Saving Tomato Seed

This post will focus on how to save tomato seeds.  In order to learn which plants are best to save seed from, be sure to read this article!

Tomato seeds are one of the few seeds that can be saved when your tomato is nicely ripe – and still edible.  You want it to be on the verge of being over-ripe, but not inedible.  These plants are self pollinating, and due to flower structure (exposed stigmas) the ability for insects to cross pollinate is extremely limited.  There are three types of tomato plants that may still cross with one another: currant tomatoes, potato-leaved varieties (those with a smooth leaf edge, vs. a serrated edge), and any fruits that are formed from double-blossoms on beefsteak types (do not save seed from double-fruits).  If you choose to grow one of each variety, you should have no problem with cross pollination.

Pick and wash your tomatoes first.  As you are preparing to eat your tomato, just squeeze the tomato seed “guts” into a clean jar.  Be sure to label your jars and use one jar per variety if you are saving seed from more than one variety.

Fill each jar with water and stir to help separate the seeds from the gel surrounding them.  They won’t separate immediately, but you can get a lot of debris to rise to the top of the jar after stirring and letting it sit.  Seeds will set to the bottom, while bad seeds and debris will rise.  Pour off this debris, replace the water, and allow the seeds to sit at room temperature overnight.  Stir a few times per day, but allow the debris to stay on the top.  It will eventually start to mold, and this is actually encouraged.  The fermentation will help kill seed-borne tomato diseases.  Your tomato mixture will begin to stink, so you may wish to move these to a less populated area of your house or garage or other space, but keep it in warmer temperatures.

Once the mold covers the top  surface of your seeds, or you notice bubbling, you may stir the debris, let it sit for a few moments, dump off mold and debris, refill with water, stir, and allow seeds to fall again.  Pour off debris again, replace water, stir again.  By this time, the seeds should be well cleaned and ready to dry.

Using a fine-mesh strainer, pour the remaining clean water and seeds into the strainer, then place on a screen to dry.  You can create a drying tray by building a small wooden frame and stapling screen on the bottom.  You may also dry on a ceramic or glass plate but remove excess moisture with a paper towel before letting them dry.  Don’t dry seeds on paper towel or cloth, as removing them will be too hard.  Stir the seeds a few times per day to eliminate sticking and clumping.  Don’t forget to label the screen with the variety, because most tomato seeds look the same.  Don’t dry the seeds in direct sunlight, or in an oven or dehydrator.

Save the seeds in an airtight container and stored in a cool, dry area.  They can last 4-10 years with proper storage.

Don’t save any old seed!

This time of year there are plenty of seeds everywhere. Your broccoli, if left in the ground, has sprouted flowers which have turned into seed pods. Maybe there are some cucumbers that were oddly shaped that were left behind and now have yellowed and are beginning to dry out. Perhaps you lost a zucchini out there and it’s now turning yellow and well beyond the acceptable period for consumption. Maybe your radishes have produced seed pods that are drying. Being new to seed saving, you are interested in saving all the seed you can to reduce your costs next year, right? So out to the garden you go, collecting seeds for next years garden.

Please don’t. I don’t say this to burst your bubble, but to prevent you from having a less than desirable outcome next season. Every year I see people excitedly saving seed from everything in their garden, but this is the only time of year they have even thought about saving seed. Saving seed now, without any prior planning, will not yield the results you are hoping for (in most cases). There are some fairly foolproof plants you can save seed from successfully such as tomatoes, beans, peas and lettuce. They have different methods for harvesting and cleaning the seed, which I will be covering shortly. Saving seed is an intentional activity that should be included in your garden planning- well before any seeds have been started. And there are things to think about for long-term success.

Let me tell you why.

First, the type of seed you originally planted is perhaps the biggest determining factor to seed saving success. The goal here is to grow plants true-to-type, which means if you planted a Roma tomato, you want to grow a Roma tomato with the exact same qualities, right? You are counting on certain characteristics to show themselves again. Do you remember exactly what type of seed you planted and are trying to save? Are you certain that what you planted was open pollinated or heirloom variety and not a hybrid? Hybrid seed is a crossbred between two parent plants. That means if you save that seed, what you will grow next year will not be true-to-type. It may grow. It may even produce. But it won’t be what you expected and might even be disappointing.

