Saving Bean and Pea Seeds
Bean and pea seeds are among the easiest to save for beginning seed savers. Both crops are primarily self-pollinating, meaning they rarely cross with other varieties growing nearby. This makes them ideal for gardeners who want to start producing their own seeds without worrying about complex isolation requirements.
This guide covers the practical steps for saving bean and pea seeds in Santa Cruz County. You will learn how to select plants for seed saving, when and how to harvest, and how to properly dry and store seeds for planting next year.
Saving your own seeds offers multiple benefits: you reduce costs, preserve varieties that perform well in your specific garden, and develop strains increasingly adapted to local conditions over time.
Why Beans and Peas Are Perfect for Seed Saving
Self-Pollination Advantage
Beans and peas have "perfect" flowers containing both male and female parts. Pollination typically occurs before flowers even open, so pollen transfers within the same flower rather than between plants. This self-pollination means a row of different bean varieties will generally produce seeds true to type without intentional isolation.
Cornell University Extension notes that beans have less than 1% outcrossing rate under normal conditions. Peas are similarly reliable, making both excellent choices for seed saving beginners.
Exceptions and Considerations
While crossing is rare, it can happen when bees force open flowers to access nectar. If you are growing runner beans (Phaseolus coccineus), crossing is more common since their flowers are designed to attract pollinators. For runner beans, maintain 1/4 mile separation between varieties or accept some crossing.
Fava beans have higher outcrossing rates than common beans because their larger flowers attract more bee attention. If growing multiple fava varieties for seed, separate by at least 50 feet or stagger plantings so flowering periods do not overlap.
Selecting Plants for Seed Saving
Good seed saving starts with selecting the right plants to save from.
Choose Your Best Plants
Mark your best-performing, healthiest plants early in the season, before you start harvesting for eating. Selection criteria to consider:
Health: Choose disease-free plants with vigorous growth. Do not save seeds from plants that showed disease symptoms, even if they recovered.
Productivity: Select plants that produce heavily. This trait passes to offspring.
Earliness or Lateness: If you want earlier harvests, save seeds from your earliest-bearing plants. The same principle applies to any trait you want to emphasize.
Trueness to Type: Make sure plants match variety descriptions. Off-type plants may be crosses from previous seasons or mislabeled seeds.
Population Size
To maintain genetic diversity and avoid inbreeding depression over time, save seeds from multiple plants rather than just one or two.
Minimum recommendation: Save seeds from at least 6 to 10 plants Better: 20 to 30 plants if space allows
For home gardeners saving seeds casually, even saving from just a few plants works fine for several generations. But if you plan to maintain a variety long-term, larger populations preserve genetic health.
When to Harvest Seeds
The key to quality seed saving is allowing seeds to mature fully before harvest.
Bean Seeds
Snap beans for seed: Let pods remain on the plant long after you would harvest for eating. Pods should become dry and papery, turning tan, brown, or straw-colored depending on variety. Seeds inside should be hard and rattle when you shake the pod.
In Santa Cruz County, this typically means an additional 4 to 6 weeks beyond the snap bean harvest stage. Pods left from mid-season harvests are usually ready by early to mid-fall.
Dry beans: Since you are already growing these for dry storage, the process is the same. Harvest when pods are completely dry and papery.
Coastal challenge: Fog and fall moisture can prevent complete drying on the plant. If pods are nearly dry but weather threatens, pull entire plants and hang them upside down in a covered, well-ventilated location (garage, covered porch, greenhouse) to finish drying.
Pea Seeds
Snap and snow peas for seed: Stop harvesting from seed-saving plants when pods reach eating stage. Let remaining pods dry completely on the vine. Pods should become papery and tan, with hard, wrinkled seeds inside that rattle when shaken.
Shelling peas for seed: Same approach. Allow pods to dry completely on the plant.
Peas typically mature seeds faster than beans since they produce earlier in the season when more dry weather is available.
Signs Seeds Are Ready
Ready to harvest:
Pods completely dry and papery
Seeds hard (cannot dent with fingernail)
Seeds rattle inside pods when shaken
Seeds have fully developed color for the variety
Not ready:
Pods still pliable or green
Seeds soft or can be dented
Seeds still have greenish tinge
Moisture visible when pod is opened
Harvesting and Processing Seeds
Harvest Method
Hand harvesting: Pick individual dry pods from plants and place in paper bags or baskets. This works well for small quantities and allows you to check each pod.
