Where are the seeds? The seeds are always where the flowers were, because the seeds grow at the bottom of the style (the bit that sticks up in the middle of the flower). Sometimes, the seed pod forms behind the flower (as in daffodil), but most of the time, the seed pod grows inside the flower at the bottom of the style.
When do I collect the seeds? You cannot collect seeds from dead flowers. The seeds need to mature and then they need to ripen. Think of an apple - you know you can't eat the little green apples that you see when the flowers have died. It's the same with other seed containers - they need to grow bigger and mature before they are any good. Seed production is a three-stage process: first, the seeds have to be fertilised, then they have to mature, then they have to ripen. If they haven't been fertilised, they won't mature. If they haven't been fertilised and grown to maturity, they won't ripen. If they haven't been fertilised, matured, and ripened, they won't be viable. Sometimes, it takes weeks or even months from the time the flower dies to when the seeds are ready.
How do I tell if they're ripe? When the seeds are ripe, nature will disperse them. If you want to collect them yourself, you need to wait until just before they would be dispersed naturally, because you know that they will be ripe then. The seed pod will become dry and will usually change colour, probably from green to brown or white, and the seeds inside will change from green or white to brown or black. Think of the apple again - the seeds inside an unripe apple are white. When the apple is ripe, it changes colour and the seeds inside become brown.
How do I know if seeds are viable? Viable seeds are healthy seeds. Often, they look healthy - they're shiny, fat, heavy and tough (all relative to the weight and size of a seed). Sometimes, they aren't all those things, but a good seed - even a flat one like a lily - will still have a bit of 'body' where the embryo is, or be too strong to squash or cut with a finger nail.
What are Open-Pollinated Seeds? Left to the bees and other natural pollinators, plants produce seeds that are the result of pollination with any other compatible plants in the area. Open-pollinated seeds are what you get naturally. Seeds saved from open-pollinated plants will give you more or less the same mixture of colours, sizes or heights as the original plants.
What are Hybrids? Hybrids are plants with mixed parentage. They're plants with a large number of genes for different things (colour, height, size of flowers) in them, so you get a mixture of colours, heights and flower size from their seeds. If seed growers have selected one thing, such as colour, and grown only the plants that have flowers with that colour, and collected seeds from only that colour, and done that for several generations of plants, you'll end up with plants that have mostly that colour flowers. However, they will still have a few genes for other colours, and if they are grown near other plants of the same type with other colour flowers, they will cross-fertilise and the seeds will have genes for all the colours, and will produce plants with different colours.
What are F1 Hybrids? F1 Hybrids are seeds of two particular plants that growers have cross-pollinated. They are the first generation of plants produced from the cross, and can only be produced by crossing the two particular parent plants again. Seed saved from F1 plants will not produce the F1 hybrid. They are then open-pollinated.
Can I grow Heirloom plants? Heirloom varieties are usually vegetables that have been grown in isolation in a particular area, and have been selected over generations (of people and plants) to produce the best crop in that area, because they have been shown to grow best in whatever the local conditions are. If you grow heirloom varieties somewhere else, they may not do as well as in their original location. You will also need to prevent them cross-pollinating with other compatible varieties, or they will not remain true to type.
Why has the seed from my white flowers produced blue flowers? White flowers are often only a deformed type of a flower that is normally blue. The plant therefore carries the blue genes (blue 'runs in the family'), so the offspring will often go back to being blue.
Here's another summary on collecting seeds that has good tips!
Gathering seeds is a matter of timing. For each plant, there is one time when the seeds have matured and have not yet been distributed by nature in the manner intended by the design of the seed pod, the flower head, or the seed itself. If the flower head has dried and turned brown on the stem, or if the seed pods have turned brown and are starting to split open, or you can hear the seeds rattle when you shake the pod, or if you can see that animals or birds are eating the fruit, then the seeds are ready to gather. Gather the seeds prematurely, and you make the task of cleaning the seed both difficult and time consuming. Wait too long, and the seeds will have dropped to the ground, flown away in the wind, been broadcast by exploding seed pods, or eaten. Determining the correct time to gather
mature seeds is done by careful observation. There is no substitute for observation. Example #1: from Aster crego to Classic zinnia, there are any number of plants that are still in full bloom on the day of your first killing frost. There is little to gain by collecting the flower heads when 5 or 10% of the seeds have ripened. Wait until the first nice day in February to collect those flower heads; they may have been frozen in time, but now all the seeds will have ripened and be easier to extract. Example #2: You want to save seeds from your eggplant or squash. The seeds from either
are immature when the fruit is ripe enough for you to eat. Collect your seed from these mature oversize seed pods after they have been left in the garden fully a month after you have cleaned up in preparation for winter. Nature considers these seeds to be ripe about the time their containers have been destroyed by the weather. Note that there is
minimum of thirty days difference between deadheading flowers to promote additional flowering and cutting flower heads for seed collection.
When you have decided to collect the seeds for a particular plant, cut the stems, invert them, and shake against the inside of the bucket. If most of the seeds fall into the bucket, you have found the method for that type of plant. In few cases, the flower heads will need to be shredded before they release their seeds. In the case of fruit or vegetables, the seeds will have to be extracted with mechanical assistance much of the time. If the work is tedious and seems not worth the effort, either your timing or your method need to be improved. Example: you have collected the blackened
heads of purple coneflowers, but prying the seeds out is a chore. Simply leave the heads out in freezing weather, and in time, all the seeds will have extracted themselves into your container. Another example: puree a whole tomato in your food processor; pour the contents into a glass; cover with a paper towel; let sit for three or four days to ferment; strain out and dry the seeds for storage. Put nature to work for you whenever possible. You will pay a high price for careless collection technique or timing, in that your cleaning chore is multiplied from 10 to 100 fold. Seventy-five percent of all the seeds I collect require no cleaning whatever because I use the right
moment and the right method. Do not snip off flower heads into a paper bag. That is the surest method of losing the seeds to mold; and it is guaranteed to make seed cleaning the most time consuming chore you encounter all year long. Examine the flower head or seed pod carefully. Think! Use your head to tap-out, blow-out, or pluck-out just
the mature fully ripened seeds without any chaff. As a general rule, consider seeds which are not easily released as being immature, too damp to collect, or both.
The source for the above information is http://tomclothier.hort.net/page28.html Consult this website for further
instructions on cleaning the seeds and storing them. Another source for basic seed information can be obtained at