Second, do you remember the variety? Us gardeners like to plant a lot of varieties of the same plants in our garden. But knowing what variety you planted is really important. Different varieties have different qualities that you want to keep growing true-to-type and it is important to be able to identify varieties to ensure quality and characteristics are what they should be.

Third, Did you do anything to prevent cross pollination? Some plants are self pollinating, but many are not. Wind and insects are responsible for the pollination – and that could include carrying pollen from different varieties which would then make the seed from that produce a hybrid. The seed will still look exactly the same, but when you plant it, you may notice different characteristics. Even self pollinated plants can occasionally be cross pollinated by insects. Methods to prevent cross pollination between varieties include caging, netting (hand pollination by you may be necessary), blossom bagging, time (if your season is long enough and your varieties allow for it, you can plant one variety early and plant the next variety when the first variety is blooming, so the insects only pollinate one variety at a time), and isolation distance. Isolation distances are often quite out of reach for a home gardener though, so I recommend other methods of isolation. Also keep in mind, even if you are being careful to only grow vegetables that will not cross pollinate, your neighbors may be growing something that will. Some people prefer to keep varieties separated on their side of their property with pollinator distractions in the middle and/or tall buildings or landscape features to interrupt the flow of wind. Both of these are said to possibly prevent cross pollination as insects will drop their pollen elsewhere (with other blooming distractions) before making their way back to the other side of your garden, and buildings or even tall plants like sunflowers, can interrupt windflow and prevent cross pollination there. Another point related to cross pollination is that some weeds from our yard, the neighbors or a nearby field will cross pollinate with certain plants in our gardens too!

Fourth, Are you saving seed from a variety of plants that are growing true-to-type? Did you save some of your very best vegetables for seed saving or did you eat them all? As a seed saver, it is important to pay attention to the plants we wish to save seed from all season, not just at harvest time. And, we don’t want to leave all of the smaller, poorly shaped produce to save seed from – nor do we want to save just the biggest and the best. In fact, the plants that we wish to save seed from have many characteristics that are very important that go beyond the actual vegetable its self. Plants that bolted early, developed blight, have oddly shaped fruit, have smaller leaves, slower growth – these are all characteristics you don’t want to encourage in the following generations. However, a plant with good vigor, one that is slow to bolt, has insect resistance, stockiness, hardiness, uniformity, and earliness are characteristics that you should want to encourage. Select seed to save from those types of plants.

Fifth, Did you plant enough for genetic diversity? Population is very important, but not many people think about it. This is another important factor that needs to be considered before you begin planting seeds in the spring. To avoid decreasing the genetic diversity within a crop, you should save seed from as many plants as possible that have the very best characteristics (remember, this goes beyond the vegetable its self). Maintaining genetic diversity within your plant population is important for continued evolution and adaptation to changing conditions in their environment. So, instead of looking to save seed only from the plants that produced the biggest and best vegetables, aim to select a large number of seeds from plants that have the qualities desired in the variety you are growing. Even though it may not have produced the biggest and best produce on every plant, perhaps the plants are still true-to-type and display the characteristics that you wish to encourage. There are a minimum number of plants that should be grown of certain varieties to ensure genetic diversity. Genetic diversity probably won’t even be something that will affect you for at least a few generations – but ensuring it now will pave the road for your success years from now. If your space is limited, maybe you could form a group with neighbors and share the growing? How neat would that be!

Some plants don’t set seed until the following year. For those, such as beets and carrots, you will need to keep them alive through the winter. In our climate you would need to dig them out and keep them alive in your house before replanting the following year.

These are just a few questions to ask yourself before you save that seed – some vegetables do self pollinate and the risk of cross pollination is low, but as you can see from above there is much more to seed saving than just the seeds. A lot of observation through the entire growing season is necessary for best results, and planning prior to planting to allow for proper isolation and population sizes is very important as well.

Whatever seed you do save, be sure to label it!! I don’t mean simply ‘tomato’ but, include the variety.

If you are certain you planted open pollinated or heirloom seeds, and you want to try seed saving just to try the process (and have a good chance at success), you can start with common beans, peas, tomatoes and lettuce. Heck, you could try saving the seed of anything really, but please do so knowing that it may not produce the results you are hoping for. I just wanted to give you some questions to ask yourself before you run out to save seed that might not end well for you.

