Seed saving is easy but there is more to it than harvesting the seeds. It starts with planting. Different plants are pollinated in different ways. Some plants are more likely to cross pollinate. Cross pollination means the seeds are now hybrids with unknown outcomes. The plants from these seeds will not produce fruit that is the same as their parent plants. This is where things can start to get a little tricky. This is not what we want to happen when we are saving seeds. Don't worry, it's not too tricky if you are aware of which plants can cross pollinate and how to work around this.
Understanding How Pollination Works
To understand how pollination works we need to understand the anatomy of a flower. All flowers have sex organs. Perfect flowers have both male and female sex organs in the same flower such as in a tomato plant. Other plants like squash have male flowers and separate female flowers. The males sex organ of a flower is called a stamen consisting of the anther and filament. The anther contains a pollen producing sac that splits open as it ripens. The female sex organ of the flower is called a pistil which consists of the ovary, style, and stigma. Once a fertile pollen grain comes into contact with the stigma, by wind, insects, or the maturing of the flower, a pollen tube is formed traveling down the style and to the ovary where it fertilizes the ovules within the ovary. At this point the ovary develops into either a seed's pod or fruit and the now fertilized ovules become the seed which we save for next season's planting.
3 Types of Pollination
Let's take closer look at the three way plants are pollinated.
Self pollinating plants have both male and female sex organs in each flower. In some self pollinating plants fertilization occurs before the flower even opens. Other self pollinating plants can also be pollinated by insects. Fruit set is increased by the addition of insect pollination.
While insects can pollinate self pollinating plants, they are absolutely imperative for plants with separate male and female flowers. Cucurbits, for example, like squash and cucumbers, have separate male and female flowers. Female flowers have an enlarged ovary below the flower. These look like mini fruits. Male flowers do not have this. The pollen from the male flowers has to be carried by insects to the stigma of the female flowers in order for pollination to occur. There are a few perfect flowers that although they have both male and female sex organs, the pollen from one flower can not grow in the style of the same plant. It needs a different plant. Furthermore, some flowers shed pollen before stigma is ready to except it. So even though it has both male and female parts in each flower, the pollen from one flower actually pollinates the stigma of another flower through insect pollination and wind.
Many grasses and trees are pollinated by the wind. The most common garden plants that are wind pollinated are corn and spinach. The pollen from both can be carried for miles before coming to a resting place. Corn pollen is produced in the tassel. When the stalks are shaken by the wind pollen falls from the tassels, which contain the male flowers, and lands on the silks which extend from the ears, the plant's female flowers. Corn pollen can travel for miles and miles.
In order to collect pure seed for seed saving we need to be sure that our plants are not getting cross pollinated with other varieties. We can do this by isolating different varieties by various isolation distances, time isolation, caging, bagging, and hand pollination. Just to let you know, so you don't get overwhelmed here, I only use distance isolation. None of these methods are hard. Some just require a little more attention and/ or supplies.
In the printable Seed Saving Planting Guide I created a list of all the different distances required for each of the most common garden plants. Some plants such as squash, however, require too much distance (1/2 mile) to reasonable be able to grow two different varieties and save seed. But different species will not cross pollinate although they are in the same genus.
There are four main species of squash; maxima, mixta, moschata, and pepo. As long as you only grow one variety per species you will not have a risk of cross pollinating. That is exactly what I do! So, for example, this year I am growing zucchini a pepo species, Tennessee Sweet Potato a mixta species, Tromboncino a moschata species, and Candy Roaster a maxima species.
Other plants like eggplants are self pollinating but some can still be pollinated by insects so it is best to keep different varieties separated by 50'. This is a lot easier for a home gardener to accomplish. It may be as simple as planting one variety in the front of the house and one variety in the back of your house.
This gives you the distance required as well as an obstacle. Walls, buildings, and other tall barriers reduce the risk of cross pollination.
Are you ready? Download your free Seed Saving Planting Guide below!
Printable Seed Saving Guide
I hope that you have found this helpful. If you have any questions then let me know in the comments or send me an email. You know I am always here to help you!
P.S. I had so much fun creating this Seed Saving Planting guide that I made matching stationary! It has 5 unique design that you can print over and over again and send to all the special people in your life. Handwritten letters may not be as common anymore but that makes them all the more special to receive! Grab this instant download and send the special ones in your life a little smile.
Hello, I'm Jaci. I look forward to sharing my gardening and homestead adventures to help you reach your gardening goals! If you have any questions then don't be shy, I'd love to hear from you. Send me a message and I will be glad to help!