Seed Saving 101

How to Save Seeds:  A Practical Guide for Home Gardeners

You’ve grown a tomato you love. Are you wondering if you can save its seeds to sow next year? Hybrids, heirlooms, open-pollinated varieties. It’s no wonder growers get confused about which seeds they can save, and which will not produce the crop they’re expecting. 

Our guide breaks down which seeds you can save, how to do it best, and which to buy fresh each season. Setting realistic expectations will prevent disappointment when seed-starting time rolls around. 

Proper seed storage helps gardeners:

• Preserve their favorites

• Save money when ordering seeds

• Build more resilience in their gardens year after year

• Adapt seeds to your climate 

• Promote biodiversity 

• Create personal gifts

• Pass down legacy varieties 

Seed Saving Basics Every Gardener Should Know

What Does It Really Mean to Save Seeds?

The type of seeds you choose for your garden will depend on your needs, setup, and future goals. If saving seeds is a significant goal, choose heirlooms and open-pollinated seeds. Farmers often choose mostly hybrid seeds for their high productivity and reliability. 

Open-pollinated (OP) seeds: 

• Rely on insects, rain, and wind for pollination (some may be self-pollinated)

• Create a replica of the parent plant next season

• Are genetically diverse 

• Feature the best qualities like heat and cold tolerance, uniformity, and flavor 

Heirloom seeds: 

• Passed down by generations of families and originating all over the world

• May carry family stories 

• All are OP

It’s fun to sprinkle new heirloom varieties into the garden each season. They produce beautiful colors and unique old-timey flavors.

Hybrid (F1) seeds: 

• Were created in a lab for improved crop production, disease resistance, and flavor 

• More productive than heirloom and OP varieties 

• Are not GMOs!

• Saved seeds produce one of the two parent plants, not the plant they came from 

• Are purchased new each year for consistency and reliability 

Choose hybrids if you: 

• Rely on your garden to put up food for your family for winter

• Need consistent production for a farmer’s market or CSA

• Require disease and pest resistance

Know Before You Save: What Makes a Good Candidate Crop

Save OP or heirloom seeds for your first few seasons. Get those easy wins to boost confidence and manage expectations. You’ll learn more each season, and can consult your notes if questions arise. 

Next, we’ll discuss specific crops ideal for beginners and other seeds that require some experience for success. 

Seed Saving by Crop Difficulty

Easiest Crops to Save Seeds From (Great for Beginners)

If you’re new to saving seeds, start with the tried-and-true self-pollinating plants.

• Legumes can be left in place on the plant while drying, so it takes minimal effort.

• Lettuce will produce tall stalks with flowers if left in place. The flowers will eventually produce seeds, and the stalks can easily be harvested and dried. 

• Select the healthiest tomato fruits with uniform shape and size. Harvest them at full ripeness, leaving them on the vine slightly longer than you would for consumption. 

Intermediate Crops: Worth It With a Bit of Effort

These crops may cross-pollinate, but you can limit this by isolating the blooms. 

• Peppers

• Squash 

• Cucumbers 

These methods of isolation can prevent cross-pollination:

1. Distance: Unless you have several acres of gardens, separating crops over many miles may not be realistic. However, if you do, and want to try this method, separate them according to the recommended distance for that crop. Wind, insects, and rain can help pollen travel to a plot ten feet away, but it’s less likely to travel a ½ mile. 

2. Containment: Use bloom bags or insect netting to prevent insects and wind from pollinating. 

3. Timing of Flowering: When growing more than one variety of the same crop, plant them so their flowering does not overlap. 

Find further discussion of these methods and more on Seed Savers Exchange: Isolation Methods.

Advanced or Not Recommended for Most Home Gardeners

Once you’ve mastered seed-saving techniques, move on to these more advanced seeds. These easily cross-pollinate, leading to unpredictable crops next season. In order to save reliable seeds, they require extensive isolation. 

• Corn 

• Carrots 

• Brassicas 

• Beets (biennial) 

• Squash and pumpkins

Don’t beat yourself up over having to shop for some seeds. Save the ones you have success with, and support reputable seed companies for the rest. 

Step-by-Step: How to Save Seeds From Common Crops

Tomatoes

Experts recommend fermenting seeds before storing them to reduce the risk of disease and prevent rot. However, it’s something you can work up to, as it’s not entirely necessary and seed will likely just take longer to sprout the next year. 

Seed fermentation removes the thick, gelatinous coating of wet seeds. This outer coating can promote mold growth and harbor pathogens. This step is crucial for cucumbers and tomatoes. 

1. Combine the pulp and seeds in a jar of fresh water for several days. This process breaks down the outer coating, which kills pathogens, and improves storability and seed viability. 

2. Swirl the water around once daily and keep the jar in a warm spot, between 72°F and 86°F (22°C and 30°C).

3. It’s normal for mold to form and the jar to become a bit stinky. Do not allow seeds to sprout. Discard any seeds that float, as they are likely unviable. 