I will be covering much more about seed saving and teaching a class sometime later in the winter, giving you plenty of time to think about the important factors and to help you with your spring planting. I have been saving seed in my garden on many things for many years and while it has been a little extra planning, planting and observing, it has helped preserve varieties I enjoy, saved a lot of money not having to buy the seed, and has given me another step toward self sustainability. I really enjoy it, and I hope you will, too.

Here is an incredibly helpful chart on seed saving that covers isolation distances, population numbers to preserve genetic diversity, pollination methods and much more. Print this, you will want to refer back to it often.

Saving Common Bean Seeds

Here are instructions for saving common bean seeds. What are common beans? snap beans, string beans, wax beans, shell/dry beans, kidney beans, and most garden beans.

If you are growing green beans or other garden beans, by now you may have some left on the vine that have gotten too big to enjoy eating. If you planted an open pollinated or heirloom variety and want to save the seeds to plant back next year, you’re in luck! Let those beans continue drying on the vine until they are dried out and you can hear them rattling inside the pods. Choose to save seed only from plants that have grown well all season and appear true-to-type.

If you are having an exceptionally wet fall or a frost is looming and your plants are still green, you could pull the plants and allow them to dry indoors by hanging them or laying them in a well ventilated area. If you lay them somewhere, turn them often. Hanging is preferred. Leaving the pods attached to the plant allows the pods to soak up energy from the plant for a few extra days, which will result in better quality seed. After a few days of hanging, you may remove the pods and continue to let them air dry, or leave them right on the vine.


Once your seeds are dry and ready for harvesting, you need to remove them from the pods. This can be done in several ways – place them in a pillowcase and tie it shut, then throw it around the house like a hot potato with your kids. Or jog in place on it. Or beat it with a bat. Once the seed is dry, the pod will fall off in pieces with a light touch, so your goal here is to crush the pod so the seeds fall out. This doesn’t mean you need to drive over the pillowcase with a vehicle or anything extreme, as you might with trying to crack walnuts. To remove the broken pods, or chaff, you will want to set yourself up in the area of a light breeze outdoors or in front of a fan, and pour the pillow case contents into a bowl or container below. Ideally, with the right speed breeze, the chaff will float out and the seeds will fall into your container below. Do this as often as needed to clean the seed.

Another option that might save you the extra step of sorting the undesirable seeds from the bunch is to simply open each pod individually and drop the seeds into a bowl. You will get pretty good at determining what seeds can get dropped in, and what should be discarded. You will want to discard any seed that is not true-to-type – small, shriveled, or any with characteristics that differ from the rest.


Store beans in a cool, dry, dark area. Common beans will retain 50% germination for four years.


  • Always save seed from healthy plants that appear true-to-type and have produced a large harvest.
  • Leave pods to dry on the vine as long as possible – ideally until completely dry.
  • If you are unsure if the seeds are dry and ready for storage, place a few on a solid surface and strike with a hammer. If it/they shatter, they are dry.
  • Don’t grow different varieties right next to each other. While beans often do not cross pollinate (it IS possible, but rare), having varieties separated will help give another layer of protection.

Save seed from grocery produce? Maybe not.

Saving seed can be a truly enjoyable – and frugal – way of growing a garden… But there are some things to know. I often see well meaning gardeners suggest saving seed from storebought produce such as tomatoes, green peppers, green beans, squash, etc. While this seems like it would be a really great idea, it isn’t as simple as drying seed and planting it next year. Growing vegetables for saving seed is different than growing vegetables to eat, but they can be done together in the same garden with proper precautions – but the key here is that you should definitely grow them yourself.

Seed saving can seem a little complicated at first once you realize that many plants cross pollinate (resulting in seed that won’t grow true), and as a result, must be isolated during the flowering phase of growth (and in many cases, hand-pollinated by you). Saving seed from some vegetables requires fermentation, saving seed from others requires the vegetable be over-ripened on the vine, and yet other seeds destined for saving should be dried on the vine.

