If you are growing only one variety of a plant species or you give a lot of space between varieties, you don’t have to worry about preventing cross pollination.
If you want to save open pollinated seeds and make sure they don’t cross pollinate, you should consider using a cross pollination barrier bag and understand how the plant creates its produce by self pollination or not and how the plant creates its seeds and when.
Self Pollinating –Â If you are saving seeds from self pollinating plants like beans and peppers, you can attach the cross pollination barrier bag on the stem so the bag covers the flower before it opens and keep it on at least until the veggie starts to form.
Not Self Pollinating – Since plants in the cucurbit family have separate male and female flowers and pollinators like to fly to both flowers, you should put the cross pollination barrier bags on both flowers before they open, remove the bags long enough to hand pollinate from the male flower to the female flower and keep the bag on at least until the veggie or fruit starts to form.
No Pollination Required for Produce – While no pollination is required to produce flowers and edible parts of plants like lettuce, carrots and herbs, these plants can cross pollinate once the plant blooms. For instance when lettuce and carrots start to bolt, they will produce flowers that can be cross pollinated by those little pollinators like bees before the seeds are set. You should put the cross pollination barrier bags on the blooms before they open and keep it on.
Also, the seeds that you purchase typically last about 3 years if kept in a cool spot. If you are new to seed saving or don’t have a lot of spare time, you don’t have to save each variety in the same year. For a small garden you may only need to protect a few flowers for each variety to get enough seeds.