4. Strain the seeds from the water after two to three days. Rinse them thoroughly and ensure any mold signs wash away. 

5. Spread them onto a clean plate, baking sheet, or mesh tray. For tiny seeds, you may want to use a paper towel on the tray. 

6. Place the seeds in a well-ventilated area, using fans if needed. They may take a week or more to dry completely. 

To store tomato seeds without fermenting them first, lay the freshly harvested seeds flat on a paper towel and let them dry. Store them this way, allowing the gel coating to dry up on the towel. When it comes time to plant, simply tear the paper towel and seed off together, and sow it. Be sure to allow them to fully dry before storing, as this method slightly increases the risk of mold. 

Peppers

Leave peppers on the plant to mature. Allow the fruit to wrinkle a little before harvesting. Peppers don’t have an outer coating, so fermenting is unnecessary. They’re considered dry seeds vs. wet seeds. 

Cut open the pepper, remove the seeds, and rinse them, if desired. Place them in a safe place to dry for several days, up to ten. You can also use a dehydrator on the lowest setting for a few hours. Seeds should snap or cut in half when they’re dried, rather than bend. Count the seeds and store them in a paper baggie or inside a glass jar with an airtight lid. 

Cucumbers

Ensure cucumbers have fully ripened before saving their seeds. Allow the fruits to bloat slightly and yellow on the vine before harvesting. This method ensures that seed maturity has reached its peak.

Follow the steps to ferment your cucumber seeds (as discussed above). Their thick, gelatinous coating can, if left intact, promote mold growth. They’re considered wet seeds. Scoop the fruit's innards out and place them in a jar filled with fresh water. Ensure all the seeds are covered, then cover with a cloth. Give it a shake or stir every few days. Proceed as you would with tomatoes. 

Beans & Peas

Beans and peas are the simplest seeds to save and store. Just leave the pods on the plant until they’re visibly dry and brittle. They may even make a rattling sound in the wind. The plant itself may have died mostly back, and the leaves will be yellow.

Harvest them before rain or snow to prevent mold. To remove beans and peas from the husk, use one of the two methods below: 

1. Crack the pod open and remove the seeds by hand.   

2. The bag or pillowcase method: Toss pods inside and whack the bag/pillowcase on the ground until the seeds are out of the pods. Remove the pods, husks, and chaff, leaving the seeds behind. 

Removing seeds from the husks is a fun exercise you can do with kids while watching a movie or around a fire. It will seem less daunting when you do it together! 

Bootstrap tip: If some pods are still green, harvest the entire plant. Hang it in a dark, dry place to finish drying, and remove the pods for storage. This is a solid option if rain or snow is heading your way before they’ve all dried. 

Annual Flowers 

Love growing annual flowers? Saving seeds for so many of them is simple and rewarding. They dry easily on the plant, produce large seeds, and store well. 

Start with these six:

1. Calendula 

2. Nasturtium 

3. Zinnias 

4. Sunflowers 

5. Cosmos 

6. Marigolds

If you have to harvest them before the seeds are dry, hang them upside down inside a brown paper bag. To remove the seeds, run your hand gently over the flower head to coax them out. Pull large seeds, like sunflowers, out by hand.

How to Test Saved Seeds for Viability

Germination Testing at Home

Perform germination tests on seeds in the fall or winter, once they’re thoroughly dried. Don’t wait until spring when seed companies might be sold out of your favorite varieties.

Test the viability of your seed lot by doing a germination test. Sacrifice 10-20 seeds by placing them into a damp paper towel, then into a plastic bag. After a few days on a heat mat or in a warm place in your home, count how many seeds germinate. The percentage of seeds that crack open is your germination rate. Note this on your seed packet so you don’t forget. 

Bootstrap tip: If you don’t have a sunny windowsill, place seeds in a 1020 tray and cover it with a humidity dome. Place the tray on a heat mat or near a heater to assist with germination. Spritz the towel with water from a spray bottle as needed to prevent the seeds from drying out. 

The results will let you know if you need to order seeds and, if so, how many. Have a ton of the same variety? Gift them to friends and neighbors or share them with a local seed-saving group. Check with your local library to see if they have a seed-sharing program.

What to Expect from Different Crops

Many seed companies add germination rates on the seed package, so you know what to expect. We recommend doing the same with your homegrown saved seeds. The lot is much smaller, so the rates won’t be exact. Noting the rate will ensure realistic expectations come seed-starting time. 

The Iowa State University Extension indicates that a germination rate of 50% or lower is not worth keeping. But if you have emotional or familial ties, save them anyway; just know you won’t see much germination. 

The chart below assumes that the seed saver has properly dried their seeds and stored them in a dry, dark area. 

Note that germination rates decrease each year, even under ideal conditions. 

Storage Tips: Keeping Saved Seeds Safe and Viable

As a reminder, seeds must be thoroughly dry before storage. Moisture will wreak havoc on the viability and can cause a total loss of the lot and possibly those nearby. 