Here are some reasons against saving seed from grocery store purchased produce:

  • When you buy grocery store produce, you usually won’t know if the variety is hybrid or open pollinated; hybrid produce will not produce seed that will grow true. That means if you save seed from a hybrid tomato, it will not grow to be just like the one you saved seed from. It may sprout, but never grow fruit, but if it does grow fruit it likely will not be like the fruit you saved it from. You likely may not be able to find out the exact variety that was grown, either.
  • Consider also that most of our produce is brought in from far away, and growing conditions are very different all over the country. What grows for one farmer in California, won’t grow well for us here. I learned that the hard way trying to grow garlic from the store. Chances are good that on many things, we won’t even be able to determine the variety. If it is an open pollinated variety, you won’t know if it has been isolated to prevent cross pollination (farmers growing food for the market won’t isolate varieties as a general rule – their end goal is produce, not seed from that produce).
  • You want to be selective with what produce you save seed from. You don’t have that option to pick and choose from the best representations a garden has to offer when it comes to vegetables purchased from the store.
  • With all of the varieties you could grow, ask yourself if the tomato you bought from the store has the qualities you want in your own garden – is that tomato you want to save seed from really flavorful enough to chance saving seed from?   you can grow varieties with more flavor, that (depending on variety) can be saved easily. You can also find other qualities in seeds that are important for you, your growing location, and your preferences. Produce grown commercially is grown to benefit the farmer, whether that may be ripening early, growing thicker skins to withstand shipping, uniform size, resistance or tolerance to certain things – these things may not be as important to us as a home gardener. But, taste and the opportunity to pick color, shape, or other neat options may be.
  • You can’t see the plant the produce came from. A key element to saving seed is being able to select produce that is growing true to type, that is growing from a plant that is growing true to type. What you save is what you grow. Without being able to see the parent plant and watch it’s growth and see its characteristics, you may be saving seed from a plant that has qualities you don’t want to encourage.
  • For best taste and nutrition, vegetables should stay on the vine as long as possible and harvested at the peak of ripeness – and for the few produce varieties that you can save seed from when they are ripe and ready to eat, you want the same end goal (ripe and fresh off the vine because that is when the seed is mature enough for saving).  Produce that was picked before being ripe will not have seeds that are mature and your attempts at seed saving may not be successful, even with heirloom varieties.  Any other produce used for seed saving must over-ripen on the vine or even dry on the vine before it’s seed is considered viable and ready to harvest – you’d never find that for sale in a grocery store. 

I want to see you succeed at gardening! Seed packs can now be purchased for 25 cents to a buck per pack now, instead of the usual $2+. Set yourself up for success by using methods that have been established as true. If you still want to try saving seed from grocery store produce, by all means, give it a shot! But if you aren’t successful, please don’t let that break your gardening journey. Learn more about seed saving here on this post.

What’s involved in saving seed?

This is just an overview. I will get into the nitty-gritty of seed saving over time.

As a backyard grower, we can grow plants for flavor, texture, color and any other attributes that we want because we can grow many different varieties. We have many options as far as variety when it comes to ordering seeds from a seed company – but our options used to be huge. Each year, family heirlooms are lost forever as farmers and families plant the last seeds they have, then they cannot find anyone else to carry on the variety they have grown for so long. This is where seed saving comes in – when we are successful ourselves we can keep our favorites varieties from extinction.  There are plenty of hybrids that are excellent for the backyard grower, too, but if you plan to save seed you can’t use them, because hybrid plants are essentially a crossbred plant, it takes two different parents to create that variety – your results of saving seed from hybrid produce will not grow true.  As a side note, hybrid plants are not GM (genetically modified).  To explain, that is another post.  There is  a lot of confusion surrounding hybrid and GMO seeds – you won’t find GMO seeds available to the backyard grower.  As well, hybrid and GMO plants are two completely different methods.

Saving seed can be a work of love with a lot of planning thrown in.  Not every type of fruit, vegetable or herb is easy to save and almost everything requires planning before you plant those seeds if you wish to save them!  If you start by planting a hybrid variety (mixed breed), or your plants cross-pollinate with another variety, your saved seed won’t be true.  You will have created, or continued, a hybrid variety of plant that cannot reliably produce the type of vegetable you are expecting – if it even grows at all.  Sometimes, the plant will grow but won’t produce fruit. Luckily there are some pretty fool proof vegetables to save seed from and it doesn’t have to be complicated if you want to stay simple. Keeping the seed pure is pretty important though, so always use open pollinated or heirloom varieties of seeds if you wish to save seed from the plants you grow.  That is the first step to a foolproof seed saving experience.  If you want to produce your very own hybrids, that is certainly possible but beyond the scope of this article.

