With a little basic understanding the mysteries of seed saving become clear. Home gardeners can save seeds on a small scale using common household equipment such as screens and fans. Read here to learn the fundamentals of seed saving in your home garden.
Open Pollinated (OP) vs Hybrid F1
When choosing plant varieties to save seeds from be sure they are open pollinated, not hybrid F1. Open pollinated means that the variety will produce true-to-type seeds using basic seed saving methods. Hybrid F1 varieties are the result of crossing two parent cultivars to produce a unique stable hybrid, or the F1 generation. Seed saved from hybrids will not produce true-to-type plants since the F2 generation will differentiate and show various genetic traits from the parent lines.
A popular example of a hybrid is Sungold cherry tomato. This is an incredibly delicious F1 hybrid. If you save seed from them and replant that seed you will not get Sungold again. Same with that great melon you got at the grocery store or even farmer's market. Chances are it was a hybrid and that the seeds you save from it will not bear true-to-type fruits.
Outbreeder vs Inbreeder
It is important to understand how the plant you save seed from is pollinated, as this will inform where and how many you need to plant.
Outbreeders need insect or wind to move pollen for pollination. Some outbreeders like corn or beets rely on the wind to blow their light pollen onto the reproductive parts dedicated to seed production of neighboring plants.
Other outbreeders, like cabbage or squash, need insects to move pollen from one plant to the other. Squash, melons and cucumbers, have two types of flowers on the same plants and insects must move pollen between the two flowers in order for seeds to set in the fruit's ovary.
Inbreeders can self pollinate with little or no external output besides a gentle agitation usually supplied by the breeze. Examples of inbreeders include tomatoes, lettuce, beans and peas. These have pollen bearing and seed bearing organs in the same flower, known as a perfect flower. The pollen will find its way to the seed ovules without insects. (Sometimes perfect flowers are outbreeders--We can save that discussion for a subsequent blog.)
Why is this important?
Outbreeders need a larger isolation distance between different varieties of the same species to keep seed true-to-type since insects can and will fly up to a mile or more. Inbreeders can be planted quite close together in a garden setting and will usually not cross pollinate between varieties of the same species.
For the beginning seed saver inbreeders are a great place to start!
This brings us to scientific names and why, as seed savers, it is important to pay attention to them. (This is also why we supply this info on our seed packets!) The first part of the name is the genus and the second is the species. The rule of thumb is that varieties with the same genus and species can cross pollinate. Plants of the same genus but different species will usually not cross. For example:
Cucurbita pepo ex. Dark Star Zucchini, Candystick Delicata
Cucurbita moschata ex. Waltham Butternut
Cucurbita maxima ex. Oregon Homestead Sweetmeat
These are three species of squash you can grow all at the same time and they won't cross pollinate (meaning pollen from one species landing on seed bearing parts of another and creating hybrid seed). However, if you were growing two varieties of Cucurbita pepo next to each other in the garden or even 20 ft apart they will likely cross since insects can fly large distances.
This is the suggested distance that varieties of the same genus and species should be planted apart in the garden to avoid accidental cross pollination. As a general rule inbreeders can be planted much closer together (5-30 ft) since insects do not generally manage to pollinate them while outbreeders need much more spacing (300 ft-2 miles).
These distances become very important if you are producing seed on scale commercially like we do with the intention of keeping varieties pure. However in the home garden there are hacks to help you and distances can be fudged a bit.