Seeds need cool, dry, and dark conditions to survive. Create a space where the temperature remains between 32°F and 41°F (0°C to 5°C) if you can. A semi-heated garage or basement works well. Bootstrap tip: A mini fridge makes an ideal seed storage area! 

Airtight containers are crucial. If you have various types of seeds in paper seed packets, store multiple in a glass jar with a well-fitted lid. Add a desiccant packet to each to absorb excess moisture. Clearly mark each seed packet with a variety and date. Slip a plant label inside each bag to stay organized. 

Save more seeds than you think you will use next season, so you have plenty to perform a viability test. Remember to clearly mark each packet with the year so you can refresh your batches as needed. If you haven’t used all the seeds after three years and the germination rate is below 50%, toss them to the birds. 

Common Mistakes to Avoid When Saving Seeds

Saving Hybrids Without Knowing It

Depending on the breeding method, hybrid seeds may or may not grow into plants that produce fruit. You’ll often get fruit, but there’s no guarantee the production will be good or that the fruit will be tasty. 

Skipping the Drying Process

Seeds that contain moisture will mold and rot in storage. If you get lucky and they don’t rot, their viability will likely decrease. Moisture is the enemy of successful long-term storage. If you have doubts about the moisture level in your seeds, let them dry just a bit longer before storing them. 

Poor Labeling or Organization

Poor labeling will lead to confusion in the spring. You might be able to tell a cucumber seed from a kale seed, but if you have several varieties of each, you won’t know which is which. 

It’s a classic mistake that we’ve all made, and one of the most avoidable. Don’t have labels or a label maker? Grab whatever you have on hand. Be sure to use a permanent marker so your notes don’t wear off. 

Not Testing Seeds Before Planting

Knowing if and how viable seeds are helps us decide how many seeds to plant in the spring. Sowing unviable seeds leads to wasted soil, energy, and time. If you do one thing this winter, do a viability test! 

Bootstrap tip: Healthy soil is the building block of a healthy garden. Check out our guide to boost soil fertility to kick off your season right. 

Tools & Supplies for Successful Seed Saving

Must-Have Tools

You can successfully save seeds with items you likely have at home. But if you’re saving large lots of them, make your life easier and stay organized by snagging these must-haves. 

• Jars, empty vitamin bottles, or paper envelopes 

• Seed starting trays

• Humidity domes

• Seedling heat mats

• Plant labels

• Spray bottles

Why Professional Tools and Supplies Matter for Testing, Storing, and Next Season’s Starts

Professional tools will get you more consistently reliable results. Investing in high-quality supplies will cost you more up front, but it’s worth it in the long run. Once you’re a master seed-saver with a stellar organization system, you can create your own seed library and share the wealth with your community. 

FAQs for Seed Saving for Home Gardeners

Can I save seeds from store-bought vegetables?

You can save seeds from any vegetable. If you aren’t sure of the exact variety and seed type, you risk mystery results. 

How do I know when seeds are ready to harvest?

Readiness varies across crops and seed types. Crops whose product does not contain seeds, such as lettuce, will need to bolt to produce seeds. Tomatoes, cucumbers, and peppers can be harvested at maturity, dried, and stored correctly. Allow legumes to dry on the plant and harvest them later in the season. 

Do I have to ferment tomato seeds?

Fermenting seeds:

• Removes the gelatinous outer layer

• Reducing the risk of rot and disease

• Potentially improving germination rates

It’s not required, but many experts recommend it. 

Can I save seeds from hybrid plants?

You can save any seeds, but hybrid plants will not produce replicas the following season. Their seeds will produce plants with traits randomly inherited from their parents. The yields, size, flavor, and productivity will be unpredictable and inconsistent. 

How long will saved seeds last?

When dried and stored properly, seeds can last 1-5 years or more. Seeds can last up to ten years under ideal conditions, but germination may be spotty. Check out this article from Michigan State University about plant biologists who dug up seeds buried nearly 150 years ago!

What’s the best way to test seed germination?

Add seeds to a damp paper or cloth towel. Place the towel inside a plastic bag and let it sit on a heating mat or in a sunny window for several days. Check to see how many seeds have germinated within the standard window for that variety. Divide the number of germinated seeds by the number you added to the towel for the germination rate. If you tested 10 seeds and 8 germinated, your rate is 80%. 

How do I label and organize saved seeds?

Use a permanent marker and colored plant labels to mark seed variety and the year you harvested them. 

Which seeds are easiest for beginners to save?

Peas, beans, lettuce, and self-pollinated tomatoes are great for beginners. 

Can I skip isolation and still save good seeds?

If you’re okay with experimental results, save them and see what grows! 

What’s the fastest way to dry seeds at home?

Large seeds dry well in shallow mesh trays. You can also place them on a cloth towel in a well-ventilated area with fans or in a dehumidifier. Use a fine-mesh strainer or a sieve for small seeds. No matter the method, be sure they don’t become overly dried out or brittle, which could lead to unviability.