a particular variety is open pollinated or hybrid. The internet is a wonderful resource for this.
Heirloom – are simply open-pollinated varieties that have been around for many years, usually at least 50 years or more. Think of them as the old standbys that usually produce consistent fruit every time you plant those seeds. Usually, seed packets will have the word ‘heirloom’ on the packet.
Hybrid – A hybrid plant is one that is bred from two different types of plants and is a result of a controlled breeding process. This is developed through a series of crosses where the parent plants impart the offspring with desirable traits. This process can be very involved and take many years. The result can be plants that have higher yields or are more resistant to disease. But the drawback to these plants from a seed saving perspective is that the genetics of hybrids is unstable and the seeds from these plants do not usually breed true.
We do have donated hybrid seeds in our seed library. They will grow great plants and produce, but please do not save the seeds from these plants. Seed packets may say ‘hybrid’ or ‘F1’ or not specify anything if they are hybrid seeds. Again, if nothing is specified, this is where you have to do a bit of sleuthing.
GMO – stands for Genetically Modified Organism. GMOs should not be confused with hybrid plants. GMOs have their genetic traits modified in a laboratory where specific genes are either added or deleted from a plant’s DNA. This is a very expensive process and at this time only commercial crops such as corn, soybeans, sugar beets and cotton are modified. At this time there are no GMO seeds available for gardeners. So though a seed company or a seed packet may say not GMO, right now it doesn’t really mean much as all packets of seeds available to us common folk are not GMOs.
So in summary, the Seed Library wants open-pollinated, heirloom or self-pollinated seeds that have not been cross-pollinated with another variety. Seeds from tomatoes, beans, peas, lettuce and native plants are what we call ‘easy’ to save seeds.
That being said, there are many types of vegetables and flowers that are open-pollinated, but are easy to be cross-pollinated. For example, all melons are in the Cucurbita family, so squash, pumpkins, melons, and zucchini will cross with each other. Isolate by 800 ft – ½ mile. Also, anything in the Brassica family – broccoli, Brussel sprouts, cabbages, cauliflower, kale, collards, and turnips all cross within each other and are insect pollinated. Separate by 800 ft – ½ mile. Corn is pollinated by wind and must be at least ½ mile away from any other corn. Onions are insect pollinated so separate by about a mile. Even some flowers will cross-pollinate with vegetables as carrots will cross-pollinated with Queen Ann’s lace flowers.
The Seed Library encourages you to only save seeds from non-hybrid tomatoes, beans, peas, lettuce and native plants as these seeds generally come true to seed. Advanced seed savers may want to try saving seed from the other types of plants using appropriate isolation distances or other methods to ensure no cross-pollination.
And, of course, you can purposely cross-pollinate varieties to come up with your own new plants!