Okra (Abelmoschus esculentus) is a warm-season vegetable that is grown primarily for its unripe seedpods. In certain parts of the world, okra is also grown for its ripe seeds, which can be pressed to produce a nutritious edible oil. Okra is highly susceptible to cross-pollination, so saving seed can be challenging.
Okra is a member of the Malvaceae family, which also includes roselle, hibiscus and cotton. These plants will not cross-pollinate with okra, so you can safely save okra seed even if you grow hibiscus flowers or live near a cotton field. Different varieties of okra do cross-pollinate, though, so you need to provide isolation if you want to maintain a stable okra cultivar.
Okra flowers are perfect and self-pollinating, which means that okra does not depend on insects or wind to move pollen from one flower to another. In other words, an okra flower can fertilize itself and form a pod without receiving pollen from a different flower. However, pollinating insects are still attracted to okra's large, conspicuous flowers, and they will move pollen from one variety to another if you do not stop them.
Isolation by Distance
The simplest way to prevent crossing between okra varieties is to grow only one variety in your garden. This is only feasible if you do not have any nearby neighbors growing other varieties of okra, because insects can carry okra pollen up to one mile. This range is probably excessive for home gardens, which attract fewer pollinators and include various barriers and alternate pollen sources. These factors tend to decrease isolation distances. If you are confident that you do not have any neighbors growing okra within about one-third of a mile, you can probably save seed without worrying about cross-pollination.
Isolating by Bagging
The term "bagging" refers to the process of placing some sort of barrier around a flower so it cannot be cross-pollinated. This technique allows you to save seed if you have neighbors growing okra or if you wish to maintain more than one cultivar. In the case of okra, tight-fitting cloth bags can be tied around the base of an unopened flower. Look for bulging flowers that will likely open the following morning. With the bag secured before the flower opens, insects never have a chance to bring unwanted pollen into the flower. Leave the bag in place until the day after the blossom opens to ensure that self-pollination is complete. Mark this blossom so you can recognize it later when the seed is ripe and ready for harvest.