Tip: You can generally tell if a seed is a hybrid by it’s name – if it has an “F1” in front of it, it’s a hybrid.  The description on the front or back will also tell you.  If you’re still not sure, google has always been my friend when it comes to looking up varieties to see if they are hybrids or not!

So, how does one go about planting a garden with the intent to save some seed?  Well, to prevent cross pollination, some plants need to be a certain distance apart, require taller plants (that they cannot cross with) planted in between them to act as a barrier, or require fine mesh bags over their blossoms while in bloom.  You could also cage your plants or plant some vegetables so their blooms are staggered (and thus reduce the chance of cross pollination). Some plants don’t produce seed until the next growing season, so you will need to keep them alive through the winter. These are all things you will need to take into consideration when planning your garden. You may need to hand pollinate if you are using blossom bags to ensure purity.  Another option is to stagger planting times so two or more varieties in the same family that you wish to save are not in bloom at the same time. Keep an eye on days to maturity and your growing season so you don’t end up with some plants not being mature until after your first frost!  That is especially important if you are growing a warm weather crop that requires time to over ripen or dry on the vine.

You want to save seed only from healthy plants that are producing well and look for plants that display characteristics that are important to you in your climate – such as bolt resistance (perhaps you planted a row of greens and you notice a few are slow to bolt – pick those plants to save seed from if they are otherwise healthy), pest resistance, etc. You don’t want to select just the biggest and best vegetable because that will negatively affect your long term growing. Instead, choose vegetables from a wide selection of plants that are growing true to type and pick the best vegetables that are true to type (even if they are not the biggest) and growing on plants that are healthy and producing well. Of course, you will not want to save seed from plants that have been stunted, diseased, ravished by pests, or is otherwise compromised.

Your seeds, over time, can grow a type of immunity against disease and learn to grow – and grow well – in your soil conditions.  In order to keep growing healthy, vigorous plants you need to save seed only from the best plants. That may mean sacrificing your best vegetables if you have only grown a few plants, if they are your best true-to-type examples.   Luckily with some plants, like tomatoes, you can save seed when you pull them off the vine and prepare to eat them. However with others, such as cucumbers, squash, beans and peas (and more), you will need to let them over-ripen (past the point of being edible), or dry right on the vine.

This brings up another important point – you will want to grow enough plants to be able to BE selective and SEE which plants display characteristics you want. A few plants of this and that will not give you enough to be able to be that selective. If you only grow a few tomato plants, for example, and none of your tomatoes grow true to type, you will not want to save seed from any of those plants! Having a large selection is key. We need to keep in mind that vegetables are constantly changing depending on our growing conditions, weather, pests, disease, etc. What we save is what we will grow, and if we aren’t careful and choose vegetables to save seed from that are not the best representations of what we want to grow, your entire future crop will begin to go downhill and your options for selecting true to type seeds will dwindle.

Once you have figured out when and how to grow the plants, you need to learn when and how to save seed.  Some plants will need to dry on the vine, and you save their seed once you pluck them from the vine. Others need to over-ripen several weeks past the point of being edible but should not be allowed to completely dry on the vine (seed will rot), some plants won’t produce seed until the next year (so you will need to make plans to either keep them protected over the winter if you live in a cold winter climate), or pull them and over winter them in your home(and learn how to do that, as different veggies vary in proper procedure).  Seed saving procedures vary from plant to plant. Tomatoes seeds need to undergo a fermentation process to remove the gel covering, but the majority of seeds can easily be dried either in the pod (on the vine), or simply set out to air dry.

Having said all of that, my best advice to the new seed saver is this: Pick a single vegetable or two for starters. Pick the easiest vegetables that don’t require any fancy planning or techniques – tomatoes, beans and peas are the most popular.  Do your own research on which varieties to plant.  Then, do it.  The next year, plant those seeds (mark them somehow so you can tell which is saved, and which seed was purchased if you plant both).  Keep records through the growing season to track their performance.  Save seed from the best fruits. And do it all over again.  Each year, add one or two similar plants to the seed saving repertoire.  After a few years you will have the hang of the easy stuff.   Take it easy, go slow, and most importantly find the joy in growing more self sufficient.

I will post more on this topic!