How to Collect and Save Green Bean Seeds

Green beans (Phaseolus vulgaris), sometimes known as pole beans, bush beans or snap beans, are typically enjoyed for their crisp, tender green pods. With the right treatment and care, however, these pods mature and dry out and can be stored and eaten later, or used as bean seeds and replanted next year.

Immature beans that haven't fully dried out may become moldy in storage. In contrast, if you wait too long, the bean pods will burst open and the seeds inside will get scattered and dirty. Use the calendar to alert you to when it's necessary to monitor bean pods daily for harvesting. Pay attention to these three dates:

The day the bean plants germinate.

The day the first bean pods grow.

The six-week mark after the pods appear.

After planting, green beans generally germinate within two weeks. It takes another 45 to 60 days for most green bean plants to produce their first pods. After the pod appears, it takes about six weeks for the pod to mature, ripen and fully dry out. This six-week mark is crucial and is when you should begin checking individual pods to see if they're ready for collection.

Leave the green bean pods on the plant until the pods are completely dry. Harvest-ready, dried bean pods have several key characteristics:

Review the pod's appearance. It should have an even, brown color.

Shake the individual pod. You should be able to hear the seeds rattling inside.

Break open a pod, take out a seed and bite it to test for maturity. The seed should barely get scratched or dented if you bite it.

Dry weather is crucial for dry bean pods. If the weather turns rainy, cut the bean plants off at their base, bring them indoors, tie them together in a bunch and hang them upside down in a warm, dry location until the pods exhibit the three key characteristics that indicate they're ready for seed collection.

Plucking a dried pod off the plant and cracking it open manually is one way to collect green bean seeds, but this chore can become tiresome if you need to repeat it for multiple plants. Instead, try the faster pillowcase method:

Old pillowcase

Two large bowls

Room fan

Pluck the dry pods off the plant and place them into an old pillowcase.

Smash or beat the pillowcase against a hard surface, like the floor of a garage or the side of a kitchen counter. This breaks open the bean pods inside the pillowcase.

Empty the pillowcase's contents into a large bowl. The pods will all be shattered, with bean seeds mixed in with the chaff and pod debris.

Pour the bowl's contents into a second bowl while standing in front of a room fan. As you pour, the circulating air from the fan will blow away the chaff while the heavier bean seeds fall into the bowl.

Repeat the process several times, pouring the beans from one bowl into the other bowl until all the bits of bean pod debris have been separated and only beans remain in the bowl.

Place the green bean seeds into a sealable, airtight container, such as a glass Mason jar. Although some people store seeds in paper sacks or plastic bags, these fail to adequately lock out moisture. Excessive moisture content will decrease the longevity of bean seeds.

Label the container with the type of seed and the date you put the seeds into storage.

Pour a couple tablespoons of dry milk powder onto a piece of tissue paper or cheesecloth. Fold the tissue paper or cloth and place it in the jar. The milk powder will suck any moisture out of the air and help keep the bean seeds dry.

Place the seeds in a dark, cool place, such as a refrigerator. The ideal temperature range to store seeds is 32 degrees to 41 degrees Fahrenheit.

For the best germination results, plant any green bean seeds you collect within a year.