If you are delighted with the results from a particular variety of tomato or cucumber, or notice that your lupines looked especially good this year, why not think about saving some seeds from those plants? You will be selecting seed from the plants that please you most with their performance and are best suited to your growing conditions. It is sometimes difficult to find the varieties that you really want in catalogues or stores. This way you guarantee your own supply and you preserve heirloom varieties. However do look carefully at the original seed packets. Avoid seeds marked F1 or F1 Hybrid as the plants may be sterile or produce a majority of offspring unlike themselves.
Do you have more than one variety of the same plant growing close together? You may have some cross-pollination going on and this can lead to some strange looking offspring! Anyone who has ever put old tomato plants in the compost will know that the seedlings that sprout the next spring can be interesting! Ideally you need a way to keep the pollen from any one variety from reaching the others. A physical barrier can be as elaborate as a wood framed cage of window screen or as simple as a length of row cover. For tall plants where it is not practical to cover the whole plant enclose just the flower. This can be done with nylon mesh or paper bags tied loosely round the stems. As long as air can travel through but not insects, any material will do.
However do remember that the flowers still need to be pollinated. Tomatoes, peppers, beans and peas are largely self-pollinated and this is not a problem. Tomatoes and peppers benefit from having the flowers shaken gently, which is what happens naturally when a bee lands on such a flower. Some other plants may need hand pollinating. Pollen can be transferred from the anther (that little oblong bulb at the tip of the stamen) to the tip of the female part – the pistil – of the flower. Fine paintbrushes are perfect for this job and I certainly find that I need either my glasses or a magnifying glass. Try to take pollen from one plant and place it on the pistil of a second plant. Such a cross will result in a more genetically diverse collection of seed. Remember to recover the flower and keep it covered until the fruit has begun to form.
Now you just have to wait for the seedpods to mature and ripen. Collecting seed too early will cause seeds to not be viable. Pods will change colour from green to brown and begin to dry out. You can tie a paper bag over the maturing seed heads to collect seed. Cut the stems and hang upside down in a dry place until the heads split and drop the seeds into the bag. You want to clean as much debris as possible from the seed. Any chaff left may hold moisture or mould which will kill the seed. I use a shallow bowl to separate the seed. Generally the seed is heavier and will fall to the bottom of the bowl and you can just pick the debris from the top.
Remember to keep the seeds in a cool, dry area exposed to the air until they are ready to store. I usually lay my seeds on plastic plates as I find that the seeds sometimes stick to paper plates or towels. When the seeds are completely dry they will break rather than bend. It may take several weeks to reach this stage so if you have a rarely used spare room this is an ideal place.
Once the seeds are completely dry store in an airtight container such as baby food jars or old film canisters. A small piece of paper towel will help keep the seeds dry. Always label the variety, date and any other important information such as preferred planting conditions. The containers should be stored in a cool dark place. An unheated spare bedroom, a closet or refrigerator are ideal. Avoid opening the containers until you are ready to plant. If the seed is properly stored it should be viable for years.
Some seeds require special treatment to prepare them for drying or may require stratification before sowing. Harvest peppers when they are mature and fully ripe. Cut the bottom of the fruit and carefully reach in to strip the seeds from the central core. Follow the procedures already outlined.
Tomato seeds require a little more work. Allow to completely ripen. Cut the tomato in half, opening the vertical cavities that contain the seed. Gently squeeze the juice and seeds into a bowl. The seeds are encased in a gelatinous coating in order to prevent them from sprouting inside the tomato. Place the jelly and seeds into a small jar or glass – you may want to add a little water if you are only processing one or two tomatoes. Loosely cover and place in a warm location for 3 or 4 days, stirring once a day. This mimics the natural rotting of the fruit and you will be able to rub off the coating. Don’t worry if you see a layer of fungus on top of the mixture. This fungus eats the gelatinous coating and also produces antibiotics that help to control seed borne diseases. After 3 days fill the seed container with warm water and let the contents settle. Carefully pour out the water along with pulp and any immature seeds. Viable seeds are heavier and will settle on the bottom of the jar. Repeat until the water is almost clear and clean seeds line the bottom of the jar. Pour the seeds into a fine mesh strainer, drain and invert onto a paper towel. Allow to dry completely as outlined earlier. As the seeds are small this will probably take only a few days. Cucumber seed can be cleaned in the same manner.
Berries and fruits often have tough seed coats that need stratifying with cold before they will germinate. Gather in the fall when they are fully ripe, crush by braking down the pulp and exposing the seed coat. Mix the crushed fruits with twice their bulk of silver sand. Put in pots, cover with hardware screen and leave outside for the winter to freeze and thaw. Mice and squirrels will find them tasty so you do need to protect the pots in some way. If you have a spare refrigerator you can store the pots in there. In the spring the seeds may have already sprouted by them selves or you can replant them individually. Some tree seeds such as maple, holly and hawthorn may require 16 to 18 months to germinate, so don’t throw them out until you are really sure that they are not viable.
If you raise and save your own seeds you can produce plants best suited to your climate and your gardening conditions. Flavour, pest and disease resistance, early bearing and size are among the many characteristics that can be enhanced by careful selection over a period of years. Best of all you have the satisfaction of saving your own seeds. Plus you will save yourself some money, so go ahead and give it a try!