Throughout this warmest time of the year, there is do much going on in the garden that you may be forgiven for not thinking about the future. But it is well worth taking some time now to think about next year's garden. Seed saving is an essential part of sustainable gardening. It is easier than you might imagine to save some common seeds for use next year. Saving seeds will allow you to built up a bank of edible plants that will do better and better in your garden year on year.
You can save the seeds of any open pollinating lettuce plants. Hybrid varieties will not come true so you should only try to save the seeds from heirloom or open pollinating plants. You may find at this time of year that some of your lettuce plants have begun to bolt – that is, they will have thrown up flower stalks and may even have reached the stage of setting seed. Simply leaving lettuce plants alone for a few weeks will allow them to do as nature intended and begin to work towards completing their life cycle.
After blooming lettuce seeds will take somewhere in the region of twelve to twenty four days to get to the point where the seeds are ripe. There are a lot of different varieties of lettuce of course, and if you are saving seeds then you should isolate each variety by covering it if there is more than one variety blooming at the same time. Collecting seeds from your healthiest plants mid-season is a good way to ensure a good quality of seed. To get plenty of seed for next year you will usually only have to collect seeds from one or two of the best plants of each variety that you wish to grow.
There are various ways to collect lettuce seeds. One of the simplest ways is to wait until the lettuce seed heads are drying out but have not quite dried out entirely. You should they take each plant and hang it upside down in a dry, cool place in a paper bag for a couple of weeks to dry out fully. Seeds, along with the chaff and some debris, will fall into the bottom of the bag. This method ensures that you do not leave the seed heads too long and end up losing most of them in a strong breeze one day.
After you have collected the dried seeds and chaff, place them in a large bowl. Separate the seeds from any larger plant pieces. Winnow the seed by gently swirling the bowl and blowing air over the pile of seed and chaff. The lighter chaff will be separated and can be blown out of the bowl. If there is lots of dust in with the seed then you can shake it gently over a fine sieve. Continue to process until the seeds are left with very little other plant material. Once this is done then you can simply label and package the seeds and store them with any other seeds you have.