Whole plant harvest: For larger quantities or when weather threatens, pull entire plants (or cut at soil level) and hang upside down to finish drying. Harvest seeds once everything is completely dry.
Threshing (Removing Seeds from Pods)
For small quantities, simply open pods by hand and remove seeds. For larger amounts:
Bag method: Place dry pods in a cloth bag or pillowcase. Beat gently with a stick or stomp on the bag to break pods and release seeds. Then separate seeds from debris.
Walking method: Spread dry pods on a tarp and walk on them (wearing clean shoes) to break pods open.
Winnowing (Separating Seeds from Chaff)
After threshing, you will have a mix of seeds and pod fragments. To separate:
Wind winnowing: On a breezy day, pour the mixture slowly from one container to another, allowing wind to blow away lighter chaff while heavier seeds fall into the catching container.
Fan winnowing: Use a fan on low setting to create airflow. Pour the mixture in front of the fan, catching seeds in a container while chaff blows away.
Hand sorting: For small quantities, simply pick out seeds by hand.
Drying Seeds for Storage
Even seeds that feel dry may contain too much moisture for safe long-term storage. Additional drying ensures seeds store without molding or losing viability.
Drying Methods
Air drying: Spread seeds in a single layer on screens, paper plates, or newspaper in a warm, dry location with good airflow. Stir occasionally. In dry weather, 1 to 2 weeks is usually sufficient.
In Santa Cruz's coastal humidity: Air drying takes longer here than in drier climates. Allow 2 to 3 weeks, and consider using a dehumidified room or desiccant packets.
Desiccant drying: Place seeds in a jar with an equal weight of silica gel desiccant packets. Seal and leave for 1 week. The desiccant absorbs excess moisture.
Testing Dryness
Bite test: Completely dry beans and peas are extremely hard. You should not be able to dent them with your teeth.
Hammer test: A fully dry bean shatters when struck with a hammer rather than squishing or bending.
Target moisture: Seeds should contain less than 8% moisture for safe storage. Home gardeners cannot easily measure this, so use the physical tests above.
Storing Seeds
Proper storage maintains seed viability for years.
Storage Conditions
Cool: Store at 40 to 50 degrees F if possible. A refrigerator works excellently. At minimum, avoid hot locations like garages or sheds in summer.
Dry: Low humidity is critical. The combination of cool and dry dramatically extends viability.
Dark: Light degrades seeds over time. Store in opaque containers or in a dark location.
Storage Containers
Best: Glass jars with tight-fitting lids (Mason jars work great) Good: Sealed plastic bags inside rigid containers Acceptable: Paper envelopes inside a sealed container
Add a desiccant packet to your storage container to absorb any remaining moisture. Indicate-type silica gel (which changes color when saturated) lets you know when to replace or regenerate the desiccant.
Labeling
Always label seeds with:
Variety name
Year harvested
Any notes (excellent producer, early bearing, etc.)
Labels fade and memory fails. Good labeling prevents confusion years later.
Viability Expectations
Properly stored bean seeds: 3 to 4 years (some viability may persist longer) Properly stored pea seeds: 3 years (viability declines faster than beans)
Poor storage conditions (warm, humid) dramatically reduce these timeframes. Seeds stored in a hot garage may lose viability in one year.
Testing Seed Viability
Before planting saved seeds, especially older ones, test germination to know what to expect.
Simple Germination Test
Count out 10 seeds (or 20 for more accuracy)
Place seeds on damp paper towel
Fold towel over seeds and place in plastic bag, leaving bag slightly open for air
Keep in warm location (70 to 80 degrees F)
Check daily, keeping towel moist but not waterlogged
Count germinated seeds after 7 to 10 days
Interpreting results:
80 to 100% germination: Excellent, plant at normal rate
60 to 80% germination: Good, plant slightly thicker to compensate
40 to 60% germination: Fair, plant twice as thick
Below 40%: Poor, consider using fresh seed
Maintaining Variety Purity
If you want to maintain a variety true to type over many years:
Prevent Crossing
While crossing is rare in beans and peas, you can further reduce chances by:
Growing only one variety of each species for seed (grow others for eating only)
Separating seed-saving plants from other varieties by at least 10 to 20 feet
For favas, use 50+ feet separation or stagger flowering times
Rogue Off-Types
Each year, remove any plants that do not match variety characteristics before they flower. Off-type plants may be crosses from previous years or genetic variations.
Introduce Fresh Genetics Occasionally
After many generations of saving from a small population, varieties can lose vigor due to inbreeding. Every 5 to 10 years, consider introducing seeds of the same variety from another source to refresh genetic diversity.
Seed Saving by Type
Bush Snap Beans
Allow 3 to 4 plants to remain unharvested for seed. Let pods mature fully (4 to 6 weeks past eating stage). Harvest when pods are dry and papery. Yields 1/4 to 1/2 pound of seed per plant.
Pole Snap Beans
Same approach as bush beans, but with higher yields per plant. Designate a section of your trellis for seed saving and do not harvest any pods from these vines for eating.
Dry Beans
Already grown for dry harvest, so seed saving is straightforward. Reserve your best pods from your healthiest plants for next year's seed rather than for cooking.
Snap and Snow Peas
Allow pods from 6 to 10 plants to mature past the eating stage. Peas dry on the vine more easily than beans because harvest season is earlier (more dry weather). Expect 1 to 2 ounces of seed per plant.
Fava Beans
Let pods dry completely on the plant until black and papery. In our humid spring conditions, you may need to finish drying under cover. Favas have higher outcrossing rates, so maintain some distance between varieties.
Troubleshooting Seed Saving
Seeds Molding in Storage
Cause: Seeds not dry enough before storage, or storage location too humid Solution: Dry seeds more thoroughly. Add desiccant to storage container. Move to drier storage location.
Low Germination Rate
Causes: Seeds harvested before fully mature, improper drying, poor storage conditions, seeds simply old Solutions: Wait for complete maturity before harvest. Ensure thorough drying. Store cool and dry. Test viability before planting large quantities.
Seeds Cracked or Split
Cause: Often happens during threshing if seeds are too dry, or from freeze/thaw cycles in storage Solution: Thresh more gently. Avoid freezing unless seeds are very dry. Cracked seeds can still germinate but may be more prone to rot.
Off-Type Plants in Next Generation
Cause: Crossing with nearby variety, or genetic variation Solution: Rogue off-types before flowering. Increase isolation distance. Accept that some variation is normal.
Frequently Asked Questions
How many plants should I save seeds from?
For casual home use, 4 to 6 plants provides plenty of seeds. For maintaining genetic diversity long-term, save from 10 to 20 plants minimum.
Can I save seeds from hybrid varieties?
You can, but offspring will not be identical to the parent. Hybrids (F1) produce variable offspring, some resembling each parent and some intermediate. For consistent results, save seeds from open-pollinated or heirloom varieties.
My bean plants had rust or powdery mildew. Can I still save seeds?
For leaf diseases like rust and powdery mildew, seeds inside pods are usually unaffected. However, I recommend saving seeds only from your healthiest plants. For seed-borne diseases (bacterial blights, anthracnose), do not save seeds from affected plants.
How can I tell if my saved seeds are still good?
Do a germination test: place 10 seeds on a damp paper towel in a plastic bag. Keep warm and check after 7 to 10 days. Count how many sprouted to estimate viability.
Why did my saved bean seeds look different from the original variety?
Possible crossing with another variety, though this is rare. More likely, the original seeds were themselves crosses or the variety naturally has variation. If you want pure strain, rogue out plants that do not match variety descriptions before they flower.
Can I freeze bean and pea seeds for long-term storage?
Yes, if seeds are very dry (below 8% moisture). Freezing moist seeds damages them. For home gardeners, refrigerator storage is usually sufficient and avoids the moisture risk.
Free Resources
Download these helpful guides from Your Garden Toolkit:
Seed Starting Guide: Complete guide to starting seeds, including your saved seeds.
Seasonal Planting Calendar: When to plant your saved seeds next season.
Bean and Pea Seed Saving Guide
Easiest seeds to save for next year's garden
Mark 3-5 of your healthiest, most productive plants early in the season. Save seeds only from the best performers.
Stop harvesting those plants. Let pods turn brown, dry, and papery on the vine. Seeds should rattle inside when you shake them.
Crack open dry pods and remove seeds. Spread seeds on a screen or paper towel for 1-2 weeks indoors to ensure complete drying.
Place in labeled paper envelopes or glass jars. Store in a cool, dry, dark spot. Bean and pea seeds stay viable for 3-4 years when stored